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Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby Burgerman » 29 May 2014, 13:55

http://www.metrompg.com/posts/alternator-optional.htm

Interesting...

Seems to me that all you need do is use a switch, brake switch, inertia switch, link to fuel injection to detect low injector pulsewidth etc to activate alternator at any time you are decelerating.

LEAVE ignition light wire alone...
Connect alternator to battery via heavy wire wound resistor with a value that only allows say 2 amps max to flow if battery is 11.2v (dead) when charging. The alternator tries to put out 14.4 to 14.5v regulated usually. This means it will only charge at a negligible 1 amp (ish) normally through the resistor. That will use negligible power and it will have almost no EMF or fuel cost. And wont hurt it. (I think...) Or you may need a small bulb from alternator output to ignition light connection? Research...

When braking etc, bypass the resistor with a solid link via a DC to DC solid state relay. So it charges at whatever amps it takes to pull the battery up to 14.4v.

And 45psi in the tyres, 0-20 oil, lower car, oil rather than grease in wheel bearings and CV joints, tape over all joints, and add some two stroke oil to the fuel tank. That gives smoother more complete combustion, and makes it run better too.

And only go downhill...
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Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby paulgato » 30 May 2014, 07:30

Well, I did get the 'new' (used) alternator installed yesterday just before the rain started.

Thanks for the link. That guy also posts on http://www.ecomodder.com, which I find to be a good resource. I have a thread there where I've been documenting this particular project.. It's long and rambling but there is some good solid data there too, such as the current consumption of every piece of equipment in the car...

http://ecomodder.com/forum/showthread.p ... 27179.html

Seems to me that all you need do is use a switch, brake switch, inertia switch, link to fuel injection to detect low injector pulsewidth etc to activate alternator at any time you are decelerating.


I might try some of those things but first I need a way to stop and start the alternator while driving.

LEAVE ignition light wire alone...
Connect alternator to battery via heavy wire wound resistor with a value that only allows say 2 amps max to flow if battery is 11.2v (dead) when charging. /.../ When braking etc, bypass the resistor with a solid link via a DC to DC solid state relay.


This is interesting. I hadn't considered interrupting the main charge wire, but if it were connected with a permanent resistor in series which is bridged out on demand there'd be no risk of voltage spikes I guess. In fact my original idea was to use a deep cycle battery and a DC/DC converter set to output say 20A at 14.7v. The alternator would then 'see' that 14.7v on its battery +ve reference or sense wire and would conclude that its services were not required. And if the current demand was greater than the 20A the voltage would drop and the alternator would make up the difference. I liked that idea precisely because I wouldn't have had to change the car's electrical system in any way (and wouldn't risk breaking any alternators - ha ha.) I didn't find a suitable voltage-adjustable converter though, so went with interrupting the field exciter wire instead. I'm still thinking that using the sense wire would work, as that is what the alternator already uses to adjust its output from 0A to 90A. In theory I'd just need to switch that sense wire between its existing connection point and a voltage source which I can control, and which will be high enough that it will stop the alternator from charging. Depending on how much current is drawn by the regulator via that 'sense' wire, the new source could be as simple as a NiCad battery pack, or could be a small, low current DC/DC step-up converter.

And 45psi in the tyres, 0-20 oil, lower car, oil rather than grease in wheel bearings and CV joints, tape over all joints, and add some two stroke oil to the fuel tank. That gives smoother more complete combustion, and makes it run better too.


51psi in the (LRR) tyres for the past year with no issues. (Corners much better with harder tyres too.) I changed the gear oil and put some Molyslip in - that was dead easy, cheap and made an immediate, obvious reduction in rolling resistance. Oil in bearings/CV joint? Won't it fall out/wash out? I've heard of folks using synthetic grease in wheel bearings. Two stroke oil in fuel...? Really? That makes me a bit nervous - those 30,000 psi injection pumps are expensive and sensitive.

All good suggestions but I've become a bit bogged down with this 'alternator delete' project so I feel I have to focus first on getting the basic battery charge/discharge system up and running and properly installed/safe/reliable/neat before getting too involved with other things. I've had good mpg gains from plugging the car into the mains every night, but it's been taking huge amounts of time, and I'm looking forward to finishing it.
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Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby Burgerman » 30 May 2014, 10:30

51psi in the (LRR) tyres for the past year with no issues. (Corners much better with harder tyres too.) I changed the gear oil and put some Molyslip in - that was dead easy, cheap and made an immediate, obvious reduction in rolling resistance. Oil in bearings/CV joint? Won't it fall out/wash out? I've heard of folks using synthetic grease in wheel bearings. Two stroke oil in fuel...? Really? That makes me a bit nervous - those 30,000 psi injection pumps are expensive and sensitive.


Moly slip is snake oil.

So is PTFE, and all the other additives.

I built automotive rolling road dynamometers, nitrous injection systems, and race engines for drag bikes and cars for many years.

Oil in bearings is kept there by seals. cant leak or wash out, same with CV joints. Two stroke oil at around 200 to one will make your engine both quieter and get rid of the clatter when cold and run more efficiently. Wont hurt anything. Premix it with a gallon of fuel, and tip it in...
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Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby paulgato » 30 May 2014, 14:07

We will have to disagree about Molyslip Mr Burgerman. I've used it for 30 years in both gearboxes and engines. I don't use it in my present engine though. I use the 'Longlife' oil that the VW dealer tries to charge £44 a can for (!) but I'm sure it helped in the gearbox. I suspect that engine oils have improved a lot and now Molyslip doesn't help much. I tried it in this engine once but couldn't detect any improvement.

In my lazy youth I used to sometimes add half a can of Molyslip to an engine that was overdue for an oil change, and you could hear (and feel) a very obvious difference: it sounded like the oil had been changed when all I'd done was pour 150ml of grey gunk in. (Quieter, more free-revving.) Engines would also run measurably cooler with Molyslip. I agree about Slick 50 though (PTFE). I tried that in a petrol engine once, many years ago. It did work, but it only had an effect until the oil was next changed, nothing like the "50,000 mile protection" they claimed, plus it was expensive, so I went back to using Molyslip.

I read up on putting two-stroke oil in the diesel tank. It seems many people swear by it. I might give it a go at some point, but I'll do some more research first, just to be on the safe side. Do you use that yourself?

One thing that has a very marked effect in this car is using premium diesel. I use Shell Ultimate diesel. More expensive, but for my car at least it pays for itself in increased mpg. From memory the mpg boost was about 7% and the extra cost was 6%, so only a marginal COST benefit, but it also made the engine run much more smoothly. (Perhaps they put two-stroke oil in it - ha ha.)
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Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby Burgerman » 30 May 2014, 15:21

When working for bike magazines (performance bikes) I tested every oil additive and many oils to find out for sure. Several bikes, and under controlled conditions using my own inertial chassis computerised dynamometer. Controlled air, engine, oil temperatures, corrected for pressure, temperature and humidity.

No additive had any affect on any power curve at all. Only changing oil grade had any affect. And that was under 1 percent overall. Wynns, STP, Molyslip, Slick 50, etc etc. All a waste of money.

Molyslip is just Molebnium Disulfide in a cheap base oil. Its a friction additive. And decent oil already contains a package of friction modifiers and detergents, high pressure long chain molecules for high film strength etc.

Adding stuff to it can make the oil worse. For e.g., too much Zinc (another additive) causes cams to get pitted. Too much moly or other friction modifier causes roller or ball bearing races to slide instead of rolling. That causes flat spots, and subsequent failure. Same with roller cam followers etc.

Do yourself a favour, use a quality modern thin synthetic like 10w20 mobil synthetic and don't mess with its carefully engineered balanced package.
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Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby paulgato » 30 May 2014, 16:40

Interesting. Perhaps we don't disagree that much. I do think it is pointless to add anything to the good quality synthetic oil I am currently using, but it most certainly improved the old mineral oil I was using in engines years ago.

I say "I changed" the gear oil a year or so ago and noticed that very dramatic improvement in rolling resistance, but in fact I got my local mechanic to do it. It took him ten minutes on the ramp but would have taken me a couple of hours grubbing about under the car on a muddy driveway. I got him to put the new oil and the Molyslip in at the same time of course, so it was not a scientific test. The improvement could, I suppose, have been entirely due to having new oil in there, although VW don't specify any replacement interval for the gear oil. They claim that it can be left in there forever. (They're probably lying, to make it look like their cars need less maintenance than they actually do, but that's what they say.) I used the latest version of the recommended VW gear oil.

So it may be that my opinion on Molyslip is out of date, or it may be that every time I added Molyslip to existing oil in gearboxes and noticed an improvement - both in rolling and in shifting - it was because the existing gear oil was old and tired, and the addition of Molyslip compensated for that.
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Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby Burgerman » 30 May 2014, 17:34

The improvement could, I suppose, have been entirely due to having new oil in there, although VW don't specify any replacement interval for the gear oil. They claim that it can be left in there forever. (They're probably lying, to make it look like their cars need less maintenance than they actually do, but that's what they say.) I used the latest version of the recommended VW gear oil.


The problem is that unless you can do your back to back tests in scientifically controlled conditions, with an accurate digital dynamometer to plot rear wheel BHP in a controlled test cell, as I did, then you cant really know. Measuring MPG on the streets, and subjective feelings, do not give accurate results. People that have just had a car valeted, or serviced will tell you it runs better and is quieter, does more to the gallon. When its simply not true. They FEEL that this is the case, the Dyno says not...

Testimonials are pretty meaningless, and the placebo effect of adding something you expect to do some good all makes it seem real enough.

You change engine oil because the corrosion inhibitors, and detergents get used up, and because it gets loaded up with carbon. There's no corrosion inhibitor or detergents in gear oils. And no carbon getting past the pistons. And no acids from combustion. And so no need to ever change gear oil. Its true that some steel from bearings and gear teeth (wear) would contaminate the oil over very high mileages, but they fit magnetic traps to grab that and hold it in one spot. After extreme mileages around 10x that of the life of the vehicle, there may be some measurable viscosity change too, but its so small as to be not worth worrying about. And its in the direction of lowering viscosity as long chains get cut up. Hence most manufacturers quote top up or check intervals but no oil change for the life of the vehicle.
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Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby paulgato » 30 May 2014, 19:06

I'm certainly not doubting the results of your scientific tests with the dynometer (?) and as I say I'm not sure whether the improvement after the gear oil change was due to changing the oil for fresh oil or the addition of Molyslip, but the effect was not just subjective and was very dramatic. Or maybe the newer version of VW gear oil is much better than that installed ten years earlier when the car was built?

I actually didn't think changing the gear oil would have much of an effect; it was just that it was so cheap and easy to do I thought I might as well eliminate that possible source of friction. I remember driving away from the garage and being amazed at how much further the car would roll in neutral down familiar stretches of local road. I then took it on a local 'test route' where I measure the effect on mpg of various changes. That route is a straight stretch of dual carriageway of about 5 miles, where cars can safely overtake me, and where I can set the cruise control to 50mph and set the car's mpg trip meter at a certain point and note the mpg average at another point at the end of the circuit. It's a two-way test run, incorporating a roundabout at the half-way point. The roundabout is not taken at 50mph (!) so there is some possible variation in driving efficiency at that point, but after the gear oil change I got my highest ever reading, beating my previous best reading by about 4 mpg. (about 5%) I know there can be many reasons for variations in mpg, including atmospheric variations, but it was a very still morning, and the fact that it was my best ever reading by a margin tells me it wasn't just favourable weather.

I try to test all the changes I make. Obviously some of my judegments are subjective, but some are a bit more measured. When I first started monitoring my overall average mpg closely the car was getting (as shown on the dash) about 55mpg. A year later (same approx ambient temperature) it was showing 83mpg. Now it's showing about 93mpg, and I expect it to improve as the weather warms up over the summer. (The dash mpg meter is optimistic by about 7%.)

Once the alternator-delete project is done and dusted and stabilised, I have a few things on my list to try next. I'll add to that list the wheel bearing lubricant change, and possibly this two-stroke oil thing. Also a full underbody fairing, and stripping a bit of unnecessary weight such as the A/C system, roof rails, and anything else that has no function but which won't make the car look too weird when removed. I'd like to try another engine re-map. The first one I think made the car more efficient in an absolute sense but made it much more difficult to drive slowly and frugally in the real world, so I had it put back to standard.
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Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby Burgerman » 30 May 2014, 19:17

You cant measure fuel economy to 5 percent like that. Far too many environmental and vehicle variables.

I have done this oil thing on diesels many times. Humour me. Go buy some cheap (cheaper the better) 2 stroke oil, or even engine oil. Mix enough oil/fuel in a can to get an approx. 100 to 200 to 1 mix in your tank. Not remotely critical. Tip it in and top up tank to mix it.

Then tell me its not quieter and smoother, especially from cold. And gains MPG and theres zero smoke. Its not just subjective like a quick MPG test is, its measurable on a Dynamometer. Ask me how I know!

I used to design and build computerised pure digital automotive chassis dynamometers for a living in the 80s, which I got into because all the commercial ones were not accurate enough to do any seriously accurate back to back testing on the drag bike and car motors I was building for customers...
I build my own fuel injection, turbo, and nitrous injection systems too. Serious stuff that gets around 550 BHP per litre from a bike engine.

Build yourself a nitrous injection system for your car cheaply!
http://www.nitrous.info one of my 20 year old sites...
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Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby paulgato » 30 May 2014, 20:36

You're clearly the man to ask about these things Bugerman, and I will try the two-stroke thing once I have done my own 'due diligence' on the subject, and once the alternator delete thing is done. (Though maybe not the NO2 thing right now! Interesting to read though.) I will remember to let you know the results. I try to only make one change at a time so I have a better chance of testing whether it works or not - preferably over at least one full tank of fuel.

The testing thing is difficult. Dyno testing is not posssible for the vast majority of us. The accepted standard out here 'on the streets' is to do A-B-A testing, where you test, make the change, test, change back to standard, test again. For some things that's possible; for some it's not. The testing I did to determine the projected effect of driving without using the alternator was possible to do in that way; use of fuel additives is not so easy, as you can't take the additive out of the tank once it's in there. (Then the best you can do is an AAA-BBB test.) Tests like this should be done on a calm day and in quick succession after thoroughly heat-soaking the engine. (I often do test runs on familiar local roads after coming back from a long journey, before going home, when I know the engine, drivetrain and tyres are all nicely warmed up and are not going to warm up any further. It generally takes about two hours driving before the mpg will hit its peak.) The weather can make a huge difference (temperature, humidity, water on road surface, air pressure, wind speed) and we all try to take account of that, more or less successfully.

There are judgement calls at every step. Some will be wrong, some will be right. The fact that my overall displayed mpg has gone up over the past 20 months from 55mpg to 93mpg tells me that most of those judgement calls, based on the flawed testing I've been doing, have been right. Sometimes you just KNOW something has got better because its blindingly obvious. The gear oil change was one of those "Oh my god, I didn't think it was going to be THIS much better!" moments, as was getting the front wheel alignment adjusted to zero toe-in, ...and as was my first alternator replacement 18 months ago, which incidentally fixed a rough idling issue that turned out to be due to a frozen alternator freewheel pulley that I didn't even know existed. Suddenly I could cruise smoothly in 5th gear at 26mph at tickover and get stupendous 100+mpg around town in light traffic. And even at 30mph, the slowest I could comfortably drive before in 5th, mpg was WAY up after the alternator change.)
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Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby paulgato » 30 May 2014, 20:39

But seriously, that must be a misprint - surely you meant 55BHP/litre not 550BHP/litre. (!!)
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Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby Burgerman » 30 May 2014, 21:14

No if its any clearer, a stock bike engine of 1072cc with quiet exhaust, stock plugs, not yet run in, makes 136BHP at the wheel.
Same bike with a small amount of nitrous, still otherwise completely stock, (50bhp hit) makes 190BHP rear wheel.

See graph. A stock, quiet, standard inoffensive street bike run 1, and run 2 with Nitrous. http://www.nitrous.info/images/nitrous- ... larger.gif That's half way there and its a stock non turbo bike!!!

My race bike (street drag bike) engine was in a relatively mild state of tune and 30psi and make 285bhp with a basic T4 turbo and a single draw through carb. And that was without nitrous.

My customers drag race only bike engines were making a rear wheel corrected 550BHP with 30lb boost and Nitrous. Or about 650 at the motor.

Heres one, 650bhp 280mph, turbo bike... http://www.youtube.com/watch?v=5BT2JjzHa-c


Bikes are not cars! They make real power. Take a look here. Heres a road going one. Watch till end. There are loads of these about now.
http://www.youtube.com/watch?v=ltjtD9KgDso Same sort of thing, this is 500bhp even without nitrous. Some are 700 nowadays. I am talking 14 years ago!

Want a 500 bhp system/bike? Mr turbo in the us is one of many people that will sell you the stuff you want, see stage 3 http://www.mrturbo.com/turbo-sys/suzuki/busa/busa.html
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Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby paulgato » 30 May 2014, 22:04

Scary stuff.

This is the kind of thing that I get excited about these days...

https://www.youtube.com/watch?v=VRZcg8rkawI
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Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby Burgerman » 30 May 2014, 23:54

http://www.wheelchairdriver.com/solar-p ... riment.htm

Into that too...

And its working great. My summer bills are zero. Or almost so.
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Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby paulgato » 04 Jun 2014, 14:18

Impressive solar set-up.

I like the way you've done things yourself, bit by bit. I'm sure some government energy schemes could be good if they were engineer-driven rather than politician/accountant-driven, but they tend to end up restricting people's choices with inflexible 'tick-box' methods of appraisal and design. That makes it difficult for the user, and turns the installer into a government agent who has no freedom to innovate. There must be a better way. Zero VAT on all insulation/solar/wind kit maybe? ...regardless of who installs it, whether householder, plumber, electrician or Green Deal registered installer?

http://www.accountingweb.co.uk/press/eu ... green-deal

Anyway, well done for avoiding the bureacracy and just doing it. But if you are not on a feed-in tarriff, do you manage to sell any excess watt-hours to the power company or do you just give it away?

As far as the alternator-delete thing goes, I've hit a bit of a problem: the replacement alternator I installed (a Bosch unit from a VW breaker's) turns out to self-excite at 1500rpm, so I can't disable it by unplugging the field/ignition wire as I was doing before. Hmmm... The 'old' one never boot-strapped itself into life, not at any engine speed. That one looked quite clean and new and had no visible label or numbers on it, so it may have been a cheap after-market replacement unit. It worked just fine until I blew its diodes with my tinkering. I guess I could try another used alternator... Or get the 'old' one repaired...

Or, as a last resort ;-) I could always take your advice and interrupt the output cable with an SSR instead. I'm still not sure about that from the point of view of cost, heat, and finding a good place to mount the SSR, etc. Do you think it would be safe to just have a simple ON/OFF isolator switch at the alternator B+ output terminal? Not for controlling it dynamically of course - just so I can leave it OFF most of the time but be able to switch it ON again if I ever need to. Perhaps with the small resistor you suggested, as it will self-excite even with all wires disconnected.

It's funny: I didn't think yer average modern alternators self-excited any more, ...apart from the single-wire ones of course which are designed and sold as being self-exciting. I read somewhere yesterday that it's only the Bosch alternators that tend to self-excite.

Anyway, I think I've found a decent charger...

http://www.shop.sterling-power.com/acat ... Ultra.html

...the 40A model. I was kind of balking at the price but because it's dual output (3-output in fact) I can use it for both the starter and the rear battery so it's not crazy-expensive really. There's a small cubby-hole behind the rear wheel arch with enough space and ventilation. I started running cables through the car today.
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Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby expresso » 05 Jun 2014, 02:39

Hi - i have a question - i may be in the wrong area for this - i am looking to fast charge my chair and want to try getting the wires - etc, what ever is needed

i have a quickie P222 se - which i want to try this on - the batteries are MK 24 SLD G - can anyone link me to the parts needed - wires - connectors - etc, and a good smart charger - i dont know if 20A is a good one to use -

i needed to charge the other day while i was out and my small 7amp charger helped very little - since i didnt have the time to charge long - really 20 mins -

i like to get a good enough charge in the shortest time so i can keep going for the day -

any input would be great - if you can post links to the items - even better for me to check out - i cant seem to find the charger which burgerman is using -

multi stage - 12V 24V 26V etc type charger - i am in the states US - also its not clear to me - if the charger comes with wires connected - lets say Ring Terminals - and i need to have Anderson connectors instead - do i have to end up cutting the wire and making it myself - ?

i like the charger to do both types of batteries in case i change them myself in the future to AGM etc, - thanks
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Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby expresso » 05 Jun 2014, 04:37

would this charger be a good choice for a fast charge setup ?

http://www.batterystuff.com/battery-cha ... 91-75.html


anyone know if this would be good for either Gel or AGM type -
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Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby LROBBINS » 05 Jun 2014, 08:53

That charger looks promising. One of the forum members, JoeC, has had good service from older Schauer chargers used for WC hockey, and this newer one looks to be more flexible; such as not being restricted to 110V AC. I checked the Schauer site, but as usual, specs are scanty. They do say that, although not settable in the field, they can re-program the charger constant-voltage level to a users particular needs, but I saw nothing about the constant voltage to float transition current and so on. I suggest that you write directly to Schauer with a very specific list of what you need and see what they say. The one in the ad you linked already has an SB50 (i.e. Anderson) connector, the same charger in the scanty Schauer on-line catalog has either Piper or Cessna GPU plugs and you don't want that. Those plugs are OK to 1600 Amps!
Ciao,
Lenny
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Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby expresso » 05 Jun 2014, 18:37

i asked a few places to make sure if charger is not too much amps for Gel batteries and the place did not recommend and wont for Gel batteries - telling me its too much for Gel - if it were AGM type - was told its fine to fast charger etc,

now i called MK - waiting for a call back to make sure - i want to know what is the highest safest Amp charger i can use to fast charge with the GEL batteries - since those are the ones i get - would be a waste to buy AGM myself just to fast charge -

i havnt been stuck yet - come close - but if i get new batteries each summer - i can pull thru - i dont want to do something that may damage them or something else - on the chair electronics - then the Vendor can say its my fault etc,

if MK tells me good news and i can do it - etc, or a limit to the amps i can use - i see if its worth it then - i know others do it here on this site - Burgerman for sure - which is great - but i think he does use AGM batteries also - i see what they tell me first before going ahead and waste money -
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Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby Burgerman » 05 Jun 2014, 20:11

Here's what they will tell you...

Charge at up to 1/5th C max. At 13.8 to 14.1v. If they realise you are a mobility user they may say 14.4v.
That means 1/5th of 73Ah for a group 24 MK. So 15A max. However at 13.8v it will take around 40 hours to fully charge. That's what it says in the manual...

Its bull though.
Why do they say this then?
Because its perfectly SAFE and perfectly acceptable to charge a gel battery at a much faster rate (higher amps) as long as you don't exceed 14.1v at room temp and you stop charging at the correct 100thC point. All modern multi stage chargers that can charge at 14.1v (28.2) already do this. The only exception is where the battery will go above 50 centigrade. That only happens in huge battery banks in hotter countries or in warm engine rooms on huge backup systems etc.

They are scared however that you will some use a crap old style non logic controlled multi stage charger, a transformer taper charger etc. And these will go to "too high" volts eventually. That produces gasses. Costs electrolyte, and causes grid corrosion. And can cause a thermal runaway if they don't shut off at the correct point. And most never shut off! This is all antique advice that belongs in the previous century.

But most likely you will talk to some retard without a clue, as these are the sort of people that get put on those duties... So god knows what they will tell you.
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Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby expresso » 05 Jun 2014, 20:51

yes thats the feeling i got - they are not sure who the end user is and what charger they will use - or know how etc, and cant be sure - so to be safe - they say not good

i called a place to ask - i was going to purchase - but they didnt want to recommend or sell it to me for a GEL battery - it was a 20 amp model - i called quickie and asked - one guy the other day should be fine but didnt get how much amp can i use safely - today - i was told he cant say because they dont do it - they used to do it from quickie years ago i was told -

was told that 20 amps too high and can make the Gel in there melt to water and wont gel up again - battery life will suffer alot - if that happenes - my wheelchair tech told me - should be fine but cant say if a rush of incoming current etc, can or may damage the electronics - even though its not being charged from chairs wiring etc, - the electronics still play a part or get affected - he will be at my place tomorrow i ask again

and i placed a called to MK - waitng for the person to call me back - i like to hear it from MK as to what is the safe amount i can use -

from the place i called to purchase - was told if using AGM - then it should be fine - but GEL they didnt want to sell or recommend anything faster -

i may be able to get new batteries now hopefully - if thats the case - i be fine for the summer months - -- even if i get new batteries now - i will charge when out if i find a outlet - plug it in for 30 mins at least - even if i still have all my greans to keep it full and can go longer in the day riding - i know when i reach a certain area when i ride - that i will loose the grean soon - and once i do - goes down hill much faster once grean is out -

now its making me worry if i damage something - they will say its my fault etc, insurance - this and that - since they give us MK GEL batteries - dont have a choice - i have to work with what i get -
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Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby Burgerman » 05 Jun 2014, 21:20

was told that 20 amps too high and can make the Gel in there melt to water and wont gel up again - battery life will suffer alot - if that happenes - my wheelchair tech told me - should be fine but cant say if a rush of incoming current etc, can or may damage the electronics - even though its not being charged from chairs wiring etc, - the electronics still play a part or get affected - he will be at my place tomorrow i ask again


Electronics are not affected or involved. They only see the same 14.1, 14.4, 14.7v (or double this for a pair) that the different batteries max charge voltage determines. They are all good to over 32 volts anyway! For reasons of regeneration. You are talking to retards.

The gel IS already water...

Its a mix of plain old Sulphuric Acid, WATER, just like all lead batteries. The only difference is this:

They add SILICA GEL fine crystals to the WATER/ACID electrolyte mixture to create a thixotropic paste. A GELLED ELECTROLYTE. Otherwise its exactly the same as every other battery. Each lead plate gets a thin layer of gelled electrolyte (GEL) and the plates are all separated with a fine mesh and are all pressed together.

An AGM battery uses a fibreglass mat as the separator, and plain WATER/ACID without any Silica Gel.

IF you charge a lead battery at up to 14.1v no or almost no gasses are given off. Amps make no difference. As long as you do not exceed 14.1v there are no BUBBLES produced. At ANY amps. Bubbles are the enemy of GEL batteries because they push the GEL away from the plates and create voids. These voids never recover. AMPS no problem VOLTS above 14.1v big problem long term... You battery dies early.

You can charge AGM batteries to 14.4v. Because they have no gel. At this voltage some small bubbles are produced, and RECOMBINED by the battery into water. (Hydrogen and Oxygen are produced and when recombined they make a little heat and water). This doesn't bother the AGM because there is no thick GEL. So the electrolyte just soaks back into the GLASS MAT separator.

BETTER AGM batteries use PURE lead. These have no impurities or strengthening materials, such as zinc, calcium, etc and they produce no gas until a slightly higher voltage. These are the likes of the ODYSSEY, OPTIMA, and clones and rebrands. These can be charged at 14.7v and can recombine the small amount of gas produced. They have lower Peukert and lower IR levels. And charge faster. Better al round!

In all cases with a lead based no gas is ever produced until its charged. At which point even a huge charger (I use 100A often) will only be charging at a low Amp rate. Amps fall away as the battery voltage rises up. So its COMPLETELY SAFE if you charge at an accurately controlled CORRECT voltage.

Feel free to read your mass of contradictory emails! :ugeek:
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Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby expresso » 05 Jun 2014, 21:40

this makes it confusing to me -

what smart charger do you recommend for my situation if i decided to do this anyway - i would be using MK GEL batteries - these are the specs - http://www.mkbattery.com/images/M24SLDG.pdf

i was gun ho yesterday to do it - now i am mixed - partly because i may be getting new batteries now - and if thats the case - they will last for me during the next few months which is when i use it often enough -

i need fresh new sets for each summer - then i be fine - now if i dont get them now - for what ever reason - i would want to do the fast charge setup -

lets say i want to do it - can you link me to a decent smart charger that would work for me - i like to keep it compact - i need to carry it my backpack but cant have a huge brick at 20 pounds to lug around - i cant even lift that - haha

small compact and light as possible - i seen your multi voltage charger but cant find it anywhere -

thanks
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Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby Burgerman » 05 Jun 2014, 22:05

Here's the problem.

Gels are specialist. There are very few used other than in some powerchairs (Most are AGMs because they are cheap). So almost every universal 3stage charger CLAIMS to be GEL friendly, and then charges at a fixed 14.4v which reduces service life markedly. Also most chargers do not give full specs, so you have no idea at what point in the charge (CV stage) they actually go "done" and revert to Float. Finding one that actually charges at CV 14.1 (28.2) volts can be hard or expensive (marine) etc.

GEL batteries like all batteries last a long time if FULLY recharged. That means you MUST charge them for 12 to 16 hours depending on discharge level. Which is not very practical. You charger will say "done" after around 8 or 9 hours. Its not. That just means it reached the end of CV stage. Its now on FLOAT. That completes the charge later on. (that time is halved by the Odyssey for eg as these charge faster)

The bigger the charger the more you get back into them fast, leaving more time on CV and Float at the end of charge. So contrary to the advice you will get from the usual idiots, a big charger will make a deep cycle battery last longer if only because it ends up getting a more complete charge. And that's why Odyssey recommend a MINIMUM of 1/5th C charge rate! The more Amps the better.
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Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby expresso » 05 Jun 2014, 23:07

Ok i got the Call back from MK - and the guy was very nice - he told me - its fine at 20 amps - if the volt is within the range - so like you said - its ok - he told me its 30% of what ever the size battery you are charging -

the charge volts have to stay between 27.6 - 29.2 - then it wont kill the battery any faster - if you charge over 29.2 - he didnt recommend - would shorten the life - and told me - to find one with in the range and you be fine - at 20 amps -

float is between 26.8 - 27.2 - at 20 amps - stay in those ranges and your be fine - this is for the battery i am using - MK 24SLD G -

so this means i am good to try it - its just finding the charger in range - i found this one - http://www.batterystuff.com/battery-cha ... 24-15.html

its 15 amps but its in the range - i just dont understand how i connect it - ? i may have to call the company if i can reach them -

if you know any other chargers i can look at - put a link for me -

thanks -
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Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby Burgerman » 06 Jun 2014, 00:38

Much of that is incorrect. I will reply in 15 mins...
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Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby expresso » 20 Jun 2014, 04:22

Would someone know by looking at these pictures - where would i connect my wires for a direct connection to fast charge

here are pictures of my friends chair - this is how the batteries are connected - from these pictures - can someone tell me for sure - where would i connect the wires for a direct connection - ?

i am not 100% sure this is the same way my chair is connected - but i think its the same -
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Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby Burgerman » 20 Jun 2014, 09:19

£3 Voltmeter.

Measure.

Wherever it says 24V on a red and black terminal. That's it.
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Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby Burgerman » 20 Jun 2014, 09:23

The charger you linked to will not charge much faster than a mobility charger. And its a 3 bank charger. Designed for charging up to three non isolated batteries individually. It will not charge at 24v.

The message you got from MK was both incorrect and generic and confused.
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Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby shirley_hkg » 20 Jun 2014, 14:03

;) Image
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