PINNED - AGM & GEL battery info lead battery info

Power wheelchair board for REAL info!

POWERCHAIR MENU! www.wheelchairdriver.com/powerchair-stuff.htm

Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby Burgerman » 14 Feb 2014, 11:26

Yes you can connect any size battery to any other. But better not to mix types although I have in the past.

TOTAL capacity is all that matters. But then you have size and weight issues.

In my workshop there are 16 batteries. New(er) and old, from 6Ah to 100Ah.From powerchairs and vehicles, and UPS systems. All connected in parallel and charged as 1 big battery old battery. If we have a power cut, they will run a 2kw inverter and my gas heating boiler will work so I will have heat and hot water too, electric bed, lights, freezer and powerchair chargers will work. Don't throw out old batteries! Connect all together, and pile them up. Charge at 13.3v forever.

A full battery is 12.9 to13.1v.
A 12.5V battery is about 50 percent.
A dead battery is 12v.

If all are connected together they are all the SAME voltage.
User avatar
Burgerman
Site Admin
 
Posts: 65050
Joined: 27 May 2008, 21:24
Location: United Kingdom

Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby bgmen » 20 Mar 2014, 15:55

GF12 51Y these batteries how to properly load?
before you put batteries in a wheelchair should they be charged equally?
bgmen
 
Posts: 364
Joined: 25 Sep 2013, 18:21
Location: bulgaria

Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby Burgerman » 20 Mar 2014, 18:02

Yes, charge each one with a 12v 3 stage modern charger.
Or connect together overnight so both end up at the exact same state of charge.

Then fit and charge as normal.
User avatar
Burgerman
Site Admin
 
Posts: 65050
Joined: 27 May 2008, 21:24
Location: United Kingdom

Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby bgmen » 21 Mar 2014, 10:20

with car charger to charge separately to 13volta.
as I put the batteries in the wheelchair when to recharge them when he was 3 red
bgmen
 
Posts: 364
Joined: 25 Sep 2013, 18:21
Location: bulgaria

Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby Burgerman » 21 Mar 2014, 12:43

?
User avatar
Burgerman
Site Admin
 
Posts: 65050
Joined: 27 May 2008, 21:24
Location: United Kingdom

Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby bgmen » 21 Mar 2014, 13:46

battery should initially load them equally 13v
bgmen
 
Posts: 364
Joined: 25 Sep 2013, 18:21
Location: bulgaria

Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby Burgerman » 21 Mar 2014, 14:12

A battery should be fully charged at 14.4v AGM or 14.1v GEL, and then left on float for approx. 5 hours at 13.6 volts.
Then it will read 13 to 13.3 volts after charge.
About 2 days later this will have fallen to 12.9v on most AGM batteries or 13.1v on Gel batteries.

It does not matter about the above, provided both batteries read the same. Both at 12.73v? Both are 12.50v? Both are 13.1v? All good. Fit and charge as normal.

If they are DIFFERENT then connect them together in parallel and leave them a day. Or fully charge.
User avatar
Burgerman
Site Admin
 
Posts: 65050
Joined: 27 May 2008, 21:24
Location: United Kingdom

Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby bgmen » 21 Mar 2014, 15:17

after fully charge the battery, leave them more 5h of 13.6 volts
bgmen
 
Posts: 364
Joined: 25 Sep 2013, 18:21
Location: bulgaria

Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby LROBBINS » 21 Mar 2014, 16:12

as I put the batteries in the wheelchair when to recharge them when he was 3 red


NO! Re-charge them as full as possible as often as possible. Every night, all night even if you have used it very little. During the day too if you're not driving it. The more time the battery stays full, the longer it will last. LEAVING IT EMPTY, OR EVEN PARTIALLY DRAINED, DESTROYS LEAD ACID BATTERIES.

Ciao,
Lenny
LROBBINS
 
Posts: 5543
Joined: 27 Aug 2010, 09:36
Location: Siena, Italy

Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby bgmen » 06 Apr 2014, 16:04

before loading them to 14.1 batteries have to exhaust them
bgmen
 
Posts: 364
Joined: 25 Sep 2013, 18:21
Location: bulgaria

Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby Burgerman » 06 Apr 2014, 17:12

NO.

NO.

NO!!!

NEVER EVER exhaust them. It DESTROYS them.

ALWAYS keep charged as much as possible, as often as possible.

Charge Every Day (overnight), if you used it at all, no matter how little.

Charge once every 2 weeks even if you NEVER use it at all.

Never discharge it more than needed. Charge several times a day if you want!

Charge a lot, often, at any opportunity while you eat or check email, and always FULLY overnight.
User avatar
Burgerman
Site Admin
 
Posts: 65050
Joined: 27 May 2008, 21:24
Location: United Kingdom

Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby LROBBINS » 07 Apr 2014, 08:48

If what you are thinking is that you have to exhaust the (lead-based of any type) batteries before re-charging - NO! NO! NO! NO! NO! All that does is sell batteries because it KILLS them. Charge as often as possible even if you've hardly used it at all. Ciao, Lenny

P.S. One example. Years ago a parent told me of getting that advice from a dealer - she wondered why the battery wouldn't hold a charge after only two months of this abuse. DON'T DO THAT.
LROBBINS
 
Posts: 5543
Joined: 27 Aug 2010, 09:36
Location: Siena, Italy

Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby LROBBINS » 07 Apr 2014, 08:50

John (Burgerman) and I were writing at the same time, but you can see from our almost identical messages just how seriously we take this. Ciao, Lenny
LROBBINS
 
Posts: 5543
Joined: 27 Aug 2010, 09:36
Location: Siena, Italy

Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby Burgerman » 07 Apr 2014, 13:00

Heard a salesman telling this "run it till its dead before charging".
And, "it will develop a memory if you don't run it right down", bullshit yet again in response to: "my scooter has no range" in a mobility shop in the town centre a week ago.

The guy was saying this because he was told this was correct by their own TECH guy in the back!

Seriously this myth stems from the so called Ni-Cad battery memory effect. And even THIS is also a myth, One that grows and grows. There are people claiming its to do with crystal sizes etc. Its all crap! It originally happened when a bunch of cells were cycled in orbit on a satellite without getting a full charge by NASA. And was widely reported. So the cells get out of balance, reducing overall PACK capacity, until a FULL LONG SLOW recharge dragged up the low cells. Or by decreased capacity from overcharge.

The Ni-Cad "memory" effect is largely a myth blown far out of proportion. The original source of the battery discharge retention cycle was discovered in early satellites which were charged with solar power. Early in orbit, the batteries were discharged at a constant rate, then recharged for a relatively specific period of time. As the cells were discharged from their original 1.6V output down to about 15% capacity, they were charged for exactly the same amount of time each orbit due to the period of time the solar panels hit the solar blanket of light.


It NEVER was real, it never related to lead batteries anyway...

http://www.repairfaq.org/ELE/F_NiCd_Battery.html This guy says it "is" but then explains that its not real anyway!
User avatar
Burgerman
Site Admin
 
Posts: 65050
Joined: 27 May 2008, 21:24
Location: United Kingdom

Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby bgmen » 07 Apr 2014, 18:04

is there a charger that is wheelchair and loaded to 14v?
bgmen
 
Posts: 364
Joined: 25 Sep 2013, 18:21
Location: bulgaria

Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby Burgerman » 07 Apr 2014, 20:18

I honestly don't know how to reply.

Try some different translation software?

If you have GEL batteries, you need to charge them at 14.10V at room temperature, and until you see 100C to 400C. Or for about 10 hours+ ideally.
If you have AGM batteries you need to charge them at 14.40V at room temperature, and same as above...

But of course you need to DOUBLE this in a wheelchair. So GEL 28.20V and AGM 28.80V.
User avatar
Burgerman
Site Admin
 
Posts: 65050
Joined: 27 May 2008, 21:24
Location: United Kingdom

Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby bgmen » 08 Apr 2014, 08:10

I have gel batteries must be charged to 14.1 charger of my wheelchair charge to 13
bgmen
 
Posts: 364
Joined: 25 Sep 2013, 18:21
Location: bulgaria

Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby Burgerman » 08 Apr 2014, 09:19

No it doesn't.

It charges AT 14.1 GEL or 14.4 volts AGM.

AFTER charge ENDS it drops to 13.5v while on and still connected.
And if you disconnect charger, battery voltage drops to about 13v.
User avatar
Burgerman
Site Admin
 
Posts: 65050
Joined: 27 May 2008, 21:24
Location: United Kingdom

Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby bgmen » 08 Apr 2014, 09:43

charger stops charging at 13.
bgmen
 
Posts: 364
Joined: 25 Sep 2013, 18:21
Location: bulgaria

Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby Burgerman » 08 Apr 2014, 10:03

You monitor this on each separate battery? Because it should charge to 28.2v or 28.6v. AS it charges?

If not then its either already charged. And goes straight to 13.5v or 27v. Or its failty and you should get a properly working charger.
User avatar
Burgerman
Site Admin
 
Posts: 65050
Joined: 27 May 2008, 21:24
Location: United Kingdom

Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby maker102 » 16 May 2014, 21:07

Perfect timing for this topic. I am in need of replacing a set of Group 24 batteries however when I did a search for pc1500 batteries I came up with this on Amazon:
http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=PC1500%20Odyssey%20battery
Kind of dense here, but which one is correct?
maker102
 
Posts: 73
Joined: 18 Mar 2013, 02:58
Location: Illinois

Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby Blade Runner » 16 May 2014, 21:11

I think the T is top terminal and thr DT is dual terminal, both top and side.
Top is what you need.

Bob
Blade Runner
 
Posts: 274
Joined: 14 Jun 2010, 18:13
Location: Spokane Washington

Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby Burgerman » 17 May 2014, 01:19

http://www.batterymegastore.co.uk/produ ... wgody0oA_Q

This is top only. And as cheap as you will get. It doesn't matter if you get dual, single, marine or whatever they are all basically the same. Any that is cheap will work.
User avatar
Burgerman
Site Admin
 
Posts: 65050
Joined: 27 May 2008, 21:24
Location: United Kingdom

Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby ex-Gooserider » 20 May 2014, 04:44

Burgerman wrote:http://www.batterymegastore.co.uk/product/34-PC1500/?ref=bmuk&gclid=CN2f9PnWsb4CFYLnwgody0oA_Q

This is top only. And as cheap as you will get. It doesn't matter if you get dual, single, marine or whatever they are all basically the same. Any that is cheap will work.


Given that Maker102 is in IL, USA, I doubt that a UK vendor would be a good source but otherwise good info...

IIRC what has been said elsewhere, top or top and side terminal configurations will work for most chairs. Side terminal only can be problematic because room is needed for the connections. Also be sure that if side terminals are present, that the battery box is either made from non-conductive material, or that the terminals are totally protected from contacting the box or each other!

It is slightly easier to connect to tab or screw terminals (often labeled "marine"), but since it is easy and cheap to get the adapters to convert automotive post terminals to screw types, I wouldn't spend much extra to get marine terminals...

Given that batteries are heavy, make sure when price shopping to look at prices with both shipping and any sales tax included...

ex-Gooserider
User avatar
ex-Gooserider
 
Posts: 5962
Joined: 15 Feb 2011, 06:17
Location: Billerica, MA. USA

Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby paulgato » 28 May 2014, 23:26

Hi, I have just bought an Odyssey battery and the manual says I MUST use a charger of AT LEAST 0.4C, or 40% of the 10-hour Ah rating, which for the PC1220, with its 10-hour rated capacity of 65Ah means a minimum 26A charger. I phoned Enersys tech. support and got conflicting stories on whether this is really necessary or not. The manual also says 14.7v is the best charge voltage to aim for, whereas BOTH Enersys tech support guys I spoke to said 14.4v would probably be better.

I am thoroughtly confused. Just to recap...

1. Manual says MUST use charger of AT LEAST 0.4C (minimum of 26A in my case) and a bulk charge voltage of 14.4v - 15.0v, with 14,7v being optimum.

2. Tech Support guy A says, "Yes, 0.4C minimum - no one knows why, but it seems it's needed in order to get stated number of cycles. 14.4v is better than 14.7v though."

3. Tech Support guy B says, "No, 0.4C is not required, but a FULL 100% charge IS required, so with a 10A charger (like the one I've already got) that's 11 hours for a fully discharged PC1220 to take it to 95% charged, PLUS another 6-8 hours on float to bring it to 100% charged. That's easier to achieve with a faster charger but a faster charger is not required. 14.4v is better than 14.7v."

4. The top expert at Sterling Chargers says, "0.4C is 'rubbish'. (That's not the actual word he used.) You CAN charge that fast but it will shorten the life of any sealed lead-acid battery, regardless of its particular mode of construction, as you will lose water and sealed batteries can't be topped up. For sealed batteries the slower the charger the better. 0.1C is about optimum. And 14.7v is too high. You need to aim for 14.4v."

So, some say you MUST use a high charge rate, some say you SHOULD ideally but it's not necessary, and some say you SHOULD NOT. And everyone EXCEPT the writers of the manual says 14.4v is better than 14.7v. I am thoroughly confused.

I wonder, with your experience of using and charging Odyssey batteries on a daily basis, what would you say is the best way to charge them, and can you shed any light on why there should be this confusion?
paulgato
 
Posts: 27
Joined: 28 May 2014, 22:57

Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby Burgerman » 29 May 2014, 00:30

1. Manual says MUST use charger of AT LEAST 0.4C (minimum of 26A in my case) and a bulk charge voltage of 14.4v - 15.0v, with 14,7v being optimum.

Yes, 14.4v to 14.7v preferred.
The reason they say you need a big powerful charger is simply because it typically takes a VERY long time to fully recharge a lead based battery. Most mobility chargers are about 7 amps. Most chargers also stop charging way before the battery is truly full.

That means that if a 70Ah battery was charged at 7 amps for a whole 10 hours, it still wouldn't be fully recharged. As some is lost due to heat and internal charging (recombination) losses. And the charger typically charges at full power for only about half of that time then gradually slows down more and more towards the end.

You can rush the first part (big high Amp charger) but the last part takes about 5 hours whatever you do. The reason this is a problem is because your charger will say "ready" long before the battery is REALLY fully charged. If it isn't FULL to 100 percent it gradually sulfates over time and then it goes in the bin. This doesn't only apply to Odyssey batteries but to ALL lead based batteries.

2. Tech Support guy A says, "Yes, 0.4C minimum - no one knows why, but it seems it's needed in order to get stated number of cycles. 14.4v is better than 14.7v though."

He's not a tech guy then. He's an idiot. The reason is the one I gave above and the 14.7v at room temp helps it charge faster, and balance the cells up quickly, while not producing enough hydrogen and oxygen that they cannot be recombined into water. It aids faster charging and doesn't lose electrolyte. If you have enough time, you can charge at 14.4v to 1000thC and get the same number of cycles at only 1 amp! But at 7 amps (typical mobility charger) it takes more than overnight.

3. Tech Support guy B says, "No, 0.4C is not required, but a FULL 100% charge IS required, so with a 10A charger (like the one I've already got) that's 11 hours for a fully discharged PC1220 to take it to 95% charged, PLUS another 6-8 hours on float to bring it to 100% charged. That's easier to achieve with a faster charger but a faster charger is not required. 14.4v is better than 14.7v."

That's the first time I saw a tech guy get it correct. And exactly what I said above.

4. The top expert at Sterling Chargers says, "0.4C is 'rubbish'. (That's not the actual word he used.) You CAN charge that fast but it will shorten the life of any sealed lead-acid battery, regardless of its particular mode of construction, as you will lose water and sealed batteries can't be topped up. For sealed batteries the slower the charger the better. 0.1C is about optimum. And 14.7v is too high. You need to aim for 14.4v."

It doesn't shorten life. It extends it simply because it allows you to get a more complete charge in the shortest overnight period. It gets the BULK phase over faster, leaving more time for the CV stage and float to complete. If you charge slower, and wait long enough, same thing...

And the higher the voltage the more the battery tries to produce gas. Pure lead batteries start to do this at above 14.7v at room temperature, but they are recombinant. This means they turn the gases back into water. Up to point. All carefully tested. Stay below 14.7v and you will not lose any electrolyte. That's the reason they say charge at 14.7... Ideally. 14.4v works too, will add around 15 percent to charge time.


So, some say you MUST use a high charge rate, some say you SHOULD ideally but it's not necessary, and some say you SHOULD NOT. And everyone EXCEPT the writers of the manual says 14.4v is better than 14.7v. I am thoroughly confused.


I wonder, with your experience of using and charging Odyssey batteries on a daily basis, what would you say is the best way to charge them, and can you shed any light on why there should be this confusion?

No confusion at all. I used to sell these, and know a lot about batteries generally, charging, and advised manufacturers on such stuff. The only misunderstanding is that nobody listens!

When you DISCHARGE a battery the acid turns to lead Sulfate. And lead dioxide. And coats the plates. When you recharge COMPLETELY, this is returned to the acid. If you don't it turns to hard large crystals over time, that can never be returned to acid no matter what. And your battery is toast.

For what its worth I charge mine at up to 100Amps as I drive, and at 44A (from my maxed out bench power supply) at 14.7v (29.4 actually) as I type sat here! And all night long at 20A and 14.7v in parallel.
User avatar
Burgerman
Site Admin
 
Posts: 65050
Joined: 27 May 2008, 21:24
Location: United Kingdom

Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby Burgerman » 29 May 2014, 01:33

Simple Odyssey charge info. At 20 Centigrade.

Charge with a 3 stage charger.
STAGE 1 - CC stage ANY current, no limit, up to the 14.4v to 14.7v point. This may be hundreds of Amps, or 1A if that's all you have available. No damage will occur, its just faster or slower. Odyssey have extremely low internal resistance and so will barely get warm at ANY charge rate. Nor will they lose any electrolyte. You only get electrolyte loss if overcharged. If you never exceed 14.7 this cannot happen. The more Amps your charger the shorter this stage lasts.

STAGE 2 - CV STAGE, is where 14.7v has been reached at the max charger amps, and it now naturally falls, away gradually while holding battery at exactly 14.4V to 14.7V. Eventually this will fall to a very low level. You can continue this until 1000thC point is reached and just stop at which point its truly 100% full (fastest method), or you can do what most chargers do, and stop at 100thC (And they all say DONE, but its really not) and then go to float at a lower voltage (below).

STAGE 3 - FLOAT STAGE. For CYCLIC use float at fixed 13.5 to 13.8V, as this completes the charge in about 4 to 6 hours on a healthy battery. Current is very low at this point. You have most likely started using the powerchair after the green "charged" light came on at the end of the STAGE 2 above... So many batteries do not get completely charged. For LONG TERM storage float, use 13.3v to 13.4V Indefinitely.
User avatar
Burgerman
Site Admin
 
Posts: 65050
Joined: 27 May 2008, 21:24
Location: United Kingdom

Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby paulgato » 29 May 2014, 03:02

Aha! That's really useful information. (Just seen your second post too.) So Tech Guy B at Enersys was right then. That's good news.

Tech Guy B said that from a charging point of view the Odyssey batteries are identical to the industrial/telecom SBS battery range, on which the Odyssey batteries are based, and for which the Thin Plate Pure Lead technology was originally developed. I had discovered that the tech literature for the SBS batteries gives a minimum recommended charge rate of 0.1C, whereas the tech literature for the Odyssey Extreme batteries gives a minimum of 0.4C. Tech Guy B said the reason for the difference is that they reckon that managers of large battery banks in industrial settings are more knowledgeable, and more able to closely monitor and control the charging regime, whereas ordinary public people using them in devices where they are discharged and recharged daily usually don't appreciate the length of time it takes to get to a 100% charge, nor do they recognise the absolute importance of achieving that 100% charge.

I'm sure to you this is obvious, and now it all makes sense to me too, but to a non-expert like myself, who was getting different stories from supposed experts who were all equally sure of their opinions and who sounded equally plausible as far as I could tell, it has been very confusing, to the point where I was regretting ever getting involved with Odyssey batteries.

I think what I will do is use the CTEK 10A charger for the time being and make sure it is on charge whenever it is not being used, and then try to get hold of a decent charger of 20A-30A rating, which also has a 14.7v setting, once I have worked out where I'm going to put it. The CTEK MXS10 charger I already have has a 14.7v setting, but the CTEK 25A chargers (MXS25 and M300) only have a 14.4v setting, which is why I was looking at the Sterling Power PCU ones, which have a user-adjustable setting as well as loads of factory settings.

I should perhaps say what I'm using this battery for, as I'm not using it in a power chair. It's a project to try to get an average of 100mpg out of the Mk4 VW Golf TDi estate car I use for work. (It's a bet I have with a friend who recently bought a Prius Hybrid. So far I'm at about 82mpg overall average.) Right now I'm engaged in sorting out a permanent system for doing away with the alternator, or rather, only switching it on for very long journies where I can't plug the car in to recharge. I've already killed one cheap AGM 'leisure' battery in about 6 months of alternator-less driving, so I wanted to get the best deep-cycle-capable battery that would fit in the Golf engine bay without modification, and that, I was told, would be the Odyssey PC1220.

(I apologise if this is 'off-topic', but hopefully the parts about Odyssey battery charging will apply equally to power chairs.)

I also have a second battery which feeds power into the main car electrical system via a DC/DC step-up converter, which outputs 12A at a steady 14.0v. 12A covers daytime driving current requirements easily, but at night, or with wipers going, power is drawn from the main starter battery as well. (I can add a second 12A DC/DC converter in parallel if it seems necessary.) Currently I'm just using an old but decent car battery as the 'donor' battery, but once I've done all the taking-the-carpets-up-and-running-wiring and so on, I'll be using either one or two Yuasa YPC100-12 105Ah AGM deep cycle batteries, which will be mounted in the spare wheel well below the load area. One YPC100-12 is already installed there but not wired up yet. I was a bit concerned about the added weight of a second YPC100-12 but I'm leaning now to the view that a nicely comfortable over-supply of lead in the rear will result in a much better and more long-lived system, as then my daily short journies will barely make a dent in that 210Ah bank and the batteries will only be drawn down low on those very occasional longer journies.

I came across your site here, saw that you had been using Odyssey batteries for your daily personal transport, and realised that power chair users probably make roughly the same demands on batteries as I do by driving without an alternator, ...or probably even more. Oh. and yes, I am saving about 10% on fuel by not using an alternator. That's 10% of about £1500/year, so not negligible, although I don't expect to actually save any money with this project! I plug the car in to the mains via a discrete bumper plug whenever the car is on the driveway. I also have an engine pre-heater fed via the same bumper plug, which I switch on with a remote control key fob thing from inside the house an hour before driving off. That also saves about 5% on fuel overall, but more on shorter journies of course.

The reason I was reluctant to get a larger charger than the CTEK 10A one I already have installed in the engine bay is that larger chargers are too bulky to fit there, and/or they have cooling fans so are not waterproof. I would have had to put a larger charger inside the cabin somewhere, drill yet more holes through the firewall for the charger output cables, plus it's hard to find places where larger chargers would fit and get adequate ventilation. I found ONE place in the rear where a 25A CTEK charger for the rear batteries will fit, but nowhere in the front really. So it's good news that I don't absolutely NEED a high current charger for the starter battery and I really appreciate your advice.
paulgato
 
Posts: 27
Joined: 28 May 2014, 22:57

Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby Burgerman » 29 May 2014, 07:44

I presume you have seen the F1 cars this year?

Why not keep the large amp alternator, and use an SSR to disconnect it during engine power, and reconnect it when you need to brake vie a link to the brake light switch. That will take a load of the brakes, take no engine power at all and charge your battery...

And in inertial switch can be used too or instead so that the alternator adds power on overrun or while engine braking.
User avatar
Burgerman
Site Admin
 
Posts: 65050
Joined: 27 May 2008, 21:24
Location: United Kingdom

Re: AGM & GEL BATTERY INFO for POWERCHAIRS

Postby paulgato » 29 May 2014, 13:38

Good thinking Burgerman. If I could do what you suggest, I would. In fact on my list of things to do today is to fit the replacement alternator that has been sitting in a box in my living room the past couple of weeks. I managed to destroy my current alternator by experimenting with regenerative braking. The problem is I don't know enough about alternators.

I successfully disabled the alternator some months ago by disconnecting the wire that goes via the ignition switch and via the dash warning light to the alternator. With that disconnected the alternator won't start up. Switching the alternator back on is easy - just reconnect that wire. However, once that wire has been connected and the engine started, disconnecting it won't stop the alternator as it provides its own field current once it is running. So the difficulty is in switching OFF the alternator once it is running.

I destroyed the alternator by doing the following. I was wanting to fit an ON/OFF switch on the dash for the alternator, but also wanting to be able to connect that switch in with the brake lights, so as to achieve a degree of regenerative braking. (an inertia switch would be better) I had read somewhere that if you softly ground the field current (through a resistor or a light bulb) then that will stop the alternator producing current. I tried that - or thought I was trying that - by grounding the 'IGnition' wire I had disconnected - grounding the end of the wire still attached to the alternator. I tried first with a 5w bulb. Sure enough, the battery voltage slowly dropped from 14.4 volts down to about 13v, but as soon as I disconnected the bulb, it went back up to 14.4v. I then tried a larger bulb (lower resistance). The only other bulb I had was a 55w headlight bulb. That didn't light, and to be honest I don't now remember whether the voltage dropped when it was in circuit, but after I had tried that larger bulb I found the alternator was putting out 14.4v even when the IGnition wire was disconnected and the engine had been off for a while (and then re-started obviously!) I found that even with the engine off and the key out of the ignition, there was now 800mA or so getting into the alternator direct from the battery via the big fat charge wire - energising the field winding 24/7! Presumably I had blown/shorted at least one diode in the alternator. Since that little experiment I have had to disconnect ALL wires from the alternator to prevent it putting out a charge, and to prevent it draining the battery when parked up. (Not raining (much) and no work on, so I should get off the computer and fit that new alternator today.)

So yes, if there is another way to switch the alternator on AND OFF with the engine running, then I am all ears. I had considered a complicated circuit involving a step-up voltage booster, to fool the alternator into thinking the battery voltage was a couple of volts higher than it actually is, but after that little mishap I kind of lost confidence and put the idea on the back burner. How would this Solid State Relay idea work then?

(I am aware this really IS going off-topic now!)

(Someone once suggested putting a couple of NiCad cells inline with the alternator's battery sense wire to up the sensed voltage a couple of volts and stop the alternator putting out, hmmm... Or if I could fit an alternator from the newer Bluemotion Golfs which use renenerative braking, and control that somehow...? Or somehow fit a an electro-mechanical clutch so the alternanator doesn't even spin when it's not needed...?)
paulgato
 
Posts: 27
Joined: 28 May 2014, 22:57

PreviousNext

Return to Everything Powerchair

Who is online

Users browsing this forum: No registered users and 242 guests

 

  eXTReMe Tracker