PINNED - AGM & GEL battery info lead battery info

[SWalkusz]

No charger can auto detect.

You need a charger than can do gel properly then any half decent marine charger SHOULD do 14v or 14.1V CV stage, etc.

https://www.batterystuff.com/files/pronauticp.pdf eg...

User Selectable Battery Types from above link:

Flooded 14.8 VDC 13.6 VDC
14.7 VDC 13.4 VDC

Sealed 14.4 VDC 13.6 VDC
14.6 VDC 13.4 VDC

AGM 14.4 VDC 13.4 VDC
14.6 VDC 13.7 VDC

GEL 14.0 VDC 13.7 VDC
14.4 VDC 13.8 VDC

LiFePO4 - Lithium 14.8 VDC 14.4 VDC
14.6 VDC 14.4 VDC

Calcium/Custom Programmable Programmable
VDC* default VDC* default
15.1 VDC 13.6 VDC
13.6 VDC 13.6 VDC

Equalization 15.5 VDC 15.5 VDC

If you charge a gel battery with a typical 14.4V universal charger (as supplied by many powerchair manufacturers) you are charging at .4V too high. And lose around 35% of the cycle life. Worse, this assumes 20C max, but most batteries are charged directly after use, and on a 30C summer day the battery may be at 35C. So you should be at 13.8V absolute max... So you lose 60% of the battery life! And thats what everyone uses!

Thats the one. Perfect, thanks BM.

[Burgerman]

Theres loads. Thats the first I looked at. You have to understand that gel makes up less than 1 percent of the market. So nobody bothers, or understands.

[SWalkusz]

Thanks BM, your original Pro Sport 20 dual recommendation is by far the best value http://productimageserver.com/literatur ... 9493OM.pdf

[SWalkusz]

Thanks BM, your original Pro Sport 20 dual recommendation is by far the best value http://productimageserver.com/literatur ... 9493OM.pdf

http://www.ebay.co.uk/itm/ProMariner-Pr ... 1438.l2649

[Burgerman]

Thats a 10A charger. Its fine for cyclic use, but dont leave connected for say 24 hours or longer. As float is 13.8v.

And you may be surprised how long it takes to charge. Because unlike mobility chargers it will charge properly!

If you need to use it, do so anyway. If you dont need to get up, leave it on for up to 12 or 14 hours.

[SWalkusz]

Another option would be a Battery to Battery charger but use a 12V transformer input.
http://www.ebay.co.uk/itm/like/19229849 ... 527&crdt=0

[Burgerman]

Yes then you end up with a thing that can only charge lead batteries. One at a time. So you will need two of those.

But the charger we use for hobby stuff is way better than that. And can do all that it can do as well.

0 to 40A input. 10 to 30V input.

And output is
10mA to 40Amps.
1v to 35V
Any chemistry.
And any termination current, delta peak, cc finish, etc.
And does all lithium chemistries, inc balancing etc and discharge testing.


Will charge everything from a watch battery to a full sized EV.

[SWalkusz]

Yes then you end up with a thing that can only charge lead batteries. One at a time. So you will need two of those.

But the charger we use for hobby stuff is way better than that. And can do all that it can do as well.

0 to 40A input. 10 to 30V input.

And output is
10mA to 40Amps.
1v to 35V
Any chemistry.
And any termination current, delta peak, cc finish, etc.
And does all lithium chemistries, inc balancing etc and discharge testing.


Will charge everything from a watch battery to a full sized EV.

Yes, but I don't want to spend any more than £200. And do want US standard Gel + Odyssey/Optima AGM multi stage profiles.

[Burgerman]

180 uk pounds.
Did I mention it has free PC control, configure, discharge, and graphing of all this and cell balancing? And it works from a 12 or 24v battery like in your car? Or a power supply, big or small?

I have one on my passenger seat. I charge my lithium chair as I drive. Then at the flying field, I charge my planes and quad copter from my powerchair...

[SWalkusz]

What I might try as I already have a couple of good travelling type solar charging panels and battery bank that needs a purpose to implement them.
Wow, to the above, BM. Do you find the Hobby Charger makes everything else redundant? Can it be used to rebalance the Gel batteries as per my original intention?

[Burgerman]

What wattage?

[SWalkusz]

What wattage?

40W. They were intend to charge my laptop off the grid.

[Burgerman]

Well I have a lot of solar around here.

The only time you will get 40w is if they are aimed exactly at the sun, clear sky, and at 12 noon, if the panels are cool or just rained on. In summer.

All the rest of the time you will get less. Usually a lot less. Today, my 3000 watt solar array, peaked at 1660 watts, for around 10 secs. Most of the daylight hours they were much, much lower. And its early September.

So I wouldn't count of that working very well. It may, in summer. As long as you allow a couple of hours and angle them correctly.

For eg. My van has a high quality 50 watt panel laid flat at zero degrees on its roof. Its connected to a charge controller to keep my van battery topped up when not used. It struggles to cope in winter, and just about keeps up. In summer its at least 10 or 15x more powerful than required. But the charge controller stops it exceeding 13.3V once fully charged. So safe. And this is without running a laptop.

[SWalkusz]

Have you tried any of the Exide AGM batteries? Exide Edge FP-AGM24DP for example.

[SWalkusz]

Have you tried any of the Exide AGM batteries? Exide Edge FP-AGM24DP for example.

Or Lucas Gel/AGM

[Burgerman]

Exide Edge FP-AGM24DP for example

Cant find full specs. But it looks like a reasonable starter battery (a few CA behind the Odyssey however at 770 instead of over 1000) so it will propel a chair almost as well, but no amount of searching brings up any proper specs. And no mention of cycle life capability in traction (80% DOD) use. So it might be OK or crap... We cannot know.

Or Lucas Gel/AGM

Run away!

When looking at batteries look at mOhms. If non are shown they are likely rubbish! So:
Then look at CA (Cranking Amps). As an example of good, the Odyssey 68Ah GRP34 for eg is well over 1000 CA. It has a 135 minute reserve capacity which bodes well in a typical powerchair too. Internal resistance is just 2.5mOhm which means it can give double the current at the same voltage drop as a 5mOhm battery so is extremely important! It also means faster charge, lower peukert (greater usable capacity at high discharge rates etc). And that it charges much more completely in a limited time. Because of lower peukert the odyssey 68Ah may give better range than the 73Ah MK for eg.

Lastly, look at Cycle life at 80% DOD. Odyssey claim 400. (MK gel are worse specs everywhere else, but claim 500). In reality both give the same because its far harder and slower to charge a gel properly overnight. The odyssey is a little lighter too being 1 inch lower, and group 34.

Once you understand the parameters, you will soon see that Odyssey for fast charge, performance, better torque, sport, faster chairs. And MK gel (NOT AGM!) for longest life and reasonable performance (and harder to find Sonnenschein gel) are the only real contenders.

[Burgerman]

Occasionally you can get an odyssey under a re branded name cheaper like this http://www.impactbattery.com/nsb-agm-34-78.html

http://cdn.impactbattery.com/media/down ... _34-78.pdf

[SWalkusz]

Occasionally you can get an odyssey under a re branded name cheaper like this http://www.impactbattery.com/nsb-agm-34-78.html

http://cdn.impactbattery.com/media/down ... _34-78.pdf

http://www.batterymegastore.co.uk/marin ... e-072.html

[Burgerman]

Bought 2 real odyssey here VAT free a few months back for a friend.

https://www.devon4x4.com/odyssey-pc1500 ... n-top.html

[SWalkusz]

Bought 2 real odyssey here VAT free a few months back for a friend.

https://www.devon4x4.com/odyssey-pc1500 ... n-top.html

Tayna has them £246.95
https://www.tayna.co.uk/ODYSSEY-PC1500D ... P7671.html

[Burgerman]

Yes but they no longer offer us 20 percent VAT off. Thats about £50 lower per battery!

[Burgerman]

The other thing is this.

Lets say you pay 250 each = £500.
You could pay $1000 for a lithium battery instead.

Lets compare the two deals.
Lead will give you 68Ah and around 40 of that is actually usable. Giving you say 15 miles range (initially), falling to 10 after say 18 months and then you replace.
So 500 div by 18 months = £27.77 per month for an average of 12.5m range.

Lithium, for £1000 gives you 120Ah of which ALL is usable. Instead of 15 miles range you now have 45 miles. 3x better!
Instead of the odyssey 400 cycles (18 months or less charged nightly) you get either 10s of thousands of cycles if you only go 15 miles. And you can charge every 2 days and yet still only use 66% discharge level. So get at least 8k charges. Thats probably going to outlive that chair, (and you). So we say a nominal 10 years plus for easy numbers.
So with lithium, you get 3x the range, all for less than one third the cost at £8.30 per month...

The realty is even better. Because even if you lost HALF the range, at say 15 years, thats still got much more than a set of brand new lead bricks! So if this is OK, then you probably keep going and its down to around £5.80 per month.

Nobody can afford lead. It performs crap. And works out 3 to 5 times more expensive with rubbish range!

[SWalkusz]

The other thing is this.

Lets say you pay 250 each = £500.
You could pay $1000 for a lithium battery instead.

Lets compare the two deals.
Lead will give you 68Ah and around 40 of that is actually usable. Giving you say 15 miles range (initially), falling to 10 after say 18 months and then you replace.
So 500 div by 18 months = £27.77 per month for an average of 12.5m range.

Lithium, for £1000 gives you 120Ah of which ALL is usable. Instead of 15 miles range you now have 45 miles. 3x better!
Instead of the odyssey 400 cycles (18 months or less charged nightly) you get either 10s of thousands of cycles if you only go 15 miles. And you can charge every 2 days and yet still only use 66% discharge level. So get at least 8k charges. Thats probably going to outlive that chair, (and you). So we say a nominal 10 years plus for easy numbers.
So with lithium, you get 3x the range, all for less than one third the cost at £8.30 per month...

The realty is even better. Because even if you lost HALF the range, at say 15 years, thats still got much more than a set of brand new lead bricks! So if this is OK, then you probably keep going and its down to around £5.80 per month.

Nobody can afford lead. It performs crap. And works out 3 to 5 times more expensive with rubbish range!

All I can find ready made is
http://www.rothervalleyoptics.co.uk/BP2564.html
https://www.amazon.co.uk/LiFePO4-LITHIU ... B01BDPZ9F6

[SWalkusz]

also
http://www.golfworkshop.co.uk/Lithium_M ... y_24v_48AH
http://www.alpha-batteries.co.uk/12v-50 ... m-battery/

[SWalkusz]

https://www.batterymasters.co.uk/sealed ... luded.html
https://www.a4wproducts.co.uk/mobility-batteries/

[Burgerman]

All those have the exact same issues as all the ready to go bricks. And are a waste of money.

Except the headway one that is too small Ah, and we are already doint those better here without the daft BMS issues, and with 90 to 120Ah! For a lot less £££. All they have done is copied what we do on here for nearly a decade, but made a smaller one. And instead of charging properly are relying on the typical BMS which is the source of all the lithium problems and shorter lifespan. And added their markup. You can do that yourself cheaper by ordering from say www.evassemble.com.

Theres are many lithium conversions, ready to go swap bricks that will "work". Thats easy. But finding one thats reliable, that will give the real benefits that lithium offers is not. None of these ready to fit BMS equiped smaller sized ones will do this. You are throwing money at something that at best will only give marginal range improvement and not last as long as it should and may be unreliable and cause problems. This is of course your choice. But I have looked at all this before. And thats why I dont use any of those options!

Read the lithium thread here, because you are going over all the stuff already discussed to death for years!
viewtopic.php?f=2&t=1813

[SWalkusz]

Sonnenschein/Dryfit (German) and Deka Gel-Tech (US)

Charging.Sonnenschein/Dryfit (German) A200 product is correctly charged (@ 2.4v/cell)14.4v/ and float voltage is (2.3v/cell)13.8v) @ 20°C to 30°C. US (Deka Gel-tech) is correctly charged at (2.35v/cell)14.1v with (2.3v/cell) 13.8v float @ (68°F) 20°C.
For lower and higher temperatures, from (minus) -22ºF up to (plus) +120ºF, charge voltages should be adjusted according to the graph supplied with each battery. (A 500.)

[SWalkusz]

The Sonnenschein GF-Y Exide technologies (A-500) are Euro standard charging 14.4V (10-30 degrees C)

[Burgerman]

True. Some newer sonnenschein claim to use a different mix of pasted material that is more tolerant and may not damage gel at 14.4V. (gasses at higher voltage). But be careful because battery manufacturers claim this to allow a battery to comply with a standardised harge system, and so sell more too. So it may be a marketing change only! Plus its not possible for one voltage to cover a 10 to 30 degrees range! Its just sell sheet marketing.

So are MK sold as 14.4V compatible. You can, it will work, its compliant, and its safe (ish).

But that isnt the full story. They CAN be charged at 14.4V. (or 15V!) Provided you dont care about losing approx half the cycle life. At £500 a set I would think it matters. MK and Sonnenschein are exactly the same. Sonnenschein developed the system of starved gelled electrolyte, and exact pasted lead dioxide chemical paste mix/grid etc. They licenced it to MK who are a bigger manufacturer in the US. Both are identical in tech details originally.


The CORRECT voltage for max cycle life in both cases (13.80 to 14.1MAX at 20C) So idealised 13.95V.

All of that info is available on the tech sheets from both Sonnenschein and MK. I no longer have the sonnenchein data online, but retained the MK ones here. I have the others on my PC.

Heres the MK tech charge data sheet.
http://www.wheelchairdriver.com/MK1.pdf ACTUAL MK CHARGE DATA IF YOU CAN FIND ANY CHARGER TO DO THIS.

http://www.wheelchairdriver.com/MK2.pdf AGM and Gel compared, tech data. Note the CHART D showing 60% loss of cycles at 0.7V too high charge voltage. And 22% loss at just .4v too high...
Also note correct charge voltage for gel at 20C. And then remember that after use on a 30C day the battery may be 35C so the correct charge voltage is much lower than this still! See: Gel Charge and Float Voltages at Various Temperature Ranges, on page 11.

http://www.wheelchairdriver.com/MK2.pdf Note charge voltage MAXIMUM and warranty void if ignored... On these three.
http://www.wheelchairdriver.com/MK2.pdf
http://www.wheelchairdriver.com/MK2.pdf

[Burgerman]

I am not sure that I would charge the Sonnenschein at 14.4 though. If you try that, the current never drops to the 1000thC point, and in fact begins to rise again. A sign of thermal runaway. At least on an older set I have here. So while it may be compliant, I am not sure its wise. If you charge at 14.1 they end charge normally.