Please take time to link to my site if It helped!   
Questions or want to share?  Message Board


Updated:  03-Sep-09


Detailed Full PowerChair Related ONLY Menu HERE

Detailed Wheelchair Accessible Vehicles ONLY menu HERE

Detailed Menu of Everything else HERE!

Dodge Grand Caravan

VW Caravelle VR6

My SLIGHTLY Modified Improved Powerchair

Part 1 | 2 | 3 | 4 | 5 | 6

My VERY Modified Off Road & All terrain DO ALL Powerchair!
Part 1 | 2 | 3

What Goes Wrong Power Wheelchairs

Powerchair Tyres

Drive your Powerchair by Radio Control

Powerchairs & Range

Off Road DO ALL Indoor & Outdoor Powerchairs

Off Road ONLY Outdoor Powerchairs & 4x4
Page 1 | 2

Manual or Electric Wheelchair?

Why ALL Powerchairs NEED  to be Off Road Capable!

Choosing  a Suitable Powerchair

Wheelchair Width

Batteries for Both Vans & Power Wheelchairs

Inverters & Chargers

Very flexible charger!

Charging Batteries

Fast Charge Your Power Wheelchair

Which batteries to buy

Dodge Grand Caravan 1

Dodge Grand Caravan 2
Dodge Grand Caravan 3
Dodge Grand Caravan 4

Latest 2008 2009 2010 Disabled Converted Dodge Chrysler And Voyager Minivans
Chrysler Voyager Entervan Diesel

Suzuki Wagon R

More Here

Mercedes Vito - soon!
Kia Sedona - soon!

Modified Disabled Vehicle Insurance

Breakdown Cover

Disabled Adapted Cars


VW Caravelle

Dodge Grand Caravan can be used to transport up to 4 Wheelchair Seated Occupants

Fiat Doblo

Renault Kangoo - soon!
Citroen Berlingo
- soon!
Citroen Dispatch
- soon!
Kia Sedona
- soon!
Volkswagen Sharan
Mercedes Vaneos
Toyota Hiace
Fiat Multiplas
passenger travels in the front)

passenger transfers & drives)




Puncture proof tyres

Run Flat tyres

Tyre Weld Aerosol


Spare Key

Wheelchair Ramps

Small Generator


Control Systems etc
Hand Controls Manual
Hand Controls Electronic
Van / Car Door openers
Van / Car Wheelchair Tie Downs


Used Disabled Equipment for sale

How to lose weight  FAST!

Email about modifying powerchairs

Keep it looking new 1 2

My Accident!

Climate Change

Electric Cars are a Joke!

Disclaimer & About Me

Site Map



John Williamson

Which Batteries to buy? See also:  Inverters and Chargers  &  All about Powerchair and vehicle batteries and  Which batteries to buy or Detailed PowerChair Only Menu   More Charging Methods

I am EXTREMELY heavy on powerchair batteries. Partly because I am very heavy! Partly because I use full size hi end modified powerchairs that place huge demands on batteries anyway, partly because I don't sit at home all day.  I actually use and abuse my powerchairs a lot. It's batteries last between 6 weeks (read later!) and 15 months at very best

All the batteries on this page are the same "size" Group 24" (or 34) and all fit the same powerchair and scooter battery compartments as well as my van and almost all large hi end full range outdoor powerchairs. There are some very unusual battery choices on this page tested purely out of curiosity!  So you don't have to.  If you want the quick answer and have a moderately powerful and "normally" programmed powerchair buy an MK. If you want fast charge capability, more power (torque) in a faster or reprogrammed powerchair that draws a lot of power then you want the Odyssey AGM batteries. Non of the rest are really worth even considering.

I understand batteries and charging systems very well having sold batteries over many years and have tested a good few deep cycle batteries to destruction personally over the last 12 years. Many more of them than you would expect. And have fitted totally unsuitable ones on purpose too just to see what happens as you do!

And its not pretty. I do this both for my own knowledge and so that you sane people don't have to!  I log everything too, (end of day voltage/state of charge, temp, hours use etc) so know what works and why.  With THIS. If you want to KNOW about batteries and are a control freak then get one ASAP!

ABXAGM 70ah Deep Cycle and Starter battery.

Before ever fitting ANY new batteries you really must charge them individually with a decent multi stage charger with the correct finishing voltage for the type of battery.. In the case of these two below, it was especially important as my trusty voltmeter told me that one was 12.3 volts straight out of the box! That's l very low.

The other was at 12.6 volts which is pretty normal and almost fully charged. That was expected. Had I just fitted them, as most normal people would do, then they would be very unbalanced. 12.3 volts equates to a half discharged battery or less. The other one was nearly fully charged.  Continued below...

ABXAGM medium | ABXAGM large

Had I then either used the powerchair with them as they were or plugged the powerchairs charger straight in after fitting, then the batteries would be damaged in both cases. I really wonder how many people do this? If I drove the powerchair the "flatter" battery would get "discharged" far too low while the other was only partly discharged. Deep discharge hurts all lead based batteries. If I had charged it in a "series connection" or string (as it is when fitted in the powerchair or scooter) then I would have overcharged the almost fully charged battery causing damage and gassing of the electrolyte and probably still not have fully charged the half discharged one. Because the charger only sees the TOTAL voltage of both batteries. It has no way to know one is very low. 

In this case here (picture above) I am using my Ctek 8 stage charger (7 amp) to charge two new ABXAGM Deep Cycle and Starter (dual purpose) batteries. I chose the 14.7 volt setting because generally this is correct for all AGM type batteries. 14.4v is OK but 14.7v is usually recommended for AGM type batteries. 14.2V to 14.4 volts is correct for most GEL type batteries that are used in most powerchairs and scooters. So a 14.4v charger (per battery) or a 28.8v charger like the one your scooter or powerchair comes with will safely charge either type of battery.  If not totally matched. It will work fine with both AGM or GEL. If you use AGM batteries however it helps keep all their cells in balance by using a single AGM 14.7V battery charger every month individually on each battery although its not essential.

Get this wrong though and overcharge a GEL battery above its recommended voltage using a AGM charger and get typically HALF its life expectancy!   First I charged each one individually. so both were "fully charged" to begin with. Then I connected them together (in parallel with positive to positive and negative to negative) and left the charger on a maintenance and float charge for a couple of days to make absolutely sure they were both at the same exact 13.3v level of charge on "float" while I was ready to fit them.

These batteries were cheap!  I am testing them to see if they are any good in a powerchair for my purposes. Obviously I (we all) need the Ah (Amp Hours rating) to be as high as possible for best range and because it lowers the average daily discharge level as a percentage and so extends battery longevity.   Put simply the greater the Ah rating the longer they last in theory!  They are Absorbed Glass Mat type batteries (AGM) not Gel (or Gelled Electrolyte) batteries. Good quality Gel batteries (like MK have typically 500 cycles at 80 percent depth of discharge capability under lab conditions. These AGM batteries like most AGM batteries typically do a few less cycles (400) but are better at making the big currents that my own powerchairs demand. Much better. And they charge faster too.

They are supposed to have 400 Cycles at 80 percent Depth Of Discharge. (D.O.D.) And have extremely high CCA (Cold Cranking Amps) so that means they can deliver a lot of current fast!  They can start a truck! That's what I like to see.   Going by the figures alone without testing these they should perform much like the Optima's or Odyssey that I normally use then, only cheaper and with bigger Ah rating...

We will see! I have high hopes for these batteries.  These arrived three days ago so I will update the results for these as soon as I have any comments.  I expect they will not last as long as I would like at this budget price. We will see!  02-March-09 

09 - March 09 Update... After a few days use I sent them back for a refund. They were short of range and of "power" or "amps" with heavy voltage drop under load. They should have been OK so I suspect one of them was faulty. Never got a chance to load test them individually to find out as the carrier came to collect them too fast!  And they are being replaced with a set of MK Gel batteries this week free of charge.  Remember that one was very discharged when it arrived? That one was probably faulty.

Obviously these are (were) the same size as most of the batteries on this page at roughly 260mm x 210mm high x 175mm wide. They fit MANY large powerchairs and scooters. They are sealed and cant spill. The acid is stored in a Glass Mat which also forms the plate separator in the battery. They are recombinant (Turns Oxygen and Hydrogen gasses back to water) like most wheelchair batteries are so provided the correct charging equipment is used (never over 14.7v) then no electrolyte is lost and they cannot be and don't need topping up!  Shame I cant tell you more about these. Will test another set soon.


MK GEL MOBILITY SCOOTER BATTERIES M24-SLDGFTBoth the Sonnenschein (Smaller Group 34) and the MK GEL Group 24 batteries here are fitted by most of the major mobility manufacturers.


This is all most people REALLY need to know. They are the batteries that 90 percent of all scooter and powerchair users should really buy. Both use exactly the same technology. Both are equally good. 

These are, for most people, the Rolls Royce of Deep Cycle batteries.  They both give the maximum number of deep discharge cycles that you will get from any mobility battery.

Not cheap
but the best sensible QUALITY solution for the job.  Both are extremely similar. Both are GEL batteries (Rather than AGM) and sealed and will not gas or spill under normal use. Safe for flying, non spillable.

Both of these high quality batteries will give 1000 cycles at 50 percent depth of discharge, Which is better than the Optima, the Hawker Odyssey and the ABXAGM AGM batteries (top of page) and both give 500 cycles at 80 percent depth of discharge which is again about 15 percent better than AGM type batteries on this page. For the average user on an average Wheelchair or Scooter these really are what you need. Don't be tempted to buy anything cheaper.  That's for mad people like me to try as an interesting experiment. BECAUSE IT DOESN'T USUALLY WORK OUT CHEAPER IN THE END!

Quality Gel batteries like these normally offer better cycle life, AGM batteries offer faster current (Amps) release if all else remains equal.

Only you can know which is better for you through trial and error or previous experience in your specific application.  For 99 percent of powerchairs and users these are the best solution.

However I still manage to kill both of these batteries in 10 to 13 months on average. That's not actually bad considering that I really work batteries hard. You only get around 500 cycles with these if you discharge them by around 80 percent daily and charge them with a correctly matched charger every night.   Most people do not discharge them so heavily though so get longer life.

If you discharge them deeper, take bigger currents out or fail to charge them after every use then you will get less. My average usage is a little heavy and I take big currents out more regularly compared to an average user or average powerchair or scooter.  I have had 3 sets of Sonnenschein and 2 sets of MK batteries in two powerchairs (10 batteries) so far and another set is on order.

Downside? I removed them from my latest powerchair since it will not wheelie with them fitted. They cannot make the large currents I demand from them. This doesn't obviously effect the vast majority of users!

They don't like big currents. 4.0 mOhm (MK) and 6.0 mOhm (Sonnenschein - smaller battery) for both getting MUCH worse as they become discharged. This is typical for these quality GEL type batteries. That's about 50 percent worse than say the smaller 55ah Optima deep cycle batteries or even the cheap one at the top of this page. That means a 50 percent greater voltage drop under heavy load.  Or an inability to get full power on ramps or curbs on SOME powerchairs.

You notice this as a lack of urgency on a steep hill or a lack of steering control accuracy when going full speed (or trying to) up the same hill.  It gets worse as they become more discharged. They seem like they are discharged or a bit "flat" when there is actually a good bit of charge remaining that isn't really "accessible" as such in a hurry.  This isn't noticeable in an average powerchair in average use for the vast majority of users. For most people the superior deep cycle ability of quality GEL batteries like these is what's important and exactly what's required by them.

A modified powerchair like mine here used very hard on sand or hills needs something that can give a lot of amps fast even when partly discharged. These can both do it when brand new (after a week) and fully charged up but long before range or distance (reduced capacity) becomes a problem they lose that "power" needed to lift the front wheels or to climb a curb or very steep ramp. They go "weak" rather than lose much range over time.

What I THINK actually happens is that voids appear in the GEL between the plates and so they go more "high resistance" over time (No longer 4.0 mOhm / 6.0 mOhm but much greater)

Fast charging wont hurt them either according to the MK representative I spoke to. It still needs a full overnight charge as well though as the fast charge during the day doesn't "fully" charge the batteries and the cells can become unbalanced without it as a result. But they still charge much slower than AGM batteries. Even on the same sized charger due to their higher resistance.

The above information (don't like big currents) is why I personally usually choose a lower cycle life and a dual purpose Starter/Deep Cycle battery now like the Optima, Hawker Odyssey or even the cheap ABXAGM battery at the top of this page..  I prefer to sacrifice cycle life on purpose for wheelie "power" on demand and steep ramp performance even when pretty well discharged.  Stuff the last few weeks and give me some power!!!

I also use the same AGM Deep Cycle and Starter batteries in my van because while they are mainly used as starter batteries they are regularly discharged by the ramp and power doors and suspension system too. They too get deep cycled as well!  Normal factory fitted starter batteries don't like this treatment.

In a stock powerchair with a normal user with standard gearing and programming you don't need to worry about any of this. Just buy either of these two batteries and chill.  Don't be tempted by cheaper batteries because you generally do get what you pay for here.  All the cheap ones have failed me one way or another!

www.sonnenschein.org/A500.htm  and  www.mkbattery.com/hmemobility_products.php


YellowTop S-4,2LOptima Deep Cycle Yellow Top, and Deep Cycle Marine Blue Top batteries. 
Optima batteries are slightly different in that the lead plates are coiled up like a small Ni-Cad battery or a capacitor. They are still AGM type lead acid batteries though. The Blue Marine batteries and the Yellow "deep Cycle" batteries are exactly the same as each other electrically. The only difference is that these two marine ones on my bed have some extra terminals. That's very useful to connect the powerchairs cables to.


Either Blue (deep cycle & Starting) or Yellow 55ah Deep Cycle & Starting batteries are therefore suitable for a powerchair.   They do not make group 24 batteries and these are Group 34 (smaller) sized. As with most AGM type batteries they can make really big currents. Bigger than most of the rest. More even than almost all similar sized or bigger batteries including starting only batteries!  Wheelies and ramps are no problem.  They will however probably not give an average user as many Cycles as the MK or Sonnenschein batteries above. And they are expensive. They actually last longer in my powerchair though than the other Gel batteries because I take too much current from them. Too many amps. 

So figures alone don't tell the full story.  These should be charged to 14.4 to 14.7 volts. Most wheelchair chargers will be fine, and most actually overcharge the standard GEL type batteries to a small degree which shortens their life in the interests of a faster charge. In this way you may be surprised how long these last!  They are shorter, and smaller than most of the other batteries on this page too.

I typically get 14 to 16 months from a set of these. That's better than I get out of the Gel MK batteries which goes against conventional wisdom. These should be about 20 percent worse on cycle life.  Unless you need big currents (8mph powerchair, 20 stone weight, live in a hilly area), then the Gel MK or Sonnenschein batteries are still a better bet. Personally though I love them.


Elecsol batteries looked like a cheap solution too!  So I had to test them so you don't have to! Now first of all they are NOT sealed and contain loose liquid acid. These are not really "mobility" batteries. But they don't know that do they...

They can gas when charged and so may need occasional topping up with distilled water. Depending on charge voltage. They cannot be transported on aircraft either. Standard powerchair chargers are fine. They do have one large redeeming feature however. They are 100ah in the same sized package as all the rest of the 55 to 73 amp ones here on this page. The rest are 55, 56, 65, 70, 73, Amp Hours. (But there's much more to batteries than storage capacity). Woohoo!  More THEORETICAL range, cheap, and Very Deep Cycle! They use carbon fibre plates.

They don't sulphate if discharged apparently (CLAIMED) They can do 1000 cycles according to their website at 50 percent. So then what's the problem?  Yes there had to be one...  No wheelies, no steep ramps because although they claim, to be engine start capable and so should be able to easily zap a powerchair into life they just aren't!   To be fair I expected as much. They are about as good as the MK batteries for current, and are "bigger" capacity so should give more range and longer service life cheaply.

All that happens if you gun your powerchair is that it accelerates moderately and the lights dim on the battery meter!  Well on my chair at least. Then as speed gathers its fine. Actually on my powerchair that's exactly what MK batteries do as well. But they are not for me. On a more average soggy programmed chair they could well be OK but I cant say since I don't have one.

So they "should" be OK on a more "normal" users moderately programmed powerchair with say a 50 to 80 amp controller. I don't know for sure because I don't have a soggy underpowered chair to test them on.  If you need more range and you have a moderate requirement for power with smaller powerchair, 4mph, soft programming so that you seldom actually use the full amp capability then they should be just fine and a bargain. Just watch the battery acid levels.


Hawker Odyssey,  Sold as a Deep Cycle and Starter battery.


Basically they are EXTREMELY good quality AGM batteries and are as good as the Optima's and very similar electrically but larger capacity than the optima. The case is the same size as a group 24 battery but its not as tall. Its a Group 34 battery.

These are 68 amp hour and can be deep cycled or can easily start a truck if you wish. Lasted me 11 months (slightly less than the GEL batteries but with better performance when discharged a good bit) but had power to spare when needed for my modified and reprogrammed powerchair. (Update! They were refitted out of interest and to test and are still going strong after 13 months use which is a pleasant surprise -- must have been the cold that effected them.)

They should have lasted longer as they were still "OK" but not as good as new. And I wanted to try a new set of "silicone" batteries that had been sent by a battery supplier free of charge. More on those another day!

If you need many AMPS to drive your chair because you live in a hilly area with a fast tall geared "faster" powerchair or use long steep ramps and you are fat or play wheelchair football or something -- then get these. Great for performance due to very low internal resistance. Can be fast charged WELL too...  I charge my chair in around 1 hour. Don't expect quite as good a cycle life as you will get from the two Gelled Acid batteries on this page though. AGM technology is better suited to slightly lower overall total discharge levels and faster current release (and charge). I like them. Most people would be happier with an MK or other premium GEL battery though.

Power BatteryPower Batteries Group 24

These 75 amp hour deep cycle batteries were sent to me to test free of charge.

I used them for about 7 months. When fully charged they gave acceptable performance. After a little use (say half an hour walking the dog) they lost the power to wheelie or drive up the ramp to my van with me (a fat bloke!) in a 6 mph powerchair.

The 6mph is pretty relevant as the taller the gearing the more current or amps the powerchair demands to climb a ramp. In my case with that chair that would be 100 amps as the controller was using the max power it was capable of according to my clamp meter.

The voltage just dropped away though. So the actual power needed also dropped away.  For this reason I could only recommend these for low powered or smaller powerchairs and scooters. Range didn't seem too bad. But after 7 months was starting to suffer and the lack of power problem was getting worse so they were replaced. I have no idea how much they cost as they were supplied free. It could be that they were faulty maybe? Although I doubt it. I would happily test another set if they were supplied again.  I was rather hoping that they would perform better. But again I am not a normal user and even the very best batteries only survive 10 to 13 months with my usage style/pattern

Haze EV (Electric Vehicle) Batteries

EV battery Hazehttp://www.hazebattery.com/index.html

These batteries were surprisingly good. They lasted me as long as the premium GEL batteries did and had the power to make my modified powerchair go like it does with the AGM type batteries. Wheelies even when 50 percent discharged too. Range and cycle life were as good as the best. 

I would recommend  these unconditionally if it were not for the fact that when they did fail after 13 months it was very sudden. So sudden that one minute I was crossing the road with apparently good batteries in a good state of charge and then nothing! Zilch! Totally unable to move one inch or get me going at all or home. Battery voltage read as about 80 percent charged.

Something inside failed. Suddenly, like a connection between cells, or something just failed like a fuse going! Never had a battery do that before. Didn't know they could.  This may have been a one off situation but the idea of getting stuck and unable to get home -- even slowly -- really doesn't appeal. If this doesn't worry you then get these in place of the Sonnenschein A500 or MK GEL batteries and save some cash! f it does then spend the money. Was going to cut one open so I could see what failed but it was too cold out there...

Halfords Leisure Batteries

While in the car accessory shop Halfords, I spotted some batteries that were the correct physical size (Group 24) and 70 Amp Hour clearly labelled "DEEP CYCLE". For about the same price as a cheap starter battery. Mmm interesting but highly unlikely I thought...

So I asked the guy that was the resident battery "expert" if they would be suitable for proper deep cycle use in the powerchair I was sat in. He said yes absolutely, and that they have a full 2 year warranty to back it up and were perfect for a powerchair. This was going to be fun. TRUE Deep Cycle batteries don't have 2 year warranties even if you pay four times as much since even really good ones will not last 2 years if heavily cycled..

I explained that I expected them to last about 3 months maximum. He insisted they would be perfectly fine. So I bought a set for a laugh. They performed great, with normal range and good "wheelie power" performance on the first week. The second week they were getting a bit weaker and shorter in usable range.

After 5 or 6 weeks they couldn't get me out of the house and into my van without the battery warning flashing... Seriously.  This I expected.  But Even I expected a couple of months!  So they swapped them under warranty. 5 times!  That kept me going for about 6 months in total.  Then they refused to honour the warranty.

So I got all my money back. Not all batteries are equal. Be careful how much you "save".  This also put me right off ALL Halfords batteries completely.  But they keep on building NON ACCESSIBLE new buildings with no disabled access illegally with much of the "stock" and displays  upstairs where I cant get to it so bugger them!

See also:  Inverters and Chargers  &  All about Powerchair and vehicle batteries and  Which batteries to buy


Related Pages

Detailed PowerChair Only Menu

Lithium Ion Batteries for Powerchairs and Scooters

Inverters and chargers for powerchairs

Fast charge your powerchair or scooter

Fitting Anderson Connectors to your powerchair




Home     Site Map     Links    Contact Me     Privacy Policy 




Content, Images, Software & Design (c) Burgerman 1996 & aggressively protected by whatever means needed  --  Message Board

  eXTReMe Tracker