Batteries for wheelchair

I was told I had overcharged my batteries my 7 month old batteries and must pay for new ones. I did not accept that I had never been given any written or verbal instructions on how to charge the battery. I won that argument…
However I still have no authoritative or written advice on how to get the best out of my battery.
Am I unreasonable to expect the supplier to give users advice on how to manage their product?


Hi @chatkun, welcome to the community.

Usually battery management to prevent overcharging is through original equipment manufacturer’s (OEM) battery chargers. These usually manage the charging process so that batteries aren’t charged more than what the batteries are designed. If the chargers were overcharging the battery then it would be warranty claim or fall under the Consumer Guarantees.

However, this is only one aspect of battery management. Leaving batteries permanently on chargers between uses can cause battery damage, and in worst case, a battery fire. This is especially the case for lithium ion batteries used in modern motorised wheelchairs and mobility scooters. There has been a lot of media attention to this of recent times as it has resulted in house fires, with wide spread warnings not to leave batteries on chargers when fully charged. Government Agencies, such as the ACCC Product Safety have been issuing public bulletins also advising of safe recharging practices.

Such practices are becoming common knowledge and thus it could be argued that if the battery failed because of the battery being left on the charger, then a reasonable person possibly knows that this should not be done for a number of reasons. Therefore any damage could be seen as the result of misuse.

A way to look at it is a reasonable person knows not to rev an engine excessively for a long time as it could cause engine damage. Car manuals possibly won’t say to not do it (if they did think of every possible abuse of a vehicle imposed by a consumer the manual would become an encyclopedia). If a consumer overrevved an engine a manufacture won’t repair the vehicle under warranty as it is common knowledge that such is misuse of the engine.


Most but not all state to never leave batteries on charge, and to try avoiding discharge below 20% and charge above 80% to maximise life.

With many suppliers now delivering so-called smart chargers one might think all are smart enough to not overcharge, but that is not the case. Even phone and computer batteries are easily ‘mismanaged’ even doing one’s best to follow the advice the manufacturer provides.

The 20-80 range seems the sweet spot. Should that information be supplied? Yes unless your wheelchair uses lead acid batteries as is probable - and then the charger company should include guidance on its limitations and best use.

Part of the issue is vehicles use lead acid batteries. Their care is usually included in the owners manual but as for charging off-vehicle? Nada.


It’s not unreasonable. The wheel chair should have come with an owners manual/s. This should have included clear and concise instructions on safe use, battery life, when and how to charge using the charger supplied.

What is in writing provided by the wheel chair manufacturer/importer offers the most reliable source of information. If the retailer is saying otherwise, to do something different upon which the purchase decision was made, it too should be in writing. It should have been provided by the retailer before the decision to purchase with a full explanation that the average customer would understand.

Note the technology to ensure a battery charger or controller does not over charge a lead acid battery is cheap and well proven. One feature to check with the supplier or manual. As @phb mentioned it’s best to not leave your battery on charge once charging is complete.

You did not mention what type of battery was supplied with the chair. Following on from the comments of the previous posts the most common type supplied is a deep cycle sealed lead acid (SLA) battery. They come in two slightly different types AGM and Gel. They are similar but the recommended methods of charging are different. Both do not like being regularly discharged to near empty/flat. It significantly shortens the life of the battery measured by the number of recharge cycles. Having 50% or more charge left at the end of the day before recharging is a useful guide to longer battery life.

SLA battery life and capacity is also affected by temperature. The hotter the environment, (batteries also create heat in use and during charging) the shorter the life. The quality of batteries also varies by brand, sometimes reflected by the price, but not always. Some expensive batteries are just over priced average quality.

Other observations:
Electric Wheel Chairs come in many different configurations to suit different needs. The supplied batteries vary in capacity. Hopefully the retailer reliably assessed your needs. Your battery should have sufficient capacity to last a full day. If used daily the chair should be recharged every night.

Does your chair have a battery charge indicator? If it is regularly less than 50% it will shorten your battery life. Assumes it is an SLA battery. If you are often dropping below 50% at the end of the day consider a battery with a greater capacity (measured in amp hours) for the next replacement. It’s important to ensure that the battery is routinely fully recharged. The charger or wheel chair should have a way to indicate a charge is complete. Simple chargers have a LED light that changes colour. Smart charges will have a display that indicates full and switch to off or a standby/float/maintenance cycle to avoid over charging.

A more expensive battery option is a lithium rechargeable battery. The same technology (there are several different chemistry variations) as used in Electric Vehices. Typically 3-4 times more expensive than a quality SLA. Compared to SLA batteries one advantage is they can be more deeply discharged without loosing cycle life. They are also able to deliver greater power in bursts, accept top up (partial recharges) and faster charging with minimal loss of battery life. They require a matched lithium battery charger and controller. The sweet spot for total cycle life is as @PhilT suggested recharging to 80% and limiting discharge to 20% capacity remaining. Although lithium batteries will show minimal life impacts if fully recharging for a busier day or day out and running closer to no charge left at the end when needed.

Many have a tight budget when purchasing an electric wheel chairs or mobility scooters which have similar battery needs. Consider Lithium batteries depending on the type of lithium cells used can be a fire risk if damaged, poor quality or incorrectly recharged. Depending on one’s mobility without a chair a risk to carefully consider. They may also not meet air transport regulations if one is travelling with a chair.


Thank you for all people who responded. One thing I didn’t mention, my previous battery lasted 5 years. I don’t know if it was the same type as the one have now. I had no reason to think I was doing the wrong thing.
My conclusion is that batteries are complicated and various But I think that the industry could do more to help consumers understand the battery that they have.
Thank you Melissa for suggesting a timer. I will explore this with maintenance officer at my Nursing Home.


Five years is a great outcome and life. Clearly something is different with the replacement battery which did not last 12 months.

What the industry should have done is offered a like for like replacement of equivalent or better quality. There is an assumption the charger you rely on has not developed a fault. The average consumer should be able to rely on the competence and expertise of the supplier. Not assured, but what is expected under the ACL.

1 Like

One of our quartz watches has a history of batteries going for 3-4 years over a decade+. I change them myself since it is not difficult and I have ‘the tools’.

The last battery from a well known bricks and mortar chain had a shelf date of 4/2024 but I needed the watch running so took it; installed on 23/2/23. It died a few days ago at 6 mos service life and 7 mos before its expected shelf life. The point is it happens.

I had paid for the $2.50 battery with cash and did not keep the receipt never having had a problem with button batteries reasonable longevity before. Explaining its short life and my lack of documentation at the counter I was simply fobbed off having no receipt and ‘we do not warrant batteries anyway’. I expected at least a ‘sorry you experienced that’ or ‘here you go with a replacement mate’ as a customer relationship exercise. Getting neither I paid the $2.50 and they lost a customer. It was busy and I had no interest in pushing and the shop was well within its rights.

On that basis you did well.

1 Like