Opinion My 2015 Permobil F3 10amp Hr Battery Charger Died

[F3Head]

Permobil battery charger

Permobil

Adequate Charger for MK Group 24 74 amp hr?

My 2015 Permobil F3 10 amp hr battery charger crapped out. My batteries are three years old and had seen better days. I had this old Super Mobiline battery charger laying around in the closet. Is this charger adequate for charging the MKs?

Any advice ?

Thanks,F3HEAD

[martin007]

That charger works for you, but it is not the most recommended.

[Burgerman]

Lets put it like this, any charger will "work"...
Most mobility chargers "work" .

But to charge a battery propery and get good range, and the best service life takes a lot more detailed and correct knowledge and settings.

I cannot know if either of those chargers are any good for gel batteries (which is different to AGM batteries) without knowing exactly what they do.

No charger that claims to charge gel and AGM at the same time can do that correctly unless it has some means of setting a seperate gel, AGM, and wet lead acid setting. And even then most do this incorrectly.

So what do each of those chargers really do?
For MK Gel, or any gel battery, you need ideally 23A (but this has a limit of 12A due to the stupid XLR connection) and at 28.20V max at room temperture. It should hold the battery there at this voltage until 8 hours has passed, or until its charge current drops to a low 0.1 level, whichever happens first. And then it should fall to a lower 27.0V indefinitely. After around 14 to 18 hours its fully chargeged/saturated.

If it does not do EXACTLY that, its not ideal and will never give the best service life. Only real way to know is to use a charger that YOU can configure, or buy a dozen chargers and start monitoring them all as they charge. The charger manufacturers seldom give or even know this stuff.

[martin007]

I want to add something.
You can keep batteries floating indefinitely.

This is the proper charge profile for GEL batteries.

https://www.wheelchairdriver.com/MK1.pdf

[Burgerman]

If you intend setting a float voltage it should be a little lower for long term float.
13.7or 13.8 for overnight to add a top up at the end faster. 13.5 for anything over a day. 13.3 for long term storage when not in use.

Double that for 2 in series obviously. And in summer, over 25c reduce this by the amount shown in the MK charge sheet. That applies to float and CHARGE Voltage.

[swalker]

That charger will put energy into your MK gel batteries. It will do it at a maximum rate of 5 amps.

That charger has a switch, with one setting for either gel or SLA (sealed lead acid). The other setting is for flooded lead acid.

From that, I can infer the charger will behave the same for both gel and SLA. This is unlikely to be optimal for either gel or SLA batteries.

So, it is likely that charger will shorten the cycle life of your MK gel batteries as well as reduce the wheelchair's range. If these limitations are acceptable to you, it should be OK to use the charger.

Note, those conditions would not be acceptable to me. If I was my money to spend, I would use that charger only for a couple of charges while I procured a proper charger.

Steve

[swalker]

Also note, your Permobil charger that died is an 8 amp charger, rather than the 10 amps you indicated in your original post.

I have had good luck with the 8 amp permobil charger (the one that died) and use them regularly.

Permobil currently makes a 10 amp charger which they state is intended to be used with their new style batteries. I have no experience with those.

Steve

[Burgerman]

Their new batteres are a gel/AGM battery. The AGM part plays no part in the chemical/electrical part of the equasion its just an inert seperator. They are actually the very same battery as far as I can tell, as the ones sunrise supply. They are 80Ah, gel chemistry, pretty good quality. They are a rebranded version of the Sunrise supplied, permobil supplied, battery. Same exact electrical specs, same sizes, shape, lifting "rope", same terminals and just different labels.
You can buy these from permobil, or sunrise, or you can just order the HAZE 80Ah GEL on ebay as the 3 are all the same internally. But they are £220 each at the moment.

As for the special permobil charger, whell it too is a gel/AGM generic one rebranded standard 3 stage charger. But it is adjustable internally for AGM or GEL. Wether this is actually the CORRECT settings is unknown. But thats all I can tell you about permobils "own" special battery and charger... They make neither. But have tied these "special matched components" together in their customers mind. All clever marketing. You can buy the HAZE 80Ah GEL battery cheaper I would expect on eBay. And chargie it or a "permobil or sunrise version, as the GEL battery that is is.

I orderd the HAZE ones for my backup chair. Works pretty well. Has more capacity than the MK, and similar impedance, and around 20% less cycle life. In theory. But its bigger, so lowwr average DOD means it actually should last just as long or better.