Greetings from Clalifornia

[gandalfretlaw]

Hey there. Walter Here. My wife is disabled and I keep her in wheelchairs from the used market. We definitely don't have your budget, but you did get me to check pdf sheets on our latest cheap pair of batteries. In my experiences the Cheap batteries last her about as long as the expensive MK ones.... a little under a year or so. I just bought a pair of Raidon 1U batteries ($125US shipped). It could be that part of our problem is the 1U batteries themselves as they don't have the capacity of the larger ones and she runs them harder (deeper discharge) than the others would be. I'm thinking about installing anderson plugs but these batteries are only rated for 10.5A charge. You've got me thinking about different charging methods though. I do have three of the iMax B6chargers (RC combat warships). I'll have to look up the specs and see if they will do voltage limited charging, don't remember. Pretty sure they don't do float though. Watching a couple of the Hyperion chargers on ebay, but it looks like they go for $125 used. I wonder if there are some Chinese knock offs that have the Pb feature set.

I can't seem to understand the various battery and charging graphs. Haven't got the sight as of yet I assume. I work in IT and assume they are not hard to figure out. Perhaps I should watch some youtube videos. I did see that they have LifePo batteries for 1U but they are $850 and only increase the amps from 33 to 40. Kinda wonder about building some out of cells. Rebuilding some LIpo packs for my little drill right now. Need to get some better soldering irons. Currently we are doing the Pride Jazzy Select series and I have around nine parts/backups for her. Also have a Jazzy 600XL that I might consider playing with. I need to take the controller apart and clean the contact as it's a pain to turn on. It uses the larger batteries like you like. In my experience they run twice the cost though for new batteries. I generally buy stuff of ebay.

I do have a question that I have not found an answer to. I think it is possible to do a parallel tap on wheelchair batteries. The wheelchair itself uses a serial hookup to produce 24V, but I theorize that you could run wires and tap for 12V (at double the amp hours) for powering things like cell charger or gps. I'd rather like to hook up a 12V car cigarette lighter port for her. But I can't find anything on doing both setups at once. Perhaps I'm missing something. Perhaps I should just pull out some warship batteries and try a proof of concept. My big fighting warship is a H-39 German Battleship (laid down after Bismarck/Tipiz but never completed). My whole reason for the parallel tap is to keep the draw balanced across the batteries. I'm decen't with electronics, but far from a electric theory engineer.

Eventually I'd like to see her with better range. We have an unmodified Dodge Grand Caravan and I use a 3/4" 2'x4' plywood sheet as a loading ramp. The chairs don't do that by themselves but effort is minimal for me with the wheel assist. It's fast and easy. Got the idea from a guy who had a broken electric ramp and just pulled it down manually all the time. She doesn't drive, but loves to cruise around town and go on adventures in San Francisco and Berkeley. We live in a small town 70 miles from SF.

https://www.raiongroup.com/content/RG12350FP.pdf

[Burgerman]

I dont know where to start. But everything here is already covered. Ask one question at a time on the forum to get links and advice.

Those batteries are junk by the way. And too small. And you wont find a decent charger in the hobby world for them unless the Celpro PL8 with the correct settings and termination current.

[LROBBINS]

Take a look on the WheelchairDriver.com pages (the parent to the forum) to see how Burgerman wires up Anderson connectors to be able to safely switch between 12V parallel and 24V serial wiring. There is no way to do both simultaneously without creating a short circuit, so if you want to have 12V as well as 24V at the same time you need to use a DC-DC converter. The Chinese sell some pretty potent ones for reasonable prices (e.g. on ebay). If you do go that route, be sure to fuse both inputs and outputs of the converter - to protect the chair from converter faults and the converter from faults in whatever you connect to the 12V. Also, do be aware that on a wheelchair the chassis is NEVER connected to the battery - a wheelchair user can't run away if there's a short to the chassis!

[gandalfretlaw]

Cool. Thanks guys.
I'm thinking of getting a Promariner ProSport 20. Specs look much better than Soniel chargers which generally don't have as many amps. Mount it to the bottom of the seat and probably go through anderson connectors although I could proof it hard mounted. Should be able to get one from ebay for $130 or so. The Anderson connectors would be more flexible configuration wise though. Also like that I could easily pull up multi-meter readings easily.

I thought there must be some reason why both parallel and serial wouldn't work together. Probably would have saw it instantly if I drew it out.

Like I said I've bought brand new MK batteries for double the price of black box batteries only to get about the same life. No doubt it's that she drains them down too much. A fast charge should help with that. Perhaps I can experiment with the 600XL. Heavier duty machine than the selects. I've probably dealt with 50 wheelchairs in the last 20 years.

[Burgerman]

You CAN charge (decent) lead batteries at up to 100, 150A without problems. At least initially when they accept such a charge. And as a parallel or series setup. I do it daily. Very old page. But its not quite as simple as you think. http://www.wheelchairdriver.com/faster- ... arging.htm

As for chargers hold off for a bit. You dont know what you want yet. Likewise dont but an all in one lithium 12V replacement. Those are a waste of money. Read the pinned lithium thread at the top of the main forum. Post 1 at least!

[swalker]

Welcome aboard!

It is pretty easy to show that MK batteries are superior to the cheap ones you have settled on. If your MKs behave the same as the cheap batteries, I suggest that either you got a bad MK battery (possible, but unlikely), or that they are being charged in a way that damages them.

What kind of charger did you use to charge the MK batteries?

I have used group 24 MK batteries with great success in 3 wheelchairs. They are the only lead acid batteries I will consider for my wheelchairs.

Steve

[LROBBINS]

Do be aware that MK makes two different types of batteries - gel, that are the ones said to be good, and AGM that are no better than any other basic AGM, in other words, lousy for wheelchair use.