Do you have size constraints ?

What battery type? Different batteries will need different chargers.

Charging 2 batteries in series is not the best idea, one battery may charge faster than the other leaving the other battery under charged. The same issue happens in multi-cell LiPo based batteries hence the use of a balance charger and balance port.

You'll want 18A for the battery to charge in an hour which is quite a lot, my biggest charger is only 5A, the one I use most is less than 1A (I think it's 850mA - and it takes ages for my 5000mAh LiPo to charge!).

Also, be aware that charging too fast can cause the batteries to over heat. If they are SLA batteries they charge better if you charge them slower too. If LiPo they have less chance of going boom and increasing their life.

So not exactly advising any chargers but some food for thought.

If this is for powering the wheelchair motors we have been discussing, then you will want either sealed lead acid or gel cells (@jstarne1 has posted good links in earlier discussions, so you can either search for his posts or maybe he will chime in), and you can pick up a charger for electric wheelchair from eBay for not too much that would do a good job. I got one for $35 or $40, brand new, from an eBay seller. It came with a 3Pin Amphenol connector, and I picked up an Amphenol jack at Radio Shack, but you can always cut the connector off and make your own connections, or just solder on some big alligator clips to connect directly to the batteries.

Alan

Canadian Tire sells small motorcycle\snowmobile battery charges (for 12v SLA or gel batteries)....

Josh uses/recommends PowerSonic SLA batteries.

Rich, I never said I would be charging in series. I don't mind if they take a while to charge.

ww321q, No I don't.

rryerson, Thanks for the info.

thetechguru, yes I am, and i'm looking for a cheap battery/charger combo I can get 2 of to run the chair.

looking at these batteries, but have to get chargers for them. Yes? No?

www.ebay.ca/itm/UPG-2-Pack-12V-18AH-BATTERY-BOOSTER-PAC-ES2500-SLA-VRLA-RECH-/190931572276?pt=US_Rechargeable_Batteries&hash=item2c74689634

What charger should I get?

You charge in parallel and optimal charging rate is 2.5 amp per battery. So a charger that puts out 4-5 amps will charge two at once at a ideal rate. Each battery has a charge rating, min, max and optimal. The power sonics do great on a 2 - 2.5 amp current. You can charge them faster But it reduces the overall batteries life. Don't try charging a 9 ah battery more that 1C which is 9 amps. For a 7 ah battery @ 1C that's 7 amps and so on.

Whenever there is a single battery that has the same capacity you need as a couple if small ones you will notice you save money. This is name brand , with warranty free shipping power sonic 12v 35 ah battery with load handles

Ebay item #171043247259

69.99 free shipping

Schumacher 8 amp charge 2 amp trickle is a good choice here

Ebay item 231162794636

About 22 dollars.

Probably free shipping is to the US only. Us Canadians get hosed with shipping from the States

Just search for the same item on ebay.ca

I really need to try not to go over budget(I know, budgets in robotics never hold). The 18AH batteries in series will give me 24V 18AH. So if I get a battery charger capable of say 5AH and put the batteries in parallel I could charge both at 2.5A?

Why do you need 24 volts? What could you possibly utilize it for? Also it causes wiring to get complicated because 24 volt means you can't use a standard charger. Even if your using wheelchair motors you can run them at questions volts and still move around a 200 pound bot.

The wheelchair i'm looking at uses a 24V battery. it's pooched so i'm looking into another battery setup.

By "questions" do you mean 12V?

You can use 12v on wheelchair motors and it simplifies things for you.

any? and still get a lot of torque?

Yea , you gotta remember wheelchair motors are ridiculous and at 24 volts pull a 500 pound load 5 mph. Your robot is not going to weight that. Even if it's half that's 250 pounds at 5 mph. It's still lots of power just less that at 24 volts. Having less power in this case is safer too.

The one i'm looking at is an Invacare action power 9000 storm series.

Not sure what it's max load is but I guess I can take your word.

battery http://www.ebay.com/itm/like/321273208300?lpid=82%3C/a%3E

@Josh, Hey I just noticed your new user name. Great idea. It shows that you are partner of the company. It's hard to know that unless you keep telling people.

Except the user details page for that username is broken, i assume due to the forward slash.

I took the slash out , i guess it didn't like it but the link seems to work now. Yea i figured it would be best to add it to the name otherwise people would just think I'm some guy talking at random about the projects lol.

Perhaps you should see if EZ-Robots will add a new location just for you and ant as XL-Robots

Anyway, we have hijacked this topic... Back to amps and batteries and stuff

True , we were totally Thread pirates , anyways you should have info to get yourself a good sized battery cheaper than the originals you were looking at.