Reccomended Battery Charger

Unfortunately, at our regional our only charger was surged and a capicitator exploded. So, we have been borrowing our mentor’s charger. I found this one at Walmart, but I am wary of the output amps.
Any better ideas?

What’s your budget?

No matter what it is, I’ll always recommend this one. Have a small fundraiser or ask for sponsorship from a local batteries plus. We got ours on a steep discount and have loved it for two or three years. We have batteries that are from 2013 that outperform a few of our brand new batteries when tested. The hardest part is coming up with a labeling system for the batteries and a cart to carry them. We keep ten competition batteries and carry a fee for practice that we use cheap chargers for.

Best part about that batterytender is that it is 10 separate 2 amp chargers. Just add some sb50’s build a cart and go.


8 amps is over the recommended charge rate. If noticed you might be asked to remove them from the pits. This Schumacher charger might be a better bet. It is 6 amps and has a AGM mode. I don’t have any direct experience with it, but moss of our chargers are Schumachers

How did you put on the terminals? Most of the SB50 terminals I can find are for low gauge wire. Soldering is always an option, but if there’s a better way to do it, I’d love to hear it.

Why wouldn’t you solder them?

I don’t have anything against soldering them, I’ve even done it before. I just don’t know if it’s the “proper” way to do it.

8 amps is over the legal charge rate, actually:

R39. Any battery charger used to charge a ROBOT battery may not be used such that it exceeds 6-Amp charge current.
Not that we check that often, but I have tagged teams for chargers without Andersons if I notice them in the pit.

The “proper” way is to use reducing bushings in the SB-50 contacts. You are only carrying 6 amps. Less than “proper” can be acceptable. Just make sure everything is well insulated. Shorts when plugged into the battery have very high short circuit potential.

We have one of these chargers. It seem a little more sophicated than the Shumacher chargers. We haven’t had long enough to have a full opinion.

R39 says you cannot charge at over 6 amps. I know the general interpretation of that is you cannot a charger with an over 6 amp mode in the pits regardless of which mode you are using. Not being a LRI or the GDC, I am hesitant to make blanket statements on rule interpretation. For completeness: LRI’s are the final interpreters at the event, but they don’t have the authority to change the rules either.

I would rather go with something like this one but it appears to be out of stock at our local store.

The charger Frank recommended appears to not have an automatic stop? hard to tell from the pics.

but we bought the $200 AndyMark three bank charger last year, and have been mostly happy with it. The fuses near the battey connectors seem to be a bit fragile, is our only complaint.

We used individual chargers for years, with big Anderson connectors soldered on the leads. The usual failure mode was that the wire would break, next to the solder joint. Maybe it would work better if you spliced a medium size wire (10 ga?) to the original wires, then solder the Anderson connector to this larger wire.

The Shumacher manual says it switches to maintenance mode when the battery is charged. I am thinking that is an automatic stop. It not that clear from the web site.

If that is indeed the case, then it should be fine.

I should clarify that I’m pretty sure the particular charger in the first post doesn’t have any lower current charging options. It looks like you either get 8 amps or maintain. If someone shows me that they can and do use their chargers at 6 amps or less, that’s perfectly fine.

My team currently uses 2 of these:

They also make these in a single bank:

What ever charger you get make sure it has a setting or is designed for sealed lead acid batteries. They have a different charging voltage then regular lead acid batteries. This will effect your batteries performance in competitions. AndyMark has a nice 3 bank charger. I will be getting one for my Ham radio station. Most manufactures recommend charging at a rate no more then 1/3 the amp hour rating. This extends the battery life.

I had good luck with this one from Amazon

This one is a little nicer but more money

We also use these. Good quality chargers and bright, easy to read and understand red and green LEDs to indicate charge state. These are a buy once item, get something good and you won’t have any problems.

We use a bank of marine battery chargers like ChargePro 6A 1 Bank 12V Waterproof Battery Charger

These are intelligent and completely sealed so metal chips are never a problem and there are no buttons to set wrong.

We also use this charger. Worth every penny IMO.

I believe we soldered them. I though about using a few of the 30 amp power pole crimps as a starter and then crimping those inside, but that might also be a reason why I am not allowed to do electrical work for our team.

The battery tender chargers only push 2 amps, so the connection doesn’t need to be very impressive. The wires that come out of the charger are 14 ga, if I remember right.

They are also available with less than ten banks as well, and most are constructed with individual 2 amp charger maintainers for each bank.