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LiPo (Lithium Polymer) batteries in a Robot

LiPo batteries in a robot. Anyone ever tried?

I just thought if they work for fast RC Cars they mighit just work for my slow moving robots. Of course they are more expensive and you need a proper charger but when I think of all the batteries I have bought over the years I could have paied for quite a few.



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I use them all the time.

I use them too. They're great. Weight/power ratio surpasses NiMh easily.

The little, 7.4v 2-cell packs (found everywhere for $5-$10) are perfect. They are just about the size and thickness of a 2 AA pack, and they have just the right amount of voltage "overhead" when feeding a 5v regulator. I usually buy these guys 5 at a time from Ebay and I can count of 2 of the 5 crapping-out on me quite quickly. That said, when you figure the cost of these vs. regular rechargable AA's or AAA's --they are well worth the price even if you have to weed-out a few non-working packs.

Thanks for your comments. Do you have any problems charging them?

Anyone else?

Nope, use a balancing charger and you are good to go. I personally charge mine outside, because I have seen too many youtube videos of burning lipo's, but this is just to be on the safe side. Treat them nice, don't short them, don't try to suck too much current and use a proper charger and you will not have a problem.

--Oh, one more... Get them out of the house when they go "puffy". That's about it.

Smash the "puffies" with a rock, they seem to ask for it.

Sorry, I could not resist.

It's not exactly a robot but it will give you an idea why they are most suitable for a robot: http://letsmakerobots.com/node/30718

They are smaller, lighter and more powerful than regular batteries or rechargables. Yeah, if it's not for the mainstream where AA or AAA are still the most easy to handle power solution (no fancy charger needed) I would power up all my robots with LiPo's

I used them from the first robot and i'm very happy with them. They have certain advantages over usual batteries and NiMh, BUT you have to take care of few things:

- always use a dedicated charger with balancer for charging.

- don't over discharge them, use a protection circuit to cut off the load or at least to warn you when the voltage is low.

- don't short them, they might catch fire.

If they leak or go puffy dispose them to specialized batteries collecting places. In case you don't have access to one of this places, put the pack in a saline solution (salt + water), puncture it and keep it submerged for at least one day.  Lithium is very toxic and in case it catch fire you can't extinguish it with water. Usualy a new LiPo pack should come with usage instructions.

A safer alternative to LiPo is LiFe. They are a little heavier and with a lower voltage but are advertised to be safer.

If you need to power only electonics or low power motors, you may also consider using LiIon batteries.

The BatteryUniversity website seems to be a good source of info on all types of batteries.