93dabeast

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im new to electric and would like to know what a lipo does, what a balancer does and everything else in between. i have a rustler xl-5 and a vendetta tc and would like to go bl but im not gonna go near it until i have a full understanding of lipo batteries, the way the charge and balancing of the cells. can someone please help me understand?

Jeremy Z

LiPo is a battery chemistry. You don't need LiPo batteries to go brushless, but that is how to get the most out of it.

LiPos weigh half as much as NiMH for the amount of energy they have.

LiPos don't automatically balance out between the cells when charging like NiMH batteries do, so they need to be balanced with a balancer. The balancer discharges the cell(s) that are at a higher voltage compared to the others to keep them even. If they're not kept even, then when the pack is at a certain voltage, one cell might be low and the other one over-charged. When that happens to a great enough extent > fire. And it is a violent fire too; a chemical fire that can't be put out until the reaction is done. To be on the safe side, the smarter ones of us charge LiPos in some kind of fireproof environment. (as opposed to sitting there watching them charge, as the manufacturers recommend)

LiPos are more fragile than NiMH, both in charging, discharging, and physically. If you have a non hard-case LiPo, and it takes a hit, there's a good chance it is ruined. With regards to charging, they must be charged with a LiPo charger, or they will burst into flames. For discharging, they can only be discharged down to a certain level, so you need a LVC. (low voltage cutoff)

Basically, we accept these inconveniences because of the 100% higher power density and resulting extra performance.

Oh, one other thing is that LiPos have a VERY slow self discharge rate. They can sit on the shelf for months and still hold most of the original charge. This is a super nice benefit too.

My advice is to go with the brushless motor and controller first and stick with NiMH batteries. Ease into it. Enjoy that extra efficiency for a while, and a bit of extra performance too. Then, decide if it is worth it to you to go LiPo.

cool-joe

There are a LOTof preexisting topics already on these very subjects that cover all the parameters and opinions on the subject you're asking.
I'd suggest you do some reading.

93dabeast

My Feedback: (1)

the reason i asked the question in here is so that all the info is in one place as opposed to having to find bits and pieces of info. Jeremy did a good job of answering my questions and now i have a way better understanding of LiPo batteries.

Bigbangtheory

x2, as I just asked the same question in my thread. I think I will also stick to Nimh batteries for now.

I really don't have a friendly fire enviorment to charge Lipos right now, lol! Hate to burn down the entire apartment complex........

redfisher1974

I will tell you this, once you go lipo you wont go back.

Bigbangtheory

Maybe, but I just rather have my living space for now, lol!

cool-joe

By starting yet another thread on the same topic all you did was add to the bits and pieces of info.

93dabeast

My Feedback: (1)

thanks for the supportive info

Jeremy Z

I went back. I had LiPos for my planes and helis. Weight is such a big factor in performance with them.

When I got back into cars and trucks, weight is a lot less of a factor, especially since I don't compete. It was refreshing not to mess around with balancing, have low voltage cutoffs stop me mid-run, or any of that jazz. Just plug it in, start the charge cycle, and walk away. Charging two in series is no problem.

Another factor was price and availability. Medium capacity NiMh packs are pretty cheap now, and easy to find.

Not saying I won't eventually go LiPo again, but maybe not exclusively.

blank916

reguardless of it being the first or thousand-eth time. That was a great explanation.