Please help me pick out some lipo stuff

[EZap]

About to purchase lipo stuff. I would ideally like to swap the batteries between my crawler, my wraith and my old tamiya prerunner.

Cheap chargers as decent as not so cheap?

How many cells should I settle for?

Thanks.

[Charlie-III]

There are quite a few threads here about various chargers. If you ask 20 people, you'll get 20 answers.

Cell count, a lot depends on what your ESC's can handle. Some are a max of 2S.
For most 2.2 rigs, most probably run 3S LiPO. The capacity sorta determines runtime & may influance power.
Comping has it's own ideas as well.

I run high "C" 325mah 2S in my 1.9 comp rig, I run high "C" 850mah or 1300mah 3S in my 2.2 comp rigs.
The smaller mah makes it easier to fit in the rig and keeps weight low.

I can't answer your question (nobody can, we can only make suggestions), just give an idea on how to start.

[braq]

Hi,

give us more information from where you start. Do your rigs have batteries and ESC? If the Prerunner has been run with a 6 or 7 cell NiCd or NiMh battery, most likely that is the maximum it's ESC will accept, so you can only use a 2s LiPo with that ESC. Check what volume (the battery) it can accomodate, I think it is a TA02 chassis and has a battery tray that you still might want to use.

I like using 3s (less current at the same output), if your budget allows, maybe get an ESC if the above applies.

As for chargers, I am using a thunder 6a and it works fine for me. The only limitation I have found is the maximum current. Iif I use it for car batteries it maxes out at 3.9Amps @ 12V but for all my RC batteries it delivers great results.

cheers

braq

[EZap]

Appreciated.

The wraith is the main concern, it eats the 5000mah battery I bought for it in about 5 minutes. The rock crawler will run for 20+ minutes on the 3500. The old prerunner is just for shnits and giggles, stays on the shelf for the most part.

The wraith is all but stock, I'll upgrade stuff as it breaks. Although it's a crappy crawler with the 20 turn motor, I kinda like doing the little jumps with it and stuff.

I tried just going to eBay and was met with a million choices for batteries and chargers. Lipo is all new to me. I'll take any advice I can get.

[Charlie-III]

Originally Posted by EZap

Appreciated.

The wraith is the main concern, it eats the 5000mah battery I bought for it in about 5 minutes. Lipo is all new to me. I'll take any advice I can get.

OK, quick question, when you "kill the battery" in the Wraith, how many mah do you put back in?
The reason I ask is that instead of running it all the way down, maybe you're hitting LVC early and you only put 2000mah back in, thus it's not fully drained (meaning, drained to LVC/performance drop-off).
It's very easy to hit a false LVC with a pack that does not have enough "OOMPH" to meet a high load.

[braq]

Wow, 5 Amperehours in just 5 minutes, that would be a constant draw of 60 Amps.
Are you welding instead of driving?
I have a hard time believing this is really what happens.

Why don't you list in detail what you have,
is it LiPo, NiMh or NiCd, age of the battery, what ESCs?

Charlie has it, the consumption might not be what is written on the pack

cheers,

braq

[EZap]

Nice to hear that something sounds fishy.

The battery is one I picked up from the local hobby shop. Onyx 5000 7.2 nimh. Charger is a Prophet Plus AC/DC 4-7 cell nicd and nimh fast charger. It's alway worked fine with my other batteries.
I apologize, but the ESC in the wraith is difficult to get to, can't see what it says. Stock Axial stuff. . .

Wonder if I just got a bunk battery?

[PFC FNG]

I run the same battery on a nightcrawler. It lasts over an hour of hard crawling easy. I am not sure off hand, but if your esc has a lipo setting, make sure it is off when running with the NiMh batteries.