UltegraSTI

iTrader: (20)

speed, voltage, weight etc are all great. but honestly. 2wks ago i did my 1st race mtg showin up without any nimh. only 1320mah 2cells for my exotek (1/18 touring), and just the sheer convienence of lipo was more than its worth. i didnt have to get the next pack out, discharge it, tray it, wait for right time in between rds and after marshallin to start the pack, i didnt have to yank the old 1 out, tape the new 1 in, over and over each rd. i could relax, do somethin else, rest, talk, look at other stuff, watch races. who needs all the work anymore. not I.

who knows how long it'll be before your old 4200s show age, dropped cells, lower intake of charge, flat in stock is not good. even with those weak mod BL motors.

you'll find a way to mount it all, just have a nite workin on the right for the right orientation.

i can only make 1 last, strong, pt. if folks are willing to develope a 1cell (3.7v) battery for 1/12 scale b/c those guys are even lookin beyond 4cell and no1 seems to have a quarrel bout usin a rx pack for the electrics (some have to remember how to wire them properly heh).......i think that explains itself.

similar situation in TA. brushed/4cell 17.5/4cell and 21.5/lipo (w/4.2:1 FDR limit). people are runnin out and gettin those 21.5s as fast as possible. 1 the lipo factor already mentioned, but its a tick quicker after the 4cells lose their 1st min 'bang' and in enduros especially when they can go 15-20min no sweat where as 4cell runners are strugglin to make 9min (17.5s stretch 10min).

choice is clear, nimh has had its day. have fun.

R

PS-I'd rather have 1 lipo smoke itself outta oxygen inside my ammo box while chargin then to be blinding and/or burning folks with acid-laiden projectiles. i think our scandinavian friends agree with a long time ban on EP racing b/c of nimh.

crazy4wdracer

iTrader: (25)

I personally use the Duartrax ICE Charger with a 15A power supply with an Orion Carbon 3800 LIPO that doesn't even need balanced. The Hyperion charger has a built in balancer so you don't need one separate from the charger. I had an LRP Pulsar which was a great easy to use charger, I would have gotten the LRP Pulsar 3 that can charge lipos but it came out after I got my ICE. The ICE is still a great charger though. I have been using lipo cells for about a year now and have never looked back to nimh packs.

KREATOR1

iTrader: (8)

thanks for the info

mac853

Thanks for reply!
About that problem of nimh or lipois been soved, i asked 1 of the sponsor/chairman of the races, he said me about those kind i have written in the top are just theories made for asking us, not proposed, the rules kept are these:
NIMH 7.2v
or
LIPO 7.4v
with 4000kv or 23T motor

Duratrax ICE, ok well, thanks!
But i have also anothers questions:

How many 3800 will you bring to race, i think 3800 is too low,that will spend so much time to recharge, the another trouble is our races are so little break time with lack of mains, each 45 min per main, how about 3 packs or 2 is enough?

About the built it balance chargers, when or how many times after using you may balance it?

Please don't hesitate to said anything, in fact i don't understand nothing(nearly zero) about LIPOs.

Grizzbob

iTrader: (2)

No worries, you can't learn unless you ask questions. As for how many packs for the conditions you mention, normally one LiPo is enough, but with tight time constraints, you might be best off with 2(you can just keep the charger runing near continuously, so you shouldn't have to worry about not having time to charge). As soon as one finishes charging, you can just start the next one right up, & stay ahead of the schedule(& remember, you don't have to have great timing with LiPos, they don't need to peak RIGHT before you use them, like we had to do with NiMh's & NiCd's, a LiPo will sit a LONG time & not need a repeak). Though that does bring up the one downside I've found to them, the charge time. Because of the charge method, it does take longer to charge a pack of similar capacity to a NiMh, because the charger will use a constant current till the pack reaches 8.4 volts, but after that it'll start turning down the current to maintain that voltage till the charge current finally goes down to 0, that can take quite awhile(so what would've taken maybe 20 minutes before can now take 40-50 minutes because of that finishing method for the charger). But for you, I think a second pack should still work out fine, just keep charging without a break & you should stay ahead of schedule.....