Johnathan

iTrader: (1)

Roadrunn3r, people with damaged/bad lipo's soak them in saltwater. i have only heard of this.

muahdib4

Those are 7.4v though and it's already been discussed that 7.4v is to much for 1/12th scale. I think he's talking about something that produces 4.8v like current 4-cell....I've heard that something is in the works for that.

jiml

iTrader: (3)

Soaking a lipo pack in salt water will discharge it, making it safe to dispose of.

or8ital

iTrader: (38)

Late night? Any pictures?

danimal1965

Hey Mr Black. I first would like to thankyou for all this great info.My questions are if you say that NIMH are faster, why? and for how long in a 5 minute race? I'm assuming that you are comparing a freshly peaked nimh to the lipo.Thanks. Dan.

MrBlack

NiMh are only faster at the beginning of a run and only with certain Motor sizes due to the resistance both internal as well as external that NiMh cells have.

The curve of a NiMH is like an arch going down steeper and steeper from the first second. A LiPo has more of a straight slanted slope so within the first minute or two the NiMH begins to show less voltage then the LiPo.

For some people speed is measured before the first lap so for them it is safe to say a NiMH with 6 cells that tops out at close to 9.6V volts delivers more power and a LiPo that tops out at 8.4 delivers less. However it is not that black and white as LiPo have less internal/external resistance (this is why NiMH get so hot, that is power being wasted) and can deliver that power more freely.

Think of it like a garden hose hooked to a bucket. if both batteries are the same capacity then the LiPo has a bigger hose where the NiMh has a smaller hose giving it more pressure but this creates leaks as it flows which wastes water.

danimal1965

Thankyou Mr black. I've got a MRC 989 on its way. Can it balance a 2 cell lipo some-what without buying an extra balancer. I mean threw the Pos and neg power wires only, by reducing its charge rate as it's about to peak. Dan.

MrBlack

I am not sure we have not done any testing with the 989. I would contact MRC to see what they say.

syndr0me

iTrader: (32)

Na, still figuring out how to mount the electronics in the Type-R. I'll try to get something up in the next day or two of the charger/ps combo. I've been delayed a bit due to some pesky real life stuff.

big al

iTrader: (10)

Hey guy, this is a very informative thread and I was hoping I could get a question clarified. I've just recently purchased a Duratrax Ice and hope to pick up a lipo in the next couple of mnonths. I race Sliver can and stock and 19t occasionally. My question is: What capacity pack do I buy as I have read that you should never go below 80% discharged? My local track runs 6 min. stock and 7-8 min. silver can (TC), would the team orion 3200 meet these needs. Thanks--Al

muahdib4

Easily. In a 5 min main with a silvercan mini...I use 600mah roughly.

Iceracer

iTrader: (1)

A friend wants to go flying tomorrow. I pulled out a couple of 3 cell lipo packs that were fully charged when I put them away last October. One took around 5 minutes to repeak, and the other took around 8 minutes. This is at a 1C charge rate. Shows they really hold their charge. Just try that with a nimh. It will be interesting to see if they have degraded run time or not from sitting for 5 months.

syndr0me

iTrader: (32)

Here's a picture of my charging gear that I use to race with. I alternate between two of the Carbon LiPo packs, only one of which is shown. This is all you need to race and be competitive with LiPo. Therein lies one of the main reasons it's so attractive to many of us.

r0adrunn3r

iTrader: (3)

So to compare - How many NiMH packs would you need to stay competitive in say 27Turn stock class - If you ran 3 qualifiers and 3 A mains?

403forbidden

iTrader: (11)

Between 4 and 6...with another couple of lesser packs for practice runs.