Li-Ion Power Tool cells work great for RC! - Page 10 - RC-Monster Forums

cart213 · 06.02.2006, 02:26 PM

I tried out the emolis yesterday with mixed results. The power delivery was very strong, and I didn't have any issues with the cells being unable to deliver peak currents. The cells barely even got warm. However, I did a gps test and got a speed of 52 mph. My 12 IB3800 cells had been able to deliver a speed of 54 mph, so I was a bit disappointed.

But, today I charged up the packs again and realized that the charger was set for a max. mah of only 1200! That's why the cells were at only 4.05V after I charged them yesterday. I set up the charger properly this time, and now the cells are at a full 4.2V each. Hopefully, I will be able to get a higher top speed now. I'll find out this weekend.

MetalMan · 06.02.2006, 09:37 PM

Even if the speed still doesn't match up/exceed that of 12 NiMh cells, think of it this way: speed requires power. Your Emoli pack can deliver a maximum of about 720W (peak), and your IB3800 cells should be able to do 1200W peak. I'm somewhat amazed that the difference was that small, 500W is a lot!

cart213 · 01:24 AM

The emoli cells also weigh about a pound less, which should make a big difference. Btw, I didn't know that NiMH cells were capable of providing that high of an amp spike (14.4V X 83A = 1200W)?

coolhandcountry · 06.03.2006, 07:45 AM

to my understanding. The nimh cells if good ones can go a 100 amp spike but the voltage falls back. They supposed to produce about 100 watts of power per cell.

MetalMan · 06.03.2006, 10:08 AM

Right, I was going by what coolhand says. But, I remember those numbers back from when GP3300s were king, and IB3800s are even better, so they might be able to deliver more.

Serum · 06.03.2006, 10:12 AM

I don't know if these IB's are better metalman. i am hearing different stories.

Test results will show .. (i will do some testing with the eagletree) i've got a set of BK's IB3800's, the best they had.

Nick · 06.03.2006, 06:55 PM

I don't know if to go for the IBs or Limn, the only thing that puts me off with Limn is the cost and charge times, I'm sure when I get stuck in it will be worth it. Not sure though, it is all very new stuff still.

MetalMan · 06.04.2006, 12:25 AM

Quote:

Originally Posted by Serum

I don't know if these IB's are better metalman. i am hearing different stories.

Test results will show .. (i will do some testing with the eagletree) i've got a set of BK's IB3800's, the best they had.

I know some of the airplane guys (sailplanes I think) use NiMh for short bursts in which they pull something like 200+ amps. I can't recall if they did this with GP3300s, but they do it with IB3800s for sure.

BrianG · 06.04.2006, 01:02 AM

I'm all up in the air about this stuff.

One minute I want to wait for the A123Systems M1 cells from the DeWalt 36v line, but then I find they are only 2.2Ah, are kinda big (26mmD x 65mmL @ 70g), and aren't exactly like typical Li cells; they only charge to 3.6v (not 4.2v like others), which will make charging a little challenging. By the time I set up a 4s2p or 5s2p pack, I'll be at the same weight and size as equivalent NiMHs (or close to it).

Next, I think I'll try those Emoli cells from the v28 packs, but then I don't want to go with a 2p arrangement for weight and space (each cell is 26.5mmD x 70mmL @ 99g) since they don't have the burst capability.

That leaves LiMn, NiMH, or Lipos. LiMn are a bit pricey for what I need, but seem like the best choice so far despite some peoples mixed feelings. NiMH are just too heavy and bulky for what I want to use. Lipos, well, I won't go into that again.

:032: :032:

Serum · 06.04.2006, 03:08 AM

Did you guys see the new numbers on the flightpower cells? they are awesome.

Nick · 04:53 AM

These look cool, the charts are brilliant:
http://www.flightpower.co.uk/core/da...a_5s1p3700.htm

Would it be best to go for a 3s and 2s, or just a 5s? I guess to balance the weight I should go for two packs.

I love the charge rates with these packs too! Tested at 2.5c.

Serum · 06.04.2006, 04:53 AM

Those are not even the charts of the new types they have got.

their new cells should do a 50C peak discharge. maxxamps.. Go pack your bags..

Nick · 06.04.2006, 04:56 AM

50C? I don't know much but who will need 50C Lipos. :D

Can't see them on the site, must not of updated them yet.

Serum · 06.04.2006, 04:58 AM

http://www.flightpower.co.uk/acatalo...0-3700mAh.html

they are called new formulation.

Nick · 06:55 AM

Woah! So they are doing 50C packs at same price as 20C? Will that mean the packs are more efficent? Can't wait to see the charts.

I've just seen some of these do around 110amp bursts, will the BK9920 be fine with this?