Li-Ion Power Tool cells work great for RC!

[starscream]

Sounds like these cells are screamin for MEC's solderless power tubes :027:

[nl12]

The next generation Li-ion cells coming out this year will be much better than these; they are coming out in the dewalt 36v setups, search dewalt 36v to read it, I also asked maxamps about them they said they would be carrying these cells as well. I may switch my truck over to these new Li-ion cells if they are as good as the hype suggests. They are supposed to deliver more watts per weight than anything else avalable, and charge fast.

[MetalMan]

The only thing I am worried about with the new A123 cells is energy density and cost. Energy density is capacity per weight. The A123 cells are very capable of high discharge rates, like 100C peaks, 50C bursts, and 30C continuous (I think). IMO, that is completely unnecessary unless you are doing a speed run where weight is a major issue. If they were to produce a cell with better energy density and a discharge rate of 15-20C continuous, then it would be a much better cell.

[Serum]

amen.

in other words;

it is not only about the maxximum energy per oz, but it's also about capacity per oz..

[Serum]

they claim to be the most energy delivering cell per kg.

http://www.a123systems.com/html/tech/power.html

3000 watts peak to be precise..

but, if you look to the flightpowers, their 6600 22.2V pack weights about a kg (1013gramms) and is able to deliver 3700 watts.. (fligtpower cells are 3.175 V @ 30C discharge.)

This is about power per weight, not about durability.

[maxxdude1234]

Metalman, I think you've got to realise that these A123 cells are not aimed at the rc market, they're aimed at big heavy powertools are other such applications. For powertools, 100C burst discharge is quite neccessary and 20C charge is also pretty handy! I don't think these cell's are designed to be the next ultra-lightweight, energy dense lithium cell -they're built to be heavy duty, and going by some of the info on that site I would say they do a pretty good job.

[nbcaznmaster]

The question is! are they cheap?

[nl12]

cheap? not at first like anything new, I think they will be great for rc applications as long as they have good capacity, if they are as good as I hope; they will be replacing my hyperion 3700 lipos

[nl12]

Originally Posted by maxxdude1234

Metalman, I think you've got to realise that these A123 cells are not aimed at the rc market, they're aimed at big heavy powertools are other such applications. For powertools, 100C burst discharge is quite neccessary and 20C charge is also pretty handy! I don't think these cell's are designed to be the next ultra-lightweight, energy dense lithium cell -they're built to be heavy duty, and going by some of the info on that site I would say they do a pretty good job.

They are also for hybred cars, they are designing a toyota prius battery that weighs 20 lbs compaired to the stock 100 lb NmHi battery, so they may come through in the energy density too. They are using nano technology to improve the cells, if someone starts using the same technology on lipo cells then we will definately have the best of both worlds

Metal man the physical size of each cell is 2 9/16" long (basically 2 1/2")

3/4" round.

As far as I can tell so far is they are 1500 mah 3.7 volts a piece

With minor mods they fit 2 long and 2 high in an E maxx.

I have mine built for the most part just need some large shrink to put them in. I will try and get some pictures soon.

For the record it is realtively easy to put a 4s 2p 14.8 3000 mah in 1 of the battery trays. So when you make 2 of these packs (1 for each of the battery trays) you can get 6000 mah at 14.8 volts.

If a person had extra room or wanted to do alot of extra work you get a 5s to work.

Sooner or later I may do a 5s but I would need to upgrade my charger and do some mods to the battery tray.

Right now I have a 6000 mah pack and have roughly 140$ dollars into it.
I like the packs alot better than lipos do to the fact they are in a metal case and can take alot of abuse vs lipos.

[BrianG]

I know someone said they weight less than NiMH, but more than Lipos of the same voltage/capacity, but how do they compare weight-wise once removed from the case?

[MetalMan]

Originally Posted by maxxdude1234

Metalman, I think you've got to realise that these A123 cells are not aimed at the rc market, they're aimed at big heavy powertools are other such applications. For powertools, 100C burst discharge is quite neccessary and 20C charge is also pretty handy! I don't think these cell's are designed to be the next ultra-lightweight, energy dense lithium cell -they're built to be heavy duty, and going by some of the info on that site I would say they do a pretty good job.

Right, which is why we would be worried about power/energy density. Heavy duty is what they need to be, they are going into power tools that have high stall currents and that might get banged around a lot. The A123 cells definitely appear to be good, but how good for RC we will found out.

fishmasterdan, thanks for sharing how these Emoli (sp?) cells fit into battery compartments!

BrianG, it might have been me that said these cells are lower weight than NiMh, but heavier than LiPos. This comparison is with the cells outside of the case. Even with the case, they should still be lighter than NiMh for the same voltage/capacity.

You cannot removed the metal case. They are very similar to NIMH cells. The main difference is 1 lion cell is 3.7v and 1 nimh is 1.2 v.


I just ran a 4s pack for 15 minutes and only drianed off 1 volt. Used in an E maxx 8xl setup. roughly 2000 mah was drained off (still chargeing). Motor was warm batteries did not seem to change temp. cold to the touch.
I can see 35 min run times REAL EASY.
Need 10 pick up a 12v alarm.

could you take a picture of your cells?

[coolhandcountry]

Fish master do you have a pic of them out of the case. I like to see what they look like.