Flat A123 Cells- When?

[stum]

Originally Posted by hyperasus

Holly crap. I am definitely going to buy some of these for my E-Revo. No cuttoff and no swelled packs sounds awesome to me. Don't get me wrong I will still keep my Lipos, but sometimes it feels like if I even look at my Lipo packs wrong they swell up on me.

Keep in mind they are 13.2v vs 14.8v so top speed will be a touch lower (no loss in torque though) and you will get less than 12minutes run time on any brushless setup (unless you drive like a grandma of course). 2300mAH doesn't last long... for me I have a Truggy that is pulling near 300mAH per minute racing so those packs would last me 7.6-8 minutes max.. just enough for a qualifier, but I have to loose top speed to run them - not ideal. My erevo pulls a little less mAH per minute so my particular setup would yeild a run time closer to 10minutes.

[hyperasus]

I agree that at the moment A123 cells are hopeless for racing because of their weight to capacity ratio. But I have no races in my area so my toys are 100% built for bashing.

The A123 4600mAh 2S2P, and the 2300mAh 4s1p are 135mm x 55mm x 28mm

The E-Revo battery compartment is said to be 156mm X 50mm X 29mm

So only 5mm too wide gives me hope. There has to be a way. Then I could run as 2300mAh 4 cell, which would give my truck plenty of nards. Not sure what the run times would be but if I could squeeze 15 to 20 minutes of good bashing it would be good enough for me. I don't think I've ever drove my E-Revo for longer then 20 minutes in a single run so I'm willing to bet I wouldn't miss all those extra mAh.

[JThiessen]

The 4600 2S2P's are going to be about 1/2" too wide for the compartments on an E-Revo. I did a physical check on that with my batteries.

On my converted Revo, running an HV-4.5, I would get 20-25 minutes bashing time out of a pair of those batteries. And twenty minutes later, they were fully charged and ready to go.

[hyperasus]

Any aftermarket chassis for the E-Revo that will use all the stock trannys and drive shaft? This battery tray limitation is getting old already.

[JThiessen]

G-Maxx chassis with a 3906 Emaxx tranny.

[hoovhartid]

Originally Posted by hyperasus

Any aftermarket chassis for the E-Revo that will use all the stock trannys and drive shaft? This battery tray limitation is getting old already.

what about the kershaw designs one?

http://home.ptd.net/~kershawd/Kersha...vo-Chassis.htm

Originally Posted by hyperasus

I agree that at the moment A123 cells are hopeless for racing because of their weight to capacity ratio. But I have no races in my area so my toys are 100% built for bashing.

The A123 4600mAh 2S2P, and the 2300mAh 4s1p are 135mm x 55mm x 28mm

The E-Revo battery compartment is said to be 156mm X 50mm X 29mm

So only 5mm too wide gives me hope. There has to be a way. Then I could run as 2300mAh 4 cell, which would give my truck plenty of nards. Not sure what the run times would be but if I could squeeze 15 to 20 minutes of good bashing it would be good enough for me. I don't think I've ever drove my E-Revo for longer then 20 minutes in a single run so I'm willing to bet I wouldn't miss all those extra mAh.

For racing longer than 15 minutes at a time lipo is probably the only way to go. For playing around and practicing a123 charge rates can't be beat for max time on the track without having a supply of lipos batteries and two chargers to keep you going.

I go to the local tracks with only 2 3s a123 packs. One charged 3s a123 pack, and one run down form the last outing. I plug the run down battery in to a 9 amp 12v computer power supply and it charges up in 15 minutes. Thats how long a charge lasts in my rustler anyhow. Swap the batteries and repeat. Just a couple minutes of down time while swapping the batteries before I am running the car again.

I picked up an 18 amp 12v power supply today so my charging time can now be less 8 minutes per 3s pack. 18 amps is above the 4c standard charge rate for a123 but others have been doing this for 100s of cycles with no significant decline in capacity/performance. You could charge two 3s packs at a time in parallel in just over 16 minutes.

Keep in mind if you use 3s packs you can use a computer power supply and a voltage cutoff device ($15 diy kit or $40 completed unit) and have a nice way to charge 3s packs quickly. With 4s you will need to get a high amp charger but then I think 10 amps is about the limit still and price goes up considerably too.

[BL_RV0]

What charger did you buy?

I meant to write power supply, so I changed it above. Its just an atx computer power supply...

[hyperasus]

Originally Posted by hoovhartid

what about the kershaw designs one?

http://home.ptd.net/~kershawd/Kersha...vo-Chassis.htm

Two thumbs up. Exactly what I was looking for. I am going to get 2 of these coming for my E-Revo and G3R.

I see maxamps and hobbyking are selling flat life packs -

9.9v 4500 packs:

$180 from maxamps
$40 from hobbyking

http://www.maxamps.com/categories.php?cat=223

http://hobbyking.com/hobbycity/store...8&ParentCat=85


Have not tried them myself and won't be paying that much for a maxamps pack, but for $40 I may just want to try a pack from hobbyking.

[JThiessen]

Yeah, probably well worth experimenting with. Look big and a little heavy - but at the price, might be well worth it. Wonder if the flats will charge as fast as the genuine A123's?

[BL_RV0]

That hobbycity 6s pack does look interesting, but it is hefty at 900g!

[Unsullied_Spy]

Originally Posted by BL_RV0

That hobbycity 6s pack does look interesting, but it is hefty at 900g!

Not to mention huge. Gotta tow a trailer behind your RC just to haul the battery around.

[scarletboa]

Originally Posted by chadr

I see maxamps and hobbyking are selling flat life packs -

9.9v 4500 packs:

$180 from maxamps
$40 from hobbyking

http://www.maxamps.com/categories.php?cat=223

http://hobbyking.com/hobbycity/store...8&ParentCat=85


Have not tried them myself and won't be paying that much for a maxamps pack, but for $40 I may just want to try a pack from hobbyking.

i wouldn't be surprised if they were the exact same cells. the dimensions are all the same. the ratings aren't though. i wonder why...