a123s or lipo? again....

[zeropointbug]

Originally Posted by sl1

Hello all,
I am in the process of building a brushless CEN Matrix TR so I bought 2 dewalt 36v packs. I called A123 yesterday and talked to Brian and he said that he is getting 21min out of a 6S1P battery in an 8ight with a
Neu 1515-1Y and a MM combo on the track that tops out at 45mph. The amp draw peak was 40A in the 21min on the track. So I can't decide weather to try a 5S1P or a 5S2P in the truggy I figure that 30mph is fast enough for the track.

Yeah, 6s1p SHOULD allow the same power output as a 5s2p in a given vehicle, and a given motor choice... because the 6s1p will have higher voltage drop.

Right now, I am running a 7s1p pack in my Revo on Neu 1512, and I love it, it's light, it's powerful (~equivalent to 5.5s flightpower lipo), it has 15 min runtime, and i can charge the pack up in another 15 mins, it's great.

Tmaxxracer32... just go with A123's man and be done with it, enough of this.

[squeeforever]

Aqwut, personally, I think the TrueRC packs are his best bet. He can get a VERY good 4S2P 8000mah pack for $140 as apposed to $90 for a 5S2P 4600mah (I think?) A123 pack thats ALOT bigger and heavier.

[MetalMan]

5s2p A123 will be quite a bit larger than a True RC 4s2p 8000mah pack, but the weight difference will be about 70g, depending on how the 5s2p A123 pack is constructed.

[zeropointbug]

What DOD (depth of discharge) do people here discharge their lipo's to? % wise.

[highflier]

If you want maxx play time and it's not hard core competition the A123's are the way to go.

Make it a 6s2p pack... (12 cells)
For the 3 packs you listed that means you will have 6 cells left....
If you do your setup right you can charge the 6s2p pack in under 10-15 min. and the charging system is super cheap!!! Therefore you could run the remaining cells 6s1p. while the others charge. You will be a little heavier.. but with 6s2p there will be tons of power availible.

Now if you are going to the track to race, You'll want to shed the weight, and your run time requirements will be lower, So lipo's would be your best bet. You can pick up some charge between races and should have no issues with several races with a single pack.

I personally went the A123 route... but If I start going to the track I will get a set of lipo's to race with.

In Conclusion. Buy which ever matches your use plan.

Highflier

[t-maxxracer32]

Originally Posted by highflier

If you want maxx play time and it's not hard core competition the A123's are the way to go.

Make it a 6s2p pack... (12 cells)
For the 3 packs you listed that means you will have 6 cells left....
If you do your setup right you can charge the 6s2p pack in under 10-15 min. and the charging system is super cheap!!! Therefore you could run the remaining cells 6s1p. while the others charge. You will be a little heavier.. but with 6s2p there will be tons of power availible.

Now if you are going to the track to race, You'll want to shed the weight, and your run time requirements will be lower, So lipo's would be your best bet. You can pick up some charge between races and should have no issues with several races with a single pack.

I personally went the A123 route... but If I start going to the track I will get a set of lipo's to race with.

In Conclusion. Buy which ever matches your use plan.

Highflier

probably the best description for me....

you hit the spot with eevrything you said.

i am going to be racing this truck so it looks like lipos it is.

i may buy 2 dewalt packs just to have for when i go bashing.

thanks guys

[aqwut]

Originally Posted by squeeforever

Aqwut, personally, I think the TrueRC packs are his best bet. He can get a VERY good 4S2P 8000mah pack for $140 as apposed to $90 for a 5S2P 4600mah (I think?) A123 pack thats ALOT bigger and heavier.

Very true dude, but gotta love the power output.... the 5S2p would pump close to 2300 Watts where as the 4S2P TrueRC would only pump about 1200 watts.... and you could charge the A123s 3-4 times faster with the appropriate charger... but the TrueRC pack would last longer for sure...

[t-maxxracer32]

what would you say the lifespan of the a123 cells are?

and can you charge them at like 4c or something?

[aqwut]

Originally Posted by t-maxxracer32

what would you say the lifespan of the a123 cells are?

and can you charge them at like 4c or something?

I think it's about 2000 cycles... and upto 4C charging... you really can't go wrong with either lipo or a123 M1.. batteries are beautiful...

I'am very interest to make a 6s2p A123 for my 1/8 buggy for bashing session (because for racinc i've already a Flightpower 5000, 4s).

OK explain me three thing please.
First: wich charger can charge A123 cells? because i've a ICE charger and not sure if i can charge this A123.

Second: Must i balance A123 pack when charging? If yes, how could i make a plug to balance it?

Third: where can i buy it?

Thank you

[zeropointbug]

Originally Posted by aqwut

Very true dude, but gotta love the power output.... the 5S2p would pump close to 2300 Watts where as the 4S2P TrueRC would only pump about 1200 watts.... and you could charge the A123s 3-4 times faster with the appropriate charger... but the TrueRC pack would last longer for sure...

Which aspect of 'lasting longer' are you talking about? Life time, or runtime?

As for cycle life, no one knows yet... that's how awesome they are, I am getting close to 300 cycles now and have only lost 75mah in a 1p configuration. Impressive.

[offroader]

Originally Posted by david lamontagn

I'am very interest to make a 6s2p A123 for my 1/8 buggy for bashing session (because for racinc i've already a Flightpower 5000, 4s).

OK explain me three thing please.
First: wich charger can charge A123 cells? because i've a ICE charger and not sure if i can charge this A123.

Second: Must i balance A123 pack when charging? If yes, how could i make a plug to balance it?

Third: where can i buy it?

Thank you

Here's a link which shows you how to make your own balance plug for your A123 packs but I read somewhere these don't have to be balance. Can't find the site that had that write up.

http://www.rcgroups.com/forums/showthread.php?t=599316

[highflier]

Here is the real thread on how to charge the A123 cells fast
http://www.rcgroups.com/forums/showt...=8#post8593235

I charge them at 10+ amps. I start at 15+ and it tappers off as it goes.

You must use 3s or 6s packs though.

I balance them before and after the first few charges.. Then they are pretty good check them every now and them and you should be jsut fine. They take a good lickin and keep ticking.

Highflier

[t-maxxracer32]

that thread seems hard to follow highfligher

i got bored after just skimming through the first couple posts.

[nl12]

I would go with lipos Evo 30s are a great choice.