Brushless Thunder Tiger ST-1

[neweuser]

do you run LIPO??? Does that help with the cutting out when you run it in nimh mode, because mine does the same thing. It's like a thermal, but it's not in thermal mode....i give the brake a bump and i'm off, but it's frustrating.

[cart213]

No, I run the A123 li-ion cells. They do not require a voltage cutoff. The problem doesn't seem to be related to the type of cells used.

[neweuser]

Hmmm, interesting. Do you still have the cut out problem?

[cart213]

Yes. And it also happened after running at partial throttle, not just full throttle. It seems to happen more often when the truck is far away, maybe 200 ft. I use a Spektrum radio, though, so it should not be due to interference. My radio batteries are getting low, though. I'll try some fresh ones and see if that helps.

[neweuser]

I have the same problem with mine. I know it's not in thermal mode because the thermal led's don't come on, it still blinks red right? But the controller feels real cool????? I may try to reprogram mine......it only did it after a few runs....how about you?

[Serum]

Well, apparently you are not the only person with this problem..

Perhaps Mike can shed a light on this..

[cart213]

I think CHC said that he had the same problem. I've only used mine a few times, so I don't know if it is a programming issue.

[Rtsbasic]

Nice car man, looks like its definately not short of power.

How much did those A123 packs set you back?

[cart213]

The packs retail for $100 each, but I had a coupon and got them for $90 each.

I decided to ditch the turbos. I talked to A123Racing and they were great about it. They are giving me a credit for the turbos, and I'm getting another 2s2p battery for only $25. So look for an update in about a week on my truggy running 6s2p. :D Since a 6s li-ion is 19.8V, vs. a 6s lipo that is 22.2V, the Quark should not have a problem with my 6s like it seems to with other people's 6s lipos.

[aqwut]

cool.... I really want to try to batteries too....
nice and light... powerful.. Have you tried charging them at 3C yet?... if so, how did it go?

[cart213]

A123Racing makes a special charger just for these batteries. It is fully automatic; just plug the battery to the charger and let it go. It has a max. current of 10A, so it can only charge my 2s2p batteries at 2C. It can charge the 2s1p batteries at 4C, though.

[aqwut]

very cool...
I need 2 4S2p batteries.. and 4 chargers.... :)

[Serum]

They are quite expensive imo. they don't deliver too impressive number either?

[cart213]

They are not that expensive next to a comparable top-of-the-line lipo, but they are expensive compared to a middle-line lipo such as Maxamps. Check out the stats below.

Compared to the Maxamps, the A123 has an advantage in capacity, current rating, and charging. Maxamps has an advantage in voltage, cost, and weight.

Compared to the Trakpower, the A123 has an advantage in cost, current rating, and charging. Trakpower has an advantage in voltage, capacity, and weight.

Maxamps 4200 2s2p (7.4V)
$77
201g
60A const. (15C)
80A burst (20C)
1C charging
$10.40/volt

Trakpower 4900 2s1p (7.4V)
$125
268g
98A cont. (20C)
147A sustained (30C)
245A burst (50C)
1C charging
$16.89/volt

A123 4600 2s2p (6.6V)
$100
310g
138A cont. (30C)
276A burst (60C)
2C charging
$15.15/volt

The biggest disadvantage of A123 (imo) is the lower voltage rating. However, this can be overcome by increasing the pinion size, as demonstrated by Mike and Batfish.

The biggest advantage of the A123 (imo) is the safety and durability. To be honest, I am lazy with the care of my batteries. I leave them in my car, my garage, and my desk at work, and I don't like to monitor them during charging. I wouldn't feel comfortable treating lipos this way, so I'd rather pay a few dollars more for the extra peace of mind.

[Serum]

but what is the voltage at the 60C bursts? i can't imagine it wil be any higher than 2 volts per cell? (if not lower)