New Batteries?

[storm]

Ian, if your motors stall when your robot drives into the wall then something is VERY wrong ! You should be able to wheelspin.

What I suspect is happenning is that your batteries simply cant supply the current that your motors are asking. So yes they are drawing a maximum of 30 amps, but thats not the stall current of your motors, its that the batteries are limiting the performance of your robot as they cant supply enough current to do the business.

..... trust me Ian - I might *just* know what Im talking about.

Ed
http://www.stormrobot.comhttp://www.stormrobot.com

[ewan]

Ah, Eds got it right again!

[blazerbotics]

please note the just! The chance are your fuses are slow blow as well, so may peak above the 30amps. also your motors are drawing 30amps each, therefore 60 when stalled.

[craig_anto]

no comment

[mute]

Have to agree with Ed here, by the sound of it your batteries aint kicking out enough current to stall your motors.

Micro Mute used to run two NCC-70 speedos on its motors, and we unfortunately current limited at the batteries. MM could easily draw well over 100A per motor (yes they were BIG motors), however the battery could only give out 100A max.

Dont rely on batteries current limiting because in a 5 minute fight they get VERY VERY HOT.... we lost 2x 24V 2.4Ah NiCad packs to over heating.

Micro Mute - the one and only battery cooker

What good is all that power when you carnt stop before you hit a wall?

regards
Dave moulds
Team Turbine

[blazerbotics]

in micro mutes case, in the pit!

[jamesb]

had a custom made LiPo made for one of mine by a company that leads the world in the technology, and sent direct from Korea, but it never arrived.
been on to them and apparently its not safe to ship the way I wanted it (ie, cheap) in case it is knocked and cracked, it will explode....
asked how this is ok for robots and they seemed to confuse robot fighting with robot stangin there looking nice but doing nothing.

current, is limited by the size of cell, if you want more current get bigger cells, that was my plan, and I could have 45amp for 5 minutes (comprable to NiCDs we use in feathers). had to have special cell made, but is possible.

price, if youve got it flaunt it, if you havent... well.

at the end of the day, do what you want, but no offence to people who may show up with these in future, if you have a LiPo in your feather, dont expect me to allow you to run. Dont like exploding robots, and dont fancy wasting my fire extinguishers on a dead cert bonfire.

for now, ants seem ok, but until they can protect these lipos, I cant see them being safe.

BTW, arent they used a lot for electric flight with high current, high performance motors? Sounds like they can produce some useable power.

My batt sponsor (http://www.countybattery.comwww.countybattery.com) has every type of battery you could imagine, exept Li-Po. They store their batteries in an air-conditioned warehouse and carry them around in or on crates by forklift truck. If a single small pack fell off a forklift truck,then boom! You could imagine a heavyweight bot with VERY large Li-Po cells come up against Storm II. The forces involved would almost definately leave the packs ending up in smoke...
Cheers, Ewan