hw batteries

[Max]

Hi,
I'm after some batteries for my new hw, I am looking to run 2 Bosch 400s on 18v. Current options are Turnigy Lipos from hobbyking or possibly some cheap 6v SLAs from Component shop but I doubt they would offer much discharge.
So does anyone have any second hand or uneeded batteries they want to part with? Any cell type considered but obviously need to be in good enough condition that they work and hold their charge.
Thanks,
Max

[psycho_fling]

Might be selling some 12v sla batteries soon - will only be sure in a few weeks though

[typhoon_driver]

got some 12v 13ah hawker odyssey batteries that I could be convinced to part with. They aren't in brand new spec but still held a charge last time I used em.

[Max]

I am tempted by the hawkers but the problem is I can't get the 18v from them without something like a transformer. I could just use the boschs on 12v but then I feel I am basically left with wheelchair motor power and it will all be a bit pathetic
I could make it 24v then use the travel adjusts to stop the motors seeing more than 18v bit then its a waste of weight having 24v batteries.
I presume there is no way of separating Hawkers to get 2 6v packs like you can do with Nicds or Nimhs?

[kane]

The hawkers would be a good bet. Run at 12v with a good gear reduction, you don't need speed in the arena and the voltage sag drawing so much current at 18v (or even 24v) will loose you loads of power anyway. A good torque'y drivechain, then when you upgrade later you can just turn the voltage up with a nice set of OptiPower LiPos.

[typhoon_driver]

Well if you want I'll have a check of the hawkers and I'm sure we can come to an agreement on price etc

[Max]

I'm still after a set of batteries- 18v or 12v.
If I can't get any second hand ones what do you think of using these:
http://www.optipower.co.uk/Catalogue...20PACK&cat=131
I think a pair of those should be able to supply plenty of amps to run the motors at 18v? But saying that I only have a Vantec 47e so can only supply 75A continuous so do you think I have to go for 12v?

[maddox10]

I'm still after a set of batteries- 18v or 12v.
If I can't get any second hand ones what do you think of using Optipower 4300mAh 5S packs.
I think a pair of those should be able to supply plenty of amps to run the motors at 18v?

Those should do nicely. But ain't it a lot cheaper to buy 3 6V SLA batteries then?

But saying that I only have a Vantec 47e so can only supply 75A continuous so do you think I have to go for 12v?

Length of a fight. 5 minutes. Even taking in account you don't want to drain a Lipo pack below 35%, that means you can draw 67 amps continue for the 5 minutes.

[Max]

Still looking for batteries, if anyone going to Guilford has some they want to part with please let me know. Again, looking for any cell type either 6,12 or 18v.
Thanks,
Max

[Max]

I could use 3 of these:
http://www.componentshop.co.uk/6v-9-0ah.html
That way if they draw too much current on 18v its easy to switch to 12v. But then I'd have to buy a set for each battle as there's not time for charging. How many battles does each robot have at an event on average?
The alternative I was thinking of was using a pair of 4s 30c 5000mah optipower lipos, hopefully I'd have time to charge them between battles. They would cost £90 for the pair.