3 x 24v nicad packs

[typhoon_driver]

*face palm* You can only use 30 nicad cells in series max. This results in 36v (1.2v per cell)

Don't even think about mixing battery types either to get more voltage!!!! A bunch of used nicads will get hammered if put in series with lipo.

You can't get 72v using the cell numbers you are allowed to use

Easy with the optipower discount to get lipo at that cost. I wouldn't bother with the turnigy nano tech. They can't deliver what they promise (as ever)

[Bacon Wizard]

You can't get 72v using the cell numbers you are allowed to use

Bugger, back to possible capacitor banks then. Anyway, let's get off the For Sale thread.

[typhoon_driver]

Just make sure you have a method of safely discharging them. I don't think there is any mention in the rules about capacitors but the size you would need would substantial and could give a severe shock either to you or to the arena marshalls (might want to check with event organisers that they would be happy with capacitors)

[typhoon_driver]

But you aren't allowed a 72v battery pack in the rules and he has already stated that the motor would be over volted so it wouldn't be within specification.

[Bacon Wizard]

6.6 Voltages
Voltage must not exceed 75V for direct current or 50V for alternating current except where prior approval
from the event organisers has been confirmed.

I am unclear on the number of cells permitted actually. Yes, it's 30 for NiCad, but the way it's worded implies that's only when in series. ie, could have more in parallel. And yes I know only series will increase voltage...

[typhoon_driver]

Only 30 cells in series. You can parallel them up no bother to increase capacity

[kane]

6.6 Voltages
Voltage must not exceed 75V for direct current or 50V for alternating current except where prior approval from the event organisers has been confirmed. Note that batteries may have a higher voltage during charging and care must be taken not to exceed these limits.

7.5 Maximum Cell Count (series) and voltage

7.6 Parallel CellsBatteries cells may be connected in parallel to increase capacity and discharge current. Caution must be taken with NiCd and NiMH as these cells may only be connected in parallel during discharge.

This indeed means that you could use 2 packs of 30 cell NiCds in parallel (total 60 cells). But you could not connect in series.

[Bacon Wizard]

Lovely, Tah!