3 x 24v nicad packs

[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)

[craig_colliass]

If you have a 72V motor and can demonstrate the battery pack is compatible to the motor spec,
All associated wiring has capacity to spare and you have complied with all the safety rules, Locking bar, link etc.
I don’t think the EO would have as much a problem with this. As a bank of capacitors ready to,

“Cry havoc and let slip the dogs of war."

[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!