3 x 24v nicad packs

[robotwars]

Looking at going to a123's in the new ripper, so selling all my spare nicads

As the title says ..

3 x 24v nicads really good condition.

£150

[terry]

Knew you would change eventually :-D

[robotwars]

Only because I'm building a new one :-)

[robotwars]

The batteries have now sold.

[Bacon Wizard]

Gazumped

[Bacon Wizard]

NOT gazumped!

[typhoon_driver]

I would have just bought a set of lipo at the same price. Better discharge too

[Max]

I would have just bought a set of lipo at the same price. Better discharge too

You'd struggle to get 3 decent 6s for that price. By the way Gary, would you recomend the lipos you used in Boner for a hw or I the true discharge not enough?

[Bacon Wizard]

Long term, I would like A123s, but these will do nicely to get me up and running.

I checked prices quite carefully before committing, and this solves how to get 72v out of the max permitted number of LiPo or LiFe cells. How else am I gonna over-volt my 10hp motor? eh? EH?

[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)

[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...