weird question that came up today

[Andy L]

Is it possible to use 2 batteries to power a robot?

we were just thinking about it today and didn't know the answer

[sanddrag]

Possible? Yes. Legal in FIRST? No.

[lenergyrlah]

<R46>

Items specifically PROHIBITED from use on the robot during competition matches include:
 More than one primary battery, or more than one back-up battery.

This is only part of the rule (other things are also prohibited).

[Andy L]

i know it isn't legal i was jsut wondering how

[Taylor]

It's legal and it's recommended.





provided one of the batteries is a backup.

[lenergyrlah]

I think he meant two 12V batteries

[Brian C]

If your questions is "How?" the answer is pretty much that you can wire them in either serial or parallel.

If you wire them in parallel you will still have 12 volts but twice as much current available. This may also mean larger conductors of you plan on drawing that current quickly. If you did this in your currrent robot configuration now it would basically extend your run time to approximately double.

By wiring them in series you will get 24 volts and about the same amount of current capability you have now. Obviously this would mean a change to any components that would be sensitive to this higher voltage.

[meatmanek]

Originally Posted by Brian C

By wiring them in series you will get 24 volts and about the same amount of current capability you have now. Obviously this would mean a change to any components that would be sensitive to this higher voltage.

Just to make this clear, he means DON'T DO THIS unless you replace all of the electronics with something that can handle 24 volts. Doubling your voltage is a good way to fry stuff.

Hooking 2 batteries in parallel would be a good idea for the old show robots. It's a pain to have to change the batteries every 5 minutes

[Andy L]

how do you wire them in Parralel(sp)

[Scott team 48]

To wire in parallel you just run a wire from the positive of one battery to the positive of the other, and then to the positive end of your Anderson connector. Do the same for the negative.

[Adam Richards]

Originally Posted by Scott team 48

To wire in parallel you just run a wire from the positive of one battery to the positive of the other, and then to the positive end of your Anderson connector. Do the same for the negative.

Or see this attached image from http://www.vdcelectronics.com:

[Cody Carey]

You can also just bolt another anderson connector on top of where the current one is attached to the main breaker and fuse block. Red to red, black to black. We did this for our t-shirt cannon because we were running two compressors, and it really helped.

[Andy L]

and then for future reference if I if i use two anderson connectors on a battery and plug one into bot and one into charger would i be able to plug it in and run without interruption?

[Jay H 237]

No, the FIRST provided chargers wouldn't keep up with the amount of current that most robots draw. This also makes the charger work harder too, as it's trying to charge the battery but the battery is being drained as it's charging. You would also have a tether now on the robot bringing up another problem driving around.

I would suggest getting an extra battery or two for demonstrations. We keep our old ones that are still good for this purpose. Even though they are illegal for comp they can be used inaddition to the current ones for demos. We just keep swapping them out as they weaken/die and rotating them with charged ones as the others get placed on chargers.

[ChrisMcK2186]

Wiring in series will fry all components sensitive enough. Can you place the ends of the two anderson connectors into the same holes/sockets in the fuse blocks, effectively creating a parallel circuit? Just a though, would it also increase battery life?

Chris