9.6v NiMH R/C car batteries for pedal board?

[therecordingart]

I'm considering buying a couple of R/C car batteries to power a pedal board. One of my concerns is lifetime between charges. Back in my teen years I used to run R/C cars, and the battery life was terrible, but those cars consume a hell of a lot more juice than a pedal board would.

Anyone done this? Bad idea?

[jefe]

I can't think of a reason why it wouldn't work.

Search the site for "motorcycle battery", you might find some pointers.

[Heemis]

Upon a quick look up of a 9.6v RC car battery, I noticed the battery has a 3400mAh rating.  That would certainly power most analog circuits for quite a while, digital a bit less, but compare that capacity to a typical 9v battery ~500mAh.  Rig it up!

[Ice-9]

I have used RC racing packs in the past, they will last a long time on a pedal board. The RC motors that these packs usually power can draw about 60 amps from the battery, thats a huge amount compared to the ma pedals use. Go for it.

[JKowalski]

It's pretty easy to determine how long they will last.

mAh = milliamp * hours = how many milliamps it can supply for an hour.

If your pedal board only draws say 500 mA...

3400 mAh = 500mA * x h

Solve for x, that's 6.8 hours.

The RC car might draw 6 amps or so (taken from a random internet search) so thats

3400 mAh = 6000mA * x h

~0.56 h, or 33.6 minutes.

Of course those are all ideal calculations, and probably very optimistic. There are probably all kinds of factors such as how the battery behaves with low capacity (series resistance blah blah) how the battery holds a charge after repeated charging, how much leakage there is in the battery, etc. that will limit the useful runtime of the battery.


I was thinking about doing something similar, but I don't know how useful it would be - I mean, if you are playing a gig, you are bound to have an outlet somewhere... Unless you rig up a rack of car batteries and inverters for your amps.....  Even then, wouldn't you just run the pedal board of of THOSE batteries?

In any case, I would suggest you simply wire up the pedalboard so that you can plug it into a power strip and it charges the battery while you run the board off of wall power. Unplug and your battery keeps it goin.

[Hides-His-Eyes]

I have problems at gigs with filthy power supply outlets shared with the lighting, on different loops to the amps/backline... I think if I gig again I will just take batteries. That and set up a global bypass switch... I dunno. I just worry about problems I've had before.