Re: Prof. Sommer's Controller Review [TANKS]

[Frank Pittelli <frank-at-rctankcombat.com>]

adt22-at-drexel.edu wrote:
> I've used a 9V battery for the relays.  It works, the problem is it
> only lasted about 20 minutes...

Relay coils pull anywhere from 200 mA (1/5 amp) to 1 amp depending on 
the make and model, so they can drain a little 9V pretty quickly.  I use 
the main 12V battery to control my relays, but any 12v gel cell would 
work as well.  A couple Amp hours should be fine.

        Frank P.