13 volt relay cutoff
13 volt relay cutoff
(OP)
I'm trying to find low draw circuit that will cutoff when a car battery dips to a less than perfect voltage. I had a one amp draw on my battery at all times which means if I don't drive every other day, its dead...
Even a 60 minute timer relay would do the trick.
Even a 60 minute timer relay would do the trick.





RE: 13 volt relay cutoff
In any case, I think I would find out where 1A is going rather than trying to make a temporary fix. If its not an amplifier or stereo then I would be somewhat concerned. What kind of vehicle is this, new or old?
RE: 13 volt relay cutoff
I know where the 1 amp goes, its my VHF APRS rig used for realtime vehicle location. It basically sqawks my GPS location every 30 minutes, every 1/4 mile or at every major turn. The radio, the gps and the modulator doesn't quite draw a full amp, but when it sqawks a 50 watt RF signal, that all adds up.
After a little thought, I may just use a second battery and a bridge rectifier (i.e. four diodes) to limit the current drain direction.
RE: 13 volt relay cutoff
Diodes would not be necessary if this GPS was tied to only this second battery. But still this battery will need to be charged and to use your onboard charging system will require the second battery be tied into the first battery. In order for the battery to get charged, you can not use diodes to block current flow. I would definately not look at a second battery. I do not see how diodes are going to help you in this situation at all.
RE: 13 volt relay cutoff
<nbucska@pcperipherals DOT com> subj: eng-tips
read FAQ240-1032
RE: 13 volt relay cutoff