TM Battery protection??

[arniland]

I finally put a new battery in our TM after abusing the old Group 27 one too many times. We are on an extended road trip, so I ended up at Wal-mart getting one of their Group 29's which is very close to the size of the one I replaced. I'll have to replace the box when I get home.

I would like to protect the batter from being fully drained by the fridge. Somewhere I think I've read about a device which turns off the battery when it reaches some predetermined level of discharge, 50% perhaps. I would rather do this and let the fridge just sit for a while if I end up away from the rig longer than expected, rather than have it damage the battery.

I've tried several search strategies, both here and on Google, but have only found very expensive commercial products.

Any ideas?

Thanks,

Arn

Originally Posted by arniland

I think I've read about a device which turns off the battery when it reaches some predetermined level of discharge, 50% perhaps. I would rather do this and let the fridge just sit for a while if I end up away from the rig longer than expected, rather than have it damage the battery.

My Xantrex LinkLite Battery Monitor has an output to power a relay and you can set the state of charge used to trigger the relay to whatever you want. I presume that a relay to isolate desired circuits such as the DC frig power would be a pretty cheap device (~$20?). The LinkLite itself isn't cheap (~200) but the data it provides is useful in and of itself. I don't know if LinkLite's competition from Clipper or TriMetric provide similar functionality, but in my mind a battery monitor is a very important piece of equipment. So I am suggesting that if you want to prevent killing a battery, get a battery monitor. At least one has a feature that could be used to do exactly what you want at minimal additional cost above buying the monitor.

[Barb&Tim]

Try a "low battery cutoff" search on google.

Tim