Wanderlodge Question: electical problems

[Rob Robinson]

What type meter RMS or what????

2009/5/25 hippieforever3 <"debra@ticogps.com">

If you don't have them already, buy 2 tools. A clamp-on ammeter (best buy is a Sears one, under $100) and a good hygrometer.



Check the current draw using the clamp-on ammeter. Don't be surprised if it's about 5a when you think you have everything off. If its a lot higher, that's your first project. Find the current draw.



Next top off all battery cells and use a good charger to give them a full charge individually. Use a setting on the charger that has a cycle to at least 14.5 volts or equalize cycle.



After the individual charge, hook them all together and give them one more charge. Disconnect them and let them rest about an hour and then test voltages and each cell with a hygrometer. Voltage differences of more than 0.1v and hygrometer differences (see hygrometer instructions) mean bad or weak cells. With 4 - 12v batteries in parallel, there is no way to compensate for a bad cell. Get out the third tool (credit card) and buy some new batteries.



I spent 2 month screwing with a set of batteries that I had tested at 3 different battery shops on their automated testers as "good" before using this technique and finally fixing the problem with new batteries.



The automated battery testers are designed to test "cranking amps" and don't test the ability of batteries to "absorb" and store ampere hours.



If your generator or toad battery could use replacing, buy one that would work on the battery tray and use that new one for a reference while you are conducting the voltage and hygrometer tests. It's also really nice to have 5 of the same batteries because if one of the 4 gets a bad cell, you can sub in the 5th battery and still have a matched set, thus extenting the life of the set substantially.



BTW - I did find one other argument for using 6 volt batteries while doing all my battery de-bugging. If you have slightly mismatched cells you may be able to hook the 6 volt batteries up in a configuration where each 12 volt set is more closely matched to the other set(s). This will also extend useful life.



Regards,

--
Rob, Sue and Joey Robinson
94 WLWB