Battery question, opinions needed
I have two battery banks on my 5th wheel that I can switch on and off or use both. Bank 1 has 4 deep cycle batteries and is used when boondocking. Bank 2 has one 12v deep cycle battery and is used pri...
Forum Discussion
Thanks everyone for the very helpful input. The whole thing turned into a Murphy's law experience. I bought the new batteries online at the closest Walmart 80 miles away. Everything was confirmed for curbside pickup in 3 hrs. Somehow they screwed up the order so bad that my debit card got flagged for fraud. Bank said it was their fault. Took 2 hours to fix the card issue. Then walmart "said" they didn't have the batteries. Had to go to a Walmart an extra 25 miles away. So 210 miles round trip.
I was concerned that maybe an overcharging alternator might have caused the battery problem. But I couldn't test that until the new batteries went in. The battery install was easy. Fired it up. Check engine light came on. It was running fine but charging at over 15 volts. One of the trouble codes was a probable faulty ECM which would have been a $2,000+ dealer only repair.
It was late in the day. I decided to sleep on it. Started watching YouTube videos instead. Among other things, I learned that the ECM regulates the charge from the alternator. It will go over 15 volts if temp is freezing or below. It was 30° and dropping when I started it with new batteries. Eventually I came up with this extremely hopeful theory that the multiple trouble codes resulted mainly from the bad battery (it could have easily been the other way around). I couldn't get hold of my mechanic, so I deleted the codes and went for a long test drive the next day after it warmed up to 45°.
Apparently, the theory I derived from over a dozen videos was correct. The trouble codes didn't come back, charging was below 15 volts, and it all held up during a long test drive. Hopefully that all holds firm and we're off to our next park tomorrow. Yay.
Btw, if you don't have one, get a battery tester. Topdon makes some really good ones for under $60. I got mine on eBay for $23. It measures CCA, internal resistance, SOC, etc. It also tests your alternator and starter. The cheaper one I got assumes you have some knowledge. The midrange ones do the same thing but assume you're a novice. The expensive ones do pretty much the same thing, but they give a printout of results for your customers. Also, battery maintainers have gotten cheap. I got the Sigma 1 for under $30. Both of these devices are light-years ahead of anything I thought I'd ever own. Heck, the code reader I have works on every car manufactured since 1996. It's now about $15. I think I paid $50 when I bought it a few years back. These and other newer electronic tools make the RV life so much easier. All of mine together cost under $200 today. I easily saved more than that on just this problem.
I was concerned that maybe an overcharging alternator might have caused the battery problem. But I couldn't test that until the new batteries went in. The battery install was easy. Fired it up. Check engine light came on. It was running fine but charging at over 15 volts. One of the trouble codes was a probable faulty ECM which would have been a $2,000+ dealer only repair.
It was late in the day. I decided to sleep on it. Started watching YouTube videos instead. Among other things, I learned that the ECM regulates the charge from the alternator. It will go over 15 volts if temp is freezing or below. It was 30° and dropping when I started it with new batteries. Eventually I came up with this extremely hopeful theory that the multiple trouble codes resulted mainly from the bad battery (it could have easily been the other way around). I couldn't get hold of my mechanic, so I deleted the codes and went for a long test drive the next day after it warmed up to 45°.
Apparently, the theory I derived from over a dozen videos was correct. The trouble codes didn't come back, charging was below 15 volts, and it all held up during a long test drive. Hopefully that all holds firm and we're off to our next park tomorrow. Yay.
Btw, if you don't have one, get a battery tester. Topdon makes some really good ones for under $60. I got mine on eBay for $23. It measures CCA, internal resistance, SOC, etc. It also tests your alternator and starter. The cheaper one I got assumes you have some knowledge. The midrange ones do the same thing but assume you're a novice. The expensive ones do pretty much the same thing, but they give a printout of results for your customers. Also, battery maintainers have gotten cheap. I got the Sigma 1 for under $30. Both of these devices are light-years ahead of anything I thought I'd ever own. Heck, the code reader I have works on every car manufactured since 1996. It's now about $15. I think I paid $50 when I bought it a few years back. These and other newer electronic tools make the RV life so much easier. All of mine together cost under $200 today. I easily saved more than that on just this problem.
