Inverter issues

I've never seen a magnum like that...

Regardless, you need to check each cell of your house batteries. Pretty sure you have a shorted cell.

Isolate the batteries, turn off the inverter charger, disconnect the big red wire, unplag from shore power. isolate them and let them rest for a half hour or so.

Take the fill caps off.

Check each cell with a voltmeter. first, neg on neg terminal, positive in the liquid in the nearest cell.

second voltmeter leads in the liquid of the first and second cell. and so on down the line, check each cell individually.

Each cell should read right around 1.6 volts.

A shorted cell will read much less.

I wonder if you will get a good Load Test at AutoZone for Golf Cart storage batteries.

AutoZone and other auto part stores focus on Starting battery load testing. I think that is a big load for a short period of time.

At six years and with ongoing battery problems, you may need to change the batteries for new ones to solve the problem.

Did your batteries test good? mine are still coming in at 13.6 when tested.

13.6V means your charger is in float mode and doesn't mean the batteries are any good. A fully charged battery at rest will be 12.7V. Did the auto store do a load test?

Have you load tested the chassis battery as that is another issue. You should be able to park the rig for say a month with no chassis battery issues.

With the charger working again - Chassis battery charge test: Turn on the headlights for 5 minutes to drop the voltage a bit. Plug the rig in and check the chassis battery voltage. Wait a few minutes and if 13.2V+ then it's being charged.

I have now retrieved the type of inverter I have, It is a Magnum Series, model-MM 1212 model# M1-00535

rgatijnet1 wrote:

brianseay1 wrote:

CA Traveler wrote:
BTW From a safety point you always remove the negative cables first. If you don't and short the positive terminal to ground nasty things can happen. Then remove the Magnum cable and restore all cables.

BTW The first thing you should have done before wrenching was to take pictures so that you can verify the re-connections.

I did take pictures before removal, That is why I know they are correct. Nothing has changed in the inverter as far as settings go. That's what has got me stumped. I had noticed that the last couple of times that my batteries were not charging fully. Thought that I may have been leaving something on and running them down. Last trip out I had to use emergency battery to start engine. Had to do it the same way yesterday to start engine, that is what got me started to thinking I had bad batteries and now it has just snowballed into bigger issues.

I am not sure how your inverter is set up but mine DOES NOT charge the chassis batteries. It only charges the house batteries.
If you had trouble starting your coach, that indicates that your chassis battery is discharging or bad, and may be a separate problem from your house batteries overcharging. A chassis battery discharging rapidly could also be a mirror heat switch left on or any number of items left to draw power.

I can't say honestly if mine charges chassis batteries either. The manual is not very clear on this. Not very good on electrical issues. The chassis batteries test good as well. I hate issues like this, because I have no real good idea on what to look for. I appreciate everyone's help on what to look for. that is a BIG help.

brianseay1 wrote:

CA Traveler wrote:
BTW From a safety point you always remove the negative cables first. If you don't and short the positive terminal to ground nasty things can happen. Then remove the Magnum cable and restore all cables.

BTW The first thing you should have done before wrenching was to take pictures so that you can verify the re-connections.

I did take pictures before removal, That is why I know they are correct. Nothing has changed in the inverter as far as settings go. That's what has got me stumped. I had noticed that the last couple of times that my batteries were not charging fully. Thought that I may have been leaving something on and running them down. Last trip out I had to use emergency battery to start engine. Had to do it the same way yesterday to start engine, that is what got me started to thinking I had bad batteries and now it has just snowballed into bigger issues.

I am not sure how your inverter is set up but mine DOES NOT charge the chassis batteries. It only charges the house batteries.
If you had trouble starting your coach, that indicates that your chassis battery is discharging or bad, and may be a separate problem from your house batteries overcharging. A chassis battery discharging rapidly could also be a mirror heat switch left on or any number of items left to draw power.

brianseay1 wrote:

debandi wrote:
I don't have your converter but I had a similar problem. I was putting nearly 1 gallon of distilled water in the batteries a week because one of the batteries had an internal short. I've replaced the 4 batteries and am keeping an eye on the water level. Things are all good now. Lesson learned is to keep an eye on the water level in the batteries.

Did your batteries test good? mine are still coming in at 13.6 when tested.

My batteries are 6 yrs old. they are the ones that came on the coach when I bought it in 2009. I am assuming they have never been changed.

debandi wrote:
I don't have your converter but I had a similar problem. I was putting nearly 1 gallon of distilled water in the batteries a week because one of the batteries had an internal short. I've replaced the 4 batteries and am keeping an eye on the water level. Things are all good now. Lesson learned is to keep an eye on the water level in the batteries.

Did your batteries test good? mine are still coming in at 13.6 when tested.

CA Traveler wrote:
BTW From a safety point you always remove the negative cables first. If you don't and short the positive terminal to ground nasty things can happen. Then remove the Magnum cable and restore all cables.

BTW The first thing you should have done before wrenching was to take pictures so that you can verify the re-connections.

I did take pictures before removal, That is why I know they are correct. Nothing has changed in the inverter as far as settings go. That's what has got me stumped. I had noticed that the last couple of times that my batteries were not charging fully. Thought that I may have been leaving something on and running them down. Last trip out I had to use emergency battery to start engine. Had to do it the same way yesterday to start engine, that is what got me started to thinking I had bad batteries and now it has just snowballed into bigger issues.

I don't have your converter but I had a similar problem. I was putting nearly 1 gallon of distilled water in the batteries a week because one of the batteries had an internal short. I've replaced the 4 batteries and am keeping an eye on the water level. Things are all good now. Lesson learned is to keep an eye on the water level in the batteries.