Hello,
I just recently acquired 2002 Gem 825 and it has 2 year old Interstate RV water batteries. My uncle could not get it to charge past 75% and I’m having same issues. It also drops charge rather quick.
After doing some research I did the following:
I trickle charged each battery and brought them up to 12.71/12.71/12.76 /12.75/ 12.74 and 12.56 volts on each battery and checked all water levels and they are all filled to proper levels.
I then plugged it in to have onboard charger kick on and do its thing and next morning it only charged to 80%.
I unplugged and replugged back in and the charger kicks on and starts to charge the batteries (you can hear it running). Then 1 hr later the charger kicks off and I then check the battery level on dash indicator and it is still 80%.
I then said to myself well I’ll take it for a drive to see how it holds charge, after about 3 miles I drop from 80% to 40%
What could be the main culprit here? I’m not too savvy when it comes to these but feel like I checked some of the easy things already, what am I missing? Could the charger be bad and it’s only giving batteries a surface charge and kicking off?
You are off to a great start!
Depending on where you are now, you may need to go through another charge cycle.
Then take it for a run and check all of your battery V again. This will give you a picture if one battery is taking a dive faster than the others. They should all travel up and down at the same rate.
Your pack is only as good as your weakest one.
You also should check with a load test.
Attach your meter on a battery and either take it for a drive, or do this via brake stand test. See how far each battery drops during load.
Report back with your findings.
Most likely this will lead to your batteries are getting old and in need of a swap. If you are lucky, you might replace one but that will be just a patch that will buy you a little more time.