I think there has been some great advice so far but the first fundamental question has not been answered and for those with experience I will restate it.
For those of you with shore power, a charging inverter
, charging indicator, a voltmeter and an ammeter -
1 - Do you normally see short term fluctuations in charging rate?
2 - Do you see the battery power drop to 75% then climb back to 90+% over time?
Shibbershabber - I don't have such a system but the first step for me is to monitor
it over time. I would not be concerned at this point unless the battery power dropped below 60%
While monitoring I would be looking for the fluctuations you describe. My premise is that the system is cycling and in my mind it shouldn't be cycling that much. The troubleshooting when you get to it is to determine why it is cycling.
1 - It's normal - the charge system is set up to discharge to a certain point and then recharge
2 - It's not normal - something is supposed to be sensing current
draw and is not sensing it properly - i.e. there is a charging system problem
3 - The battery bank has a problem - low water, high resistance, some other intermittent fault or problem.
4 - There is a shore power system intermittent problem.
Part 2 is an educational exercise. I would search the internet
and the docs that came with the boat for manuals
on the equipment
you have. Then I would read the manuals
cover to cover and try and work out how the system should behave. If you didn't understand things in the manuals I would post questions here.
What you end up with is a pretty good education about how your electrical system
works on your boat.
things described above are not bad things to do and many of them fall into the category of preventative maintenance
- top up lead acid batteries
- disassemble, check, clean and reassemble the battery connections
I also generally agree to do the simple things first but it should be blended with experience. You can sink a lot of dry holes but shotgun troubleshooting and waste a lot of time.