Join Date: Dec 2004
Thanked 57 Times in 57 Posts
Rep Power: 12
Barbara, the advice you got above is great. You probably already know that tracking down electrical problems requires a higher level of organization as the complexity of the system increases. Good plans and good record keeping as you make your way through the steps of the plan are important.
The first step I would take if all my equipment is relatively new and newly installed would be to check connections, especially those recently made, to make sure they are sound and tight and not overheating, especially crimped connections, which are frequently at fault.
Then, if I had not found my problem and I were you, I would strip every load from the system that I could by isolating them...make sure that both the ground and the power sides are interrupted. As this is done, keep that record mentioned above and check the connections being disconnected, making note if there are any that are "suspect" because the problem may be found as you do this. Especially note any connections that are hot or warm to the touch.
After isolating as many loads as practicable, split the charging and regulating equipment to isolate each one from the batteries. If it were me, I would disconnect and isolate both the wind and solar systems. Then I would use the engine/alternator or gen set if you have one to top up the battery banks, one at a time.
I would then start adding loads isolated earlier, one at a time, noting the system response using installed or portable volt and ammeters. Observe the voltage at the instant loads are started. Any that draw an unexpectedly high current will cause a larger than expected voltage drop on the battery bank. After checking a load, re-isolate it before moving to the next load. Continue to do this until all loads are evaluated. Re-charge the battery banks in use for this as required when their capacity is reduced to about half.
If I hadn't found the problem at this point, I would top up the batteries, and place one of the heavier loads that I have already checked on them. After the battery bank is discharged a bit, place the wind generator on the system, and evaluate its performance. Repeat for the solar charging system.
Barbara, it is late August, and temperatures in late August can cause fridges and freezers and coolers to run more than normal. You mentioned a couple of fridges as some of your heavier loads. Before I started troubleshooting anything, I would make sure the low voltages aren't due to higher cooling loads due to high ambient temperatures. Have you recently changed your shading plan for your boat (awnings, etc), or have the awnings been hung the same way, but the boat's heading (attitude relatively to sun) different, especially in the afternoons? Has the water temperature of the sea around you gone up appreciably? All these things can increase the loading on your systems radically.