Battery Charger and Battery Switch
I am ready to start my education on my battery charger. I have a starter battery and two house batteries - all 4D. I have a Guest 2530A charger. There is only one red light titled "DC Power Available."
The charger never shuts off. My house batteries were drained down to 4.3V the other night (that may be a different discussion), so I plugged in the charger and connected to one of the house battery terminals. It has been charging for 36 hours and still buzzing. Now, the panel voltmeter reads 13.7 or so. (And the switch is on house.) Handheld voltmeter reads 12.89.
First, why the difference in readings?
Is it supposed to stop buzzing? The charger says finished charge at 13.8V and it is there or very close according to panel voltmeter.
Is 36 hours an obscene amount of time to charge?
Can I check the water lever while it is charging?
The batteries don't feel hot and they are obviously not boiling over. Is it dangerous to keep charging them?
Wiring charger to the battery switch.
The negative is grounded - no problem there. Intuition tells me to wire the positive to the "Both" terminal on the battery. That way I could charge the starter batt or the house batts or both. The alternator feeds the starter, then to the "Both" terminal. But for some reason, during one of those half conversations with my mechanic, he said I should wire in to the "House" terminal so that I could charge the house or both.
What is the proper terminal on the battery switch for the battery charger?