Re: My Alternator is Charging!
Reply #1 –
Depends on the state of charge your AGM batteries have now. Also depends where the voltage reading is coming from, is it the stock analog gauge or a digital? Would suggest you take a digital meter and read the voltage AT the batteries with the engine running but AFTER the batteries are fully charged. Go online and find the manufacturer of your battery. They will have the normal range of voltages for that battery. Important that the final float/maintenance voltage be right around their specifications for maximum battery life while on shore or solar power.
Because of the battery isolator (isolates the house from the engine batteries), alternator voltage will be higher than the reading at the batteries.
Most automotive and aircraft equipment is designed to operate at about 13.8 volts with a full charge a few minutes after shutting down of 12.7 volts. For a super accurate reading, some manufacturers recommend waiting 6 hours after charging for a final check.
Quote:
"The BULK stage involves about 80% of the recharge, wherein the charger current is held constant (in a constant current charger), and voltage increases. The properly sized charger will give the battery as much current as it will accept up to charger capacity (25% of battery capacity in amp hours), and not raise a wet battery over 125° F, or an AGM or GEL (valve regulated) battery over 100° F.
The ABSORPTION stage (the remaining 20%, approximately) has the charger holding the voltage at the charger's absorption voltage (between 14.1 VDC and 14.8 VDC, depending on charger set points) and decreasing the current until the battery is fully charged. Some charger manufacturers call this absorption stage an equalization stage. We don't agree with this use of the term. If the battery won't hold a charge, or the current does not drop after the expected recharge time, the battery may have some permanent sulphation.
The FLOAT stage is where the charge voltage is reduced to between 13.0 VDC and 13.8 VDC and held constant, while the current is reduced to less than 1% of battery capacity. This mode can be used to maintain a fully charged battery indefinitely."
Important with AGM batteries that your shore or solar controller/charger does not include an equalization period in the charging process as most manufacturers don't recommend it for AGM. Can reduce battery life. This is programmable on newer chargers. Should be addressed at the web site.
Pierce
Topic: My Alternator is Charging!