Deep Cycle Battery Charging From Alternator
Hello, May I ask for advice regarding charging deep cycle batteries from the alternator? I have read older threads, and understand opinions vary. The previous two 100Ah deep cycle AGM coach bat...
Forum Discussion
Your problem is that you're drawing down the batteries too much. Rule of thumb for any lead acid battery is to never discharge below 50%. Your fridges alone need 120 amp hours a day. I would imagine your actual use is closer to 200-220 amp hours per day. Realistically you need 400+ amp hours of battery capacity and at least 400 watts of solar to replenish that or to be able to run a generator 5+ hours a day.
I would install at least 4, and perhaps 6, GC2 style golf cart batteries. Four will get you 215x2= 430 amp hours which gets you at approximately 50% discharge per day. There are AGMs available if you desire, they cost more. I haven't had to put any water in my batteries at all in the last 5 months, but you do need to be able to check them. 400 watts of solar will replenish about 25 amp hours per hour of full sun (assuming 80% of the 400 watt capability), which will require 8-9 hours of sun per day to replenish your daily use. If you think you're going somewhere where you'll have cloudy days, consider more battery capacity.
You should plan to have enough capacity from your solar and batteries to cover your use. That way whatever the alternator or inverter gives is just a bonus.
Note that solar isn't the only way to accomplish this but ultimately, your problem is that your storage tanks (batteries) are too small for what you're trying to do. That is why they had short life and I bet pitiful performance. Honestly I'm surprised they lasted as long as they did.
I would install at least 4, and perhaps 6, GC2 style golf cart batteries. Four will get you 215x2= 430 amp hours which gets you at approximately 50% discharge per day. There are AGMs available if you desire, they cost more. I haven't had to put any water in my batteries at all in the last 5 months, but you do need to be able to check them. 400 watts of solar will replenish about 25 amp hours per hour of full sun (assuming 80% of the 400 watt capability), which will require 8-9 hours of sun per day to replenish your daily use. If you think you're going somewhere where you'll have cloudy days, consider more battery capacity.
You should plan to have enough capacity from your solar and batteries to cover your use. That way whatever the alternator or inverter gives is just a bonus.
Note that solar isn't the only way to accomplish this but ultimately, your problem is that your storage tanks (batteries) are too small for what you're trying to do. That is why they had short life and I bet pitiful performance. Honestly I'm surprised they lasted as long as they did.
