Generator vs Battery/Inverter/Solar
We have just purchased our first truck camper - a used 2007 Lance 845 and have a couple questions that I hope you can help us out with. The camper is still at the dealer and we're considering having a...
Forum Discussion
You are misreading my post and misunderstanding a bit of what is going on.
All of this discussion assumes that you are using roughly similar batteries, specifically lead acid and not lithium iron.
-- You DO want shore/solar power to reach your starter battery. If you use an intelligent relay (aka, voltage sensing relay, automatic charge relay, etc.) this will happen automatically and you will not have to use an additional product like the AMP-L-START or similar. While my truck actually uses a Magnum Energy "Smart Battery Combiner" driving a Blue Sea relay, I rather prefer the Blue Sea ACR.
-- GM alternator/regulators are very sophisticated, even going to full alternator shutdown as a fuel saving measure under certain circumstances. This is very, very rare, however when you combine air conditioning and the various loads of a camper. Under those circumstances you almost always have so much drain that the voltage will never drop to a classic float voltage.
In my case, the refrigerator, and often the heater, are enough to assure a background drain of as much as 5A, peaking to 15A. Thus I want the voltage to stay around 14v whenever the engine is running. The AMPERAGE, however, will drop and thus there is no danger of the starter or the camper battery overcharging. I do have the charge voltage on the solar controller capped at 14.9v as my heater will fault if it sees 15v.
My solar controller will drop to a true float, but only when I have all of the loads (e.g. heat, fans, refrigerator, composting toilet, etc.) shut off and the engine shut down.
So basically you need a higher voltage to assure a full charge. That voltage will not harm your batteries unless the amperage is too high.
Two years in, running massive loads, and without a genset, my batteries still perform like new.
As always, YMMV.
All of this discussion assumes that you are using roughly similar batteries, specifically lead acid and not lithium iron.
-- You DO want shore/solar power to reach your starter battery. If you use an intelligent relay (aka, voltage sensing relay, automatic charge relay, etc.) this will happen automatically and you will not have to use an additional product like the AMP-L-START or similar. While my truck actually uses a Magnum Energy "Smart Battery Combiner" driving a Blue Sea relay, I rather prefer the Blue Sea ACR.
-- GM alternator/regulators are very sophisticated, even going to full alternator shutdown as a fuel saving measure under certain circumstances. This is very, very rare, however when you combine air conditioning and the various loads of a camper. Under those circumstances you almost always have so much drain that the voltage will never drop to a classic float voltage.
In my case, the refrigerator, and often the heater, are enough to assure a background drain of as much as 5A, peaking to 15A. Thus I want the voltage to stay around 14v whenever the engine is running. The AMPERAGE, however, will drop and thus there is no danger of the starter or the camper battery overcharging. I do have the charge voltage on the solar controller capped at 14.9v as my heater will fault if it sees 15v.
My solar controller will drop to a true float, but only when I have all of the loads (e.g. heat, fans, refrigerator, composting toilet, etc.) shut off and the engine shut down.
So basically you need a higher voltage to assure a full charge. That voltage will not harm your batteries unless the amperage is too high.
Two years in, running massive loads, and without a genset, my batteries still perform like new.
As always, YMMV.
