AGM & Regular Lead Acid Batteries

[Smurffy]

This is a little confusing, so please bear with me. My husband asked me a question about these batteries that I was a little too quick to answer, so now I'm curious. I know you are not supposed to mix AGMs & flooded's together but...
We are running regular deep cycle lead acid batteries in our F350 Diesel. We want to put AGMs in our 5th wheel. This is the question:
While driving, the pickup is charging it's batteries and through the 5th wheel plug in, it's charging the AGM battery in the 5th wheel. Does this cause a problem? Is it the same as mixing the two types of batteries?

 

[Gronk]

More than likely your charge wire from the truck to the trailer is small enough that yes, it does charge the batteries, but no it won't supply enough to properly charge them. What I mean is there is such a distance from the batteries in the truck to the batteries in the trailer that you only trickle charge the trailer batteries mainly due to line loss (wire capacity and length). What I am trying to say is you should have no issue with putting AGMs in your trailer. IF you upgrade the charge wire to say #10 or larger you may be able to charge them better. I had a truck that had AGMs (of unknown age) in it when I bought it and when they failed (six years later) I put lead acid back in with no issues. In fact, I bought the truck in 2001 ('96 model) with AGMs, changed them in 2007, and far as I know the truck is still on the lead acids I put in. Son in law now owns the truck.........

 

[Kevin D Pem]

I''m pretty much with Gronk on this. Your AGMs have the voltage requirements on the battery. You will likely find bulk charge is 14.8 or close to it. Your truck voltage is 14.4. The float charge for your AGM is likely 13.8. More than likely your batteries will be getting 14.0 volts charging voltage. This translates into many hours for a complete charge.

Take the time to check the voltage out at the AGM posts and compare the voltage you should have for float charging and I think you will already meet that voltage. A rather large diode in the charging line will drop the voltage .5 volts if you need to go that way.