Running the generator while driving to charge house batteries - RV-Dreams Community Forum

mjlitz · RV-Dreams Family Member

Running the generator while driving to charge house batteries

TRAILERKING · RV-Dreams Family Member

All my batteries charge from the alternator while driving. Nothing wrong with running the generator while touring down the highway if you wish.

Sushidog · RV-Dreams Family Member

Do you have a trailer or self contained RV?

Chip

mjlitz · RV-Dreams Family Member

New class A DP
Thanks for the info

bjoyce · RV-Dreams Family Member

The alternator will not handle the last bit of charging, so don't expect it to do a full charge. The voltages are not high enough. Some towable people add more charging wire between their truck and trailer to get a better charge, which should be a cheaper solution than a lot of generator fuel. But in all cases, don't run your alternator over about 1/2 for more than 15 to 30 minutes, it is not built for it.

Barbaraok · RV-Dreams Family Member

Bill,

I believe they have a DP like we (and you) do. I know our house batteries charge while we are traveling, I assumed that all of us with MHs had that happen. Maybe not?

Barb

Lonney Wade · RV-Dreams Family Member

My truck has 2 alternators on the Diesel engine.
I have run a heavy 2/0 cable from the trucks battery compartment all the way to the 5fter and can run the roof air conditioning and the fridge going down the road and fully charge the RVs batteries very fast 100%
The AGM batteries can be charged very hard and fast. I have learned how to charge the batteries 100% in no time, I'm talking very fast and the batteries are 3 years old and still taking it. I have put a meter on the battery cable at 284 amps going in the batteries. I will be doing a Youtube video on this soon, I've had a lot of people inquire about this, I've also talked to a guy at Johnson Controls with the technical department who build the batteries for the electric cars, he want's me to come down to talk to his guys, so wish me Luck !!!!!

Lonney

-- Edited by Lonney Wade on Tuesday 29th of July 2014 01:25:03 AM

-- Edited by Lonney Wade on Tuesday 29th of July 2014 10:07:07 AM

BiggarView · RV-Dreams Family Member

Lonney Wade wrote:
...The AGM batteries can be charged very hard and fast. I have learned how to charge the batteries 100% in no time, I'm talking very fast and the batteries are 3 years old and still taking it. I have meter the battery cable at 284 amps going in the batteries. I will be doing a Youtube video on this soon...

Looking forward to seeing it... sounds very interesting

Brian

folivier · RV-Dreams Family Member

I've done just that when the alternator belt broke until I could replace it. But you should get it sorted out, your alternator should have a relay that allows both sets of batteries to be charged while driving.

lindy · RV-Dreams Family Member

If you mean NEW DP as in made in the last 6-8 years your Alternator should keep hour house batteries charged. If they are not being charged at all, then get it looked into while still under warranty.

bjoyce · RV-Dreams Family Member

Barb: I didn't say the alternator didn't charge the batteries, only that it did not do the full charge that deep cycle batteries need. Both of the motorhomes we have had alternators that put out a maximum of 13.7/13.8 volts. Deep cycle batteries need voltages around 14.4 to 14.8 to fully charge. That is OK if you have a good converter with a 3-stage charger or an inverter/charger, and plug in or use your generator at least once a week to get that last bit of charging. Starting batteries are not so picky, which is what the alternator is designed to charge.

I don't think any of us is in the 8 or more battery world and using a stock alternator. But if you are and boondock hard, you can't expect the alternator to do the bulk charging of your battery bank. People have burned out their alternator with big battery banks. After a large battery drain, they need to run their generator to do the bulk charging and not expect the alternator to do it all.

A stock DP alternator is around 170 amps in size and designed to run at 50% or less load for extended periods, or around 85 amps. A big battery bank can bulk charge at the maximum load of the alternator for a couple hours if the batteries are drained.