Charge Batteries by Idling Tow Vehicle?

Look into solar panels and an adjustable voltage charge controller set to 14.8V for most lead acid batteries, for recharging your batteries also. Some lead acid batteries may require up to a full 15.3 volts daily to fully recharge. Read the battery manufacturers specs to find out for certain, on their website, or call and speak to an engineer.

Do a search.

Seems like almost every RV park there is always a few hold outs who just refuse to spend a couple of dollars for a diode and 10 ft of wire for a charge line. Hoods up with battery chargers. Never heard this one before. Leave your toad running while towing or run it all night in the RV park. I guess it's not money it is principle. Actually it did cost me almost $5 for the wire, diode and small box to put it in.

Nothing like running an 8 cylinder gas engine for 3 hours to charge batteries. The exhaust would be wonderful too.

You will have to use a multimeter across your RV battery terminals and see if it is showing 13.2VDC to 14.4VDC when the truck motor is at idle speed.

The rules for charging batteries is at play here...

This is what PROGRESSIVE Dynamics states in their operating manual on how long it takes to charge a battery using the DC VOLTAGEs listed below:

"Progressive Dynamics ran this test on the amount of time it took a PD9155 (55-amp) converter/charger set to three different output voltages to recharge a 125 AH (Amp Hour) battery after it was fully discharged to 10.5-volts.

14.4-VOLTS (Boost Mode) – Returned the battery to 90% of full charge in approximately 3-hours. The battery reached full charge in approximately 11 hours.

13.6-VOLTS (Normal Mode) – Required 40-hours to return the battery to 90% of full charge and 78-hours to reach full charge.

13.2-VOLTS (Storage Mode) – Required 60-hours to return the battery to 90% of full charge and 100-hours to reach full charge."

This is based on having 17-20AMPS DC current available for each battery in your battery bank... NOTE That Progressive Dynamics doesn't even list using DC Charge Voltages around the 12.0VC range as this would take alot more than 100 hours to achieve a 90% or 100% charge state.

This will be running your truck for a long time period... Minimum charge time would be three hours to achieve a 90% charge state using 14.4VDC BOOST charge.

If you are thinking to just charge your battery for short times you may end up doing damage to your batteries... For them to produce almost full performance they have to start out with at least a 90% charge state...

This is what we have experienced at any rate camping alot off the power grid...

Roy Ken

romore wrote:
Al you will do is waste fuel and annoy the neighbors, you would need to run at a high idle for an extended period of time to recharge depleted house batteries. Plug into shore power or use a QUIETgenerator.

So called Quiet generators annoy the neighbors as much as a truck running. where we dry camp. You can hear a "quiet" generator running 100 yard away.

To the op. you can charge the batt with the TV. But it will take awhile

Al you will do is waste fuel and annoy the neighbors, you would need to run at a high idle for an extended period of time to recharge depleted house batteries. Plug into shore power or use a QUIETgenerator.

Because it can take hours to charge batteries.