Trailer Battery Charger - Overcharging?

libtech01 wrote:
. but I read that it can have detrimental effects to battery life?

IF you believed everything that you read on the Internet you wouldn't be able to sleep at night. :E

EVERY RV OWNER NEEDS A MULTI-METER TO CHECK VOLTAGES. (At least one).

About 6 months ago, I caught an alternator failure early with the little monitor I keep plugged in all the time.

HIGHLY unlikely that the tow vehicles charging system would OVER charge the trailer batteries.....IF it is working right.

You can tell by checking the voltages and monitoring the water levels.

Very unlikely. Modern tow vehicles keep the voltage rather low in a misguided effort to save fuel. Also, the voltage drop in the long, too small charge line to the trailer will further reduce the charge voltage. I really don't see a tow vehicle coming close to overcharging anything with a stock set up.

I agree. It is more likely that you will damage those new batteries by never fully charging them.

You also need your batteries connected to provide power to your brakes in the event of a disconnect.

hedge wrote:
You also need your batteries connected to provide power to your brakes in the event of a disconnect.

I think the OP means his 7-pin connection, not about having a connected battery in the trailer.

Hot seat long-haul big rigs use lower alternator voltage regulator settings to minimize battery water loss.

Some tractors see their longest shut-down time to do a maintenance turn-around - chassis lube, oil change and wash job. Otherwise one driving team slides down and another climbs up. This is pretty much the most severe over the road alternator charging usage in the book. Even then, regulators are set for 13.8 volts. Short haul trucks like port container shuttling have voltage set to 14.0 - 14.1

This should give you some solid perspective about "the extremes".

The uneducated magazine keyboard tappers who create reality in exchange for a paycheck can be pathetic. There is a lot of hype these days over "Fake News". For certain, Fake News is not limited to "politics".

If there is anything to be said concerning unhooking from a power pedestal then driving 6 hours, it is most likely correct to say any added ampere hours would be doing an RV battery bank a favor. This can easily be verified with a hydrometer.

CAVEAT: ultra hot weather in excess of a hundred degrees F would negate any benefit from any addition of ampere hours. But many new ECU controlled alternator voltage regulators are more-or-less temperature compensated.

On a boiling hot day during a long drive, ponder the ramifications on your under hood engine starting battery. That is the "poor slob" in the battery group.

Consider also a battery monitor that displays the per cent of full charge as well as the voltage and current. The one I use was $25 on eBay and works very well. You could see what the alternator is doing to the batteries if and when they reach the fully charged state.

One of the low cost battery monitor threads:
https://forums.goodsamclub.com/index.cfm/fuseaction/thread/tid/28797618.cfm

No issues while towing. None.