advisability to turn off battery periodically

My opinion is to charge up, then disconnect for about a month and check them. And I don't mean the battery 'disconnect', I mean remove a cable.

I leave a car in the winter for 6 months with a disconnected battery and it starts right up.

You should be able to adjust the absorption mode voltage downward. With my old charger that was not possible and my batteries lasted 7 years when left hooked up at a constant 13.6 volts.

WFCO should actually be going into "storage" or "float" mode when no load draw has been present for a predefined period of time. Storage or float voltage is roughly 13.2V, not absorbtion which is higher than storage.

See HERE for WFCO stage voltages.

See page 7 HERE for more explanation..

A "bad" battery most likely will force the WFCO in staying in absorbsion mode especially in the case of a bad cell.

These converters measure voltage and current to determine what mode to go to and use a timer for each mode.

For detailed explanation you can go to WFCO Theory of Operation document HERE Page 2.

I quote "Float Mode-is third stage of converter operation. This mode is to provide a trickle charge to the battery. If converter observes no significant variations in current draw for approximately 44 continuous hours, it will drop the output of the converter from 13.6V to 13.2V..

..This lower voltage will keep the battery charged while the RV is not in use..

..A change in DC current will cause the converter to exit Float mode and return to default, or normal, Absorbtion Mode."


If you have things turned on like a fridge that may even be enough to wake up the converter and stay in absorbtion mode.. Turn everything off and wait 44 hrs and see if converter changes to storage.

Or as others have noted, too long or too light of wiring between converter and battery allows too much voltage drop which can cause WFCO converters to sort of hang up on switching stages. The fix to that is to replace existing wire from converter to battery with a heavier ga wire which reduces the voltage drop between them.

If you disconnect the battery, you will need to periodically remember to connect it and allow the battery to recharge for a day or so. That replenishes the "self discharge" that happens naturally with batteries.

Otherwise if you can determine and fix what is keeping the converter from going into storage you can just leave everything connected and the converter powered up 24/7.

Timeking wrote:
Had a cell die, and then the WFCO burned it to a crisp. Had to replace battery and the acid-laden case.

It seems there is little advantage (?) in keeping the battery charging ALL the time when connected to shore power. A fully charged battery measures 12.9 volts, yet the WFCO in 'absorption mode' is hitting the battery with 13.6 volts, as it was designed to do. Doesn't seem healthy to be continually running current through the battery, month after month after month, which I suspect can only increase gassing, and loss of water ... and bad cell and kablooey.

What might I be missing here?

When I turn the battery OFF, it does not get charging current.

The battery was shot and the issue was probably not the fault of the WFCO.

Either way the battery was bad. The WFCO did not kill it, turning the battery off would not save it.

Although the WFCO is notorious for not changing modes as expected. Might do better with replacing the converter.

Assuming you have the 8900 series I recommend the Boondocker MBA 45 amp

Thanks. I am full-time living in the TT, and still wonder why when connected to shore power 100% of time, that it is good and/or I need to keep charging the battery. Since I am constantly using light, pump, etc., the WFCO will never go into storage mode, but will always stay in absorption mode.

My question is whether it is good for the battery to get hit with 13.6volts for endless months, or whether it is best to disconnect the battery as long as the battery is still well-charged.

Won't "hurt" the battery, but will boil the electrolyte so you will need to constantly check and refill the water level. 13.6V will boil off water and if you fail to replenish it will boil the battery dry which is most likely what happened to your last battery.

If you are permanently setup and have zero intentions of ever moving the trailer you might consider just skipping a battery altogether as it is not needed in order for the WFCO converter to work. In this case the battery is more of a hassle and cost that isn't needed.

Modern converters do not need a battery to regulate and maintain 12V.

You will however be subject to having all 12V devices stop working whenever you have a commercial power outage, sort of like a sticks and bricks home..

If you might wish to move the trailer, of course you would need a battery to operate the emergency break away system..

You can of course disconnect the battery, but then you must remember to reconnect once every 3 to 6 months and allow the battery to fully recharge for a day.. Good chance you will eventually forget.

If you already have bought a replacement, you could see if they would take it back and get your money back if you do not plan to move it anytime soon..

I would get a one week timer. I'd set it to charge the battery bank 1 hour per week for each 100 amp-hours of storage. The Boondocker MBA 45 amp is an excellent choice.

pianotuna wrote:
I would get a one week timer. I'd set it to charge the battery bank 1 hour per week for each 100 amp-hours of storage. The Boondocker MBA 45 amp is an excellent choice.

Thought about mentioning a timer, but since OP isn't moving the RV, why bother with a battery in the first place? Which is why I didn't mention a timer.

Since OP is constantly using the RV, they are not "storing" the RV a timer would most likely end up severely under charging since one would be making a bunch of haphazard guesses as to how long to turn on and off the charger..

In this case, no battery at all just makes the most sense since they are not moving the RV.. It is simply not needed and having one there to tends to be a waste of money if it isn't being used or needed.

Yes you can turn off the battery. If you don't move you don't even need a battery. Charging the otherwise unused battery every 1 to 3 months overnight is fine.

Yes the function of the WFCO is very poor. The linked converter should go to 13.2 volts after a few days.

time2roll wrote:
Yes you can turn off the battery. If you don't move you don't even need a battery. Charging the otherwise unused battery every 1 to 3 months overnight is fine.

Yes the function of the WFCO is very poor. The linked converter should go to 13.2 volts after a few days.

Timeking wrote:
Thanks. I am full-time living in the TT, and still wonder why when connected to shore power 100% of time, that it is good and/or I need to keep charging the battery. Since I am constantly using light, pump, etc., the WFCO will never go into storage mode, but will always stay in absorption mode.

OP is fulltimer and will be "using" battery all the time and that is the problem, so pretty much negates any multistage converter from ever going into storage mode of 13.2V.

Typically multistage converters will have a specific amount of time after the last usage of current before it drops into storage.. OPs constant use of 12V items will prevent multi stage converters from seeing a lack of use long enough.. WFCO uses 44hrs of inactivity before dropping to storage.

Nothing "weak" about that for a WFCO and even the one listed above will have the same issue.

Op doesn't really need a battery at all if they are staying put and if that is the case the simple answer is to lose the battery.