Battery charging and maintaining ?

Fleet Man wrote:
By the way, I also replaced my OE Parallax 7455T Charger/Converter with a PD 9260 unit which uses three automated charge rates.

And THAT probably did more to reduce your liquid loss than the mineral oil did.

Mineral oil will slow down or prevent real evaporation loss.....but most of the liquid that disappears is NOT from evaporation.
It is from electrolysis during charging (at too high a rate) that produces hydrogen and oxygen gas.......which the mineral oil does NOTING to stop.

Thanks everyone !

Unless things have changed, Winnebago began installing the Trik-L-Start on coaches with the 2007 models to insure both sets of batteries charged while plugged into shore power. Check your coach and your literature, you may be wasteing a worry.

I did the mineral oil trick on my lead acid house batteries and eliminated the problem of cooking the batteries and related corrosion. By the way, I also replaced my OE Parallax 7455T Charger/Converter with a PD 9260 unit which uses three automated charge rates.

time2roll wrote:


13.2+ is charging fine. 12.6 or less is not charging.

Can't tell much from just one reading.

13.2 is floating. If it never goes above that, then that won't be charging much or at all either.

Read batteries before plugging in and several hours after shutting engine off. 12.x
Less than 12 and you already have a problem.

Plug in shore power. Each set of battries likely will read around 14.5 after a few minutes. That is charging.

After 48 hours or so, both sets likely will read around 13.2. That is maintenance float voltage and if both sets do this, then you have no problem. Leave everything on and don't worry.....except checking the electrolyte level in the batteries occasionally....if they have removable caps.

If one set does not follow this pattern, that set needs a tender.

However, on my two units....a Ford C and a GM A, the chassis battery was fine for 3 months doing nothing to it. The house batteries were too by operating the disconnect switch.

Plug it in and check the chassis battery voltage after 48 hours. Check right on the battery terminals. Post the results.

13.2+ is charging fine. 12.6 or less is not charging.

donn0128 wrote:
Go buy a battery tender for the chassis battery. Leave the switch on. Plug in. Check battery water level monthly and your good to go.

With some models, ALL batteries are being charged and/or floated when on shore power. A quick voltmeter check on each set while shore power is active should tell you what that situation is.

And if you have a good converter/charger that really does drop to float after the batteries have a full change, then you just plug in and don't worry about it.

If you happen to have AGM batteries, there is no "water" to check either.

^^^^^^^^^^^ Love the battery tender

Go buy a battery tender for the chassis battery. Leave the switch on. Plug in. Check battery water level monthly and your good to go.

I have a 2010 Suncruiser and have found that to maximize battery life, turning off both is best. Keep in mind that you must make sure all 12 volt systems are off or you will drain the batteries. Dont forget your TV antenna booster or AV control box. Switch your radio over to the chassis battery.
I generally check the voltage of each battery once every few weeks and turn on the disconnect switch to recharge as needed. I have found that my batteries are generally fine for quite some time.