Battery Parasite Draw or Normal

BFL13 wrote:

Got to be careful with this stuff in case we confuse a newbie.

Good stuff BFL.

Seems to be some confusion here. 12s unless true deep cycle like T-1275s have less antimony so they self discharge less than 6s with their higher antimony.

Self discharge is related also to how clean the battery tops are for any battery type.

It would be interesting to have some data whether there is more self-discharge for a pair of T-1275s in parallel than with a pair of 6s in series. I have both types but have no data on that.

12.3 is 60% with some wet batteries not 12.2 which is 50% with some (12.1 is 50% with others). Anyway the usual rule is to stay above 12.4 but then you have to consider which type of battery you have. AGMs have a higher resting voltage than wets eg.

Got to be careful with this stuff in case we confuse a newbie.

pianotuna wrote:
Hi,

It has nothing to do with voltage and everything to do with the chemistry of the battery. Most six volt batteries in use by RV folks have high antimony content and may self discharge at up to 1% per day.

A modest solar system would be a good way to keep the batteries in tip top shape between trips.

MNtundraRet wrote:
The self discharge rate mentioned is more for 12v batteries than 6v batteries.

The batteries should be recharged at least by the time they get to 12.2 volts (60%). It would be better to do it at least every other month during storage to keep sulfation from occurring on batteries below full charge.

Better yet, get a solar-panel of at least 10 watts to keep fully charged (12.6+v) battery(s). A larger panel would be needed to help recharge batteries with some discharge.

Batteries connected in parallel prey on each. The reason for a larger drop. Two 6-volts are connected in series so they do not prey on each other. Any other reasons for drop on disconnected batteries has more to do with the quality of different brands.

Of course for those of you with more than one pair of batteries: "ALL BETS ARE OFF!". :B

Twelve point five volts is too low to store a battery. Verify your meter is correct, then start out with the batteries fully charged in the 12.7 to 12.82 range. When the battery voltage droops to 12.4 it is time to top charge them if they have no maintenance charger on them, usually a month or so down the line depending on temperature.

Hi,

Yes, the newer the battery the less the self discharge.

Check which items are wired directly from batteries.....bypassing disconnect switch.

LP Detector
Smoke Detector
CO Detector
Slide outs.....although there should not be any draw
Radio/entertainment center (clock/memory??)

pianotuna wrote:
Hi,

It has nothing to do with voltage and everything to do with the chemistry of the battery. Most six volt batteries in use by RV folks have high antimony content and may self discharge at up to 1% per day.

A modest solar system would be a good way to keep the batteries in tip top shape between trips.

This but with new 6V's it's more likely 1% per week. 12V batteries would be around 2-3% per month.

Hi,

It has nothing to do with voltage and everything to do with the chemistry of the battery. Most six volt batteries in use by RV folks have high antimony content and may self discharge at up to 1% per day.

A modest solar system would be a good way to keep the batteries in tip top shape between trips.

MNtundraRet wrote:
The self discharge rate mentioned is more for 12v batteries than 6v batteries.

The batteries should be recharged at least by the time they get to 12.2 volts (60%). It would be better to do it at least every other month during storage to keep sulfation from occurring on batteries below full charge.

Better yet, get a solar-panel of at least 10 watts to keep fully charged (12.6+v) battery(s). A larger panel would be needed to help recharge batteries with some discharge.

Use a test light and see if the disconnect is really disconnecting, I suspect it isn't. Others have had similar issues, check the wiring.

The condition you see is normal but you have to do something about it. Batteries should be on "disconnect" to lessen discharge from phantom loads. The self discharge rate mentioned is more for 12v batteries than 6v batteries.

The batteries should be recharged at least by the time they get to 12.2 volts (60%). It would be better to do it at least every other month during storage to keep sulfation from occurring on batteries below full charge.

Better yet, get a solar-panel of at least 10 watts to keep fully charged (12.6+v) battery(s). A larger panel would be needed to help recharge batteries with some discharge.

When we owned a trailer I normally removed the batteries and stored and checked them at home.