Battery observations of winter storage.

[Gjac]

I winterized the MH in late Oct, pushed battery disconnect to store for house batteries and disconnected the neg cable on my chassis battery. Checked house batteries in Feb and they lost 20% SOC. Checked again today and they were only down 10%. Of course in Feb it was in the 20's and today we are up in the 60's. The batteries are still at 90% SOC after 5 plus months sitting with no charge on them. Each year I think this is it the batteries won't make it through the winter because the batteries are 14 years old but it looks like they will make it another year. I really like the 2 6v GC batteries from Sam's Club, I think back in 2007 they were made by Duracell.

[Gjac]

2oldman wrote:
I think disconnection is a very good storage method. I have a small car that I just disconnect the negative cable, and after 6 months of winter it starts right up.

Yes I have always done this for 14 years. One thing I don't hear talked about on here is when you keep your batteries plugged in 24/7 which many do there is some kind of chemistry taking place that must lead to some plate shedding. I only dry camp so the only time I hook up is to recharge the batteries after a week or so. Maybe someone can shed some light in this area.

[Gjac]

Lwiddis wrote:
A 30 watt solar panel and a $25 WindyNation weatherproof 4 stage controller will solve all your battery issues when in storage.

I think my post proves I have no battery issues while in storage.

[DrewE]

time2roll wrote:
The cold will dramatically slow the self discharge.

This is true. If memory serves, the rough rule of thumb was half (or double) the rate for every ten degrees Celsius down (or up) in temperature. A couple weeks in Florida summer weather will cause more self-discharge than all winter in a cold (sub-freezing) place.

[wa8yxm]

If possible I like the battery tender method of storage. however not always possible. The method the O/P used #2 on the list.

[Lwiddis]

“But each year I wonder the same thing. Last year batteries still lasted 7 days of dry camping before reaching 50% SOC”

Nothing magic about a 50% SOC. And each day a lead acid battery isn’t fully recharged shortens their life. An adequate solar system solves the issue.

[Monaramblee]

My 12 volt house battery is maintaining 12.8 volts for the last few weeks with the disconnect method.

[Lwiddis]

A 30 watt solar panel and a $25 WindyNation weatherproof 4 stage controller will solve all your battery issues when in storage.

[2oldman]

I think disconnection is a very good storage method. I have a small car that I just disconnect the negative cable, and after 6 months of winter it starts right up.

[Gjac]

I have a 1000 W MSW that I rarely use anymore. But each year I wonder the same thing. Last year batteries still lasted 7 days of dry camping before reaching 50% SOC, basically what I have seen over the last 14 years. I may have gotten a little more careful with battery usage over the years but not much.

[2oldman]

Gjac wrote:
the batteries are 14 years old but it looks like they will make it another year. I really like the 2 6v GC batteries from Sam's Club,

If you're running an inverter I wonder how much capacity they still have. I ran Trojan 6v with a 2k inverter, pretty heavy use, and could notice a definite degradation after 4 years.

[Gjac]

I use a multimeter to check SOC. Temperature is measured with a thermometer.

[full_mosey]

Gjac wrote:
I winterized the MH in late Oct, pushed battery disconnect to store for house batteries and disconnected the neg cable on my chassis battery. Checked house batteries in Feb and they lost 20% SOC. Checked again today and they were only down 10%. Of course in Feb it was in the 20's and today we are up in the 60's. The batteries are still at 90% SOC after 5 plus months sitting with no charge on them. Each year I think this is it the batteries won't make it through the winter because the batteries are 14 years old but it looks like they will make it another year. I really like the 2 6v GC batteries from Sam's Club, I think back in 2007 they were made by Duracell.

What kind of meter do you have that knows SOC based on temperature?

HTH;
John

[full_mosey]

MEXICOWANDERER wrote:
Duracell is a re-brand. Perhaps John Controls? A helping hand for warm weather use and storage is to adjust electrolyte density to 1.260


This must be done when the battery is brand new. It should be top charged and rested for a day. This can easily add 30 - 50% added lifespan.

In the Sams Clubs I have seen that the Duracells are Deka-East Penn and the Energizers are Johnson Controls.

HTH;
John

[time2roll]

The cold will dramatically slow the self discharge.