Community Forums

Telephonebil · 11-20-2024, 10:59 AM

I have 2 6volt for house. 12 volt for driving. whole system is 12V.
Batteries keep going dead while in storage. Looking at solar charger. i am thinking of just putting it in the front window while in storage.

1. can i use a solar charger in cig adapter to charge?
2. is it better to put directly to battery.
3. what brand? size 20w/30w?
4. Harbor frieght? amazon?
5. do i need two?
anything else to know, TIA.
Bill

Old Scout · 11-20-2024, 11:05 AM

Until you determine what is causing your bats to discharge--it difficult to determine how much solar you need to solve the issue. What actions are you taking to isolate/prepare your bats for storage, eg, disconnect the battery cables, or add a cable disconnect switch, leave plugged into shore power/trickle charger?

Mark_K5LXP · 11-20-2024, 01:15 PM

Disconnecting doesn't cost anything and is 100% effective. You don't know your load nor your solar potential (angle, shading, windshield losses). Even if you bothered measuring all that, you end up buying something and having to deploy it just to break even. Disconnecting a cable obviates all the costs and issues of relying on solar.

Mark B.
Albuquerque, NM

Arch Hoagland · 11-20-2024, 01:24 PM

https://www.amazon.com/Battery-Disco...zcF9hdGY&psc=1

This will solve your problem.

Soppy · 11-20-2024, 03:39 PM

Don't bother with a solar charger. Just fully charge your batteries, then disconnect them. They will easily last 6 months in storage in any kind of weather. Best of all , it doesn't cost a cent and will never fail.

Persistent · 11-21-2024, 10:22 AM

Good advice posted above.

Without disconnecting the house battery bank, you should get 1 to 3 weeks of satisfactory storage. Fully recharge for 10 hours before battery voltage drops below 12.4 volts.

Fully charge for 14 to 18 hours before storage. This removes all lead sulfate from the batteries.
Disconnect.
Fully recharge for 10 hours before battery terminal voltage drops below 12.4 volts. This keeps lead sulfate from building up on the plates.

Lead sulfate is normal in lead acid batteries. However, it has the annoying behavior of crystalizing slowly. Keeping the lead sulfate off the plates provides long useful life for the batteries.

That said, you have a serious problem if your vehicle starting battery is going dead in a couple of weeks. You should get a month or so.

You need to find the source of the power drain and eliminate it. Nothing good can come from ignoring the issue.

Persistent · 11-21-2024, 10:30 AM

I have 2 6volt for house. 12 volt for driving. whole system is 12V.
Batteries keep going dead while in storage. Looking at solar charger. i am thinking of just putting it in the front window while in storage.

1. can i use a solar charger in cig adapter to charge?

No. Most cigarette lighters are disconnected when ignition is "OFF".

2. is it better to put directly to battery.

Panel to solar controller.
Solar controller directly to battery.

3. what brand? size 20w/30w?

Solar panels are cheap these days. Might as well get a standard 100 watt panel. 30 watts may maintain some systems. It may not be enough for others. Until you know how much parasitic draw you have you will not know.

4. Harbor frieght? amazon?

Yes. Also Home Depot, Menards, any home/building store. Dozens of websites.

5. do i need two?

Total capacity matters, not how many.

You may need one for each battery bank. The two banks may not be connected when ignition is "OFF".