Keeping Batteries Charged While in Storage

[beachbouy]

Looking for sugestions on temporary and removable solar method to keep batteries charged while AS is stored as they slowly drain over six weeks when not in use. Rather secure storage.

Two Interstate SRM-24's - cranking amps 690 and cold crank is 550.

I know I need a solar controller along with a panel... BUT will not be boondocking... no need to go overboard.

[switz]

A small battery trickle charger if you access to 120Vac is one choice, the other is to disconnect the positive cables on the batteries or install a disconnect switch to completely isolate both sets of batteries.

[lewster]

This: http://www.northerntool.com/shop/too...8565_200328565 will make a nice solar trickle charger. I have installed several on larger cargo trailers and it does an acceptable job of keeping their batteries topped off.

Everything you need is included too.

Should work especially well in FL with all of the winter sunshine……….

[lewster]

Or…..try THIS: http://www.amazon.com/BatteryMINDer-...battery+minder

[Siegmann]

Originally Posted by beachbouy

....while AS is stored as they slowly drain over six weeks when not in use....

If you only store it for a few months, you can just put a switch on your propane detector (and any other phantom loads that are connected directly to the battery).

With no current draws, they'll be fine.

[alano]

A marine quality 300 A battery switch mounted to your battery box would be a convenient method to disconnect and reconnect the battery while in storage. This would remove all your parasitic loads.

[biyak269]

When the time comes, install AGM batteries. They can still operate the tongue jack after sitting for, in my experience, up to 6 months over Michigan winters. The LP monitor doesn't seem to discharge them appreciably. For the belt and braces approach, you can disconnect the positive terminal or add a switch.

Bonus: I've had AGMs last 8 years before needing replacement in watercraft.

I use them in trailer and tow vehicle, and have had good results with several brands.

[greenflag]

I bought a similar product at Camping World a few years ago.
A trickle charger often does not require a controller. It worked well.
You can also disconnect the negative cable.

http://www.campingworld.com/shopping...s-6-watt/56005

[nickmeloy]

Originally Posted by lewster

Or…..try THIS: http://www.amazon.com/BatteryMINDer-...battery+minder

I have one of these units. It keeps the two group 27 batteries charged for unlimited time periods.
The manufacture claims that this system will also prevent the batteries from becoming sulphated. I have no idea if this claim is valid (perhaps Lewester will comment on this claim).
If you have covered storage, then the solar panel must be external to the cover, and the electrical lead is not very long.

[r carl]

I just disconnect 1 battery cable.

[tjdonahoe]

Originally Posted by r carl

I just disconnect 1 battery cable.

That's right, and it is cheap insurance, and it doesn't cost anything and the batteries will last 4-6 months.....

[CruizinDux]

I originally looked at solar trickle panel (HD/Amazon by Coleman) and understood that 5 watts or less didn't need a controller. I was also motivated somewhat in that I I had a new unit with dealer neglected batteries & unable to hold a charge (some that that IMO). I abandoned the solar idea as I thought it may conflict with a possible conversion from Interstate 2 srm 24 (12v) to Interstate GC2’s (6V) which if I have it correct necessitates a wiring change from parallel to series.

This is a thread that I saved. There are many others with much experience than I can offer.

http://www.airforums.com/forums/f449...-124829-2.html

After reading the threads, I realized that the radio as well as the propane detector was a draw. Now I disconnect the curbside negative connection as my storage has no AC to support trickle charge. If it's longer than 60 or so days between use, I bring them home and hook them up to a smart charger and call it good.

When the 24's are gone, I'll convert to the 2 6v golf cart batteries and raise the box lid as IDROBA did in the above link to accommodate the greater height. At that time I'll wire a remote isolation switch.

Bob

[GailMac]

I also use a small battery trickle charger & it works great if you have 120vac. Got mine at the Academy.

[Zstreamer]

I use a 10w solar Battery Tender I bought from Amazon for around $70. I put right on top of the propane tank unit and tie down with bungee cord. It gets sun for about 5 hours a day before its in the shadows / darkness. Keeps both my batteries fully charged all the time. In the am, the batteries drop to about 12.5 V or 90% charge. By mid day, they are back to full charge at around 12.7. My AS came with a detachable Clarion head unit so I simply detach it and that eliminates the parasitic draw to the audio. Propane stays on but the 10w tender handles that no problem

[Zstreamer]

I meant to say propane detector stays on not the propane itself

[SeaLevel]

Originally Posted by Zstreamer

I meant to say propane detector stays on not the propane itself

I thought that was what you meant. Thanks for the tip on how you mount yours. I just got the 15W unit mentioned earlier, and was planning to do something similar, so its good to know it works. I should get some good sun here in South Florida.

[dznf0g]

15 watts wasn't enough up here during the 8 weeks surrounding winter solstice. Too many gray days and too much sun angle. It was fine in the summer with relocating the propane detector downstream from the store switch. 15 watts will realistically give you about 750 - 900mA of charging in full sun for about 5 hours a day. I had about 150mA parasitic draw 24 hours a day.

[CruizinDux]

Originally Posted by Zstreamer

.... My AS came with a detachable Clarion head unit so I simply detach it and that eliminates the parasitic draw to the audio.

Zstreamer, what great tip, thanks. We just returned from our 3 week maiden voyage and was often re-reading the manual and do remember the reference to the (Sony) face plate. I just never made the connection...or rather disconnection.

Bob

[switz]

Another parasite power draw is the "instant on" feature of the televisions. We switched the television outlets for ones with a built in switch for the included outlet. Power off is power off completely. Turn it on when wanting to watch or when on shore power.

Using "LED on when on" power switches for the Voyager rear view camera, the always on sub-woofer and the audio system help with the parasite power loads. Another sneaky power draw when on inverter power is the microwave with it's clock.

We reused the original water heater power switch for the 12Vdc going to the Truma instant on water heater. We leave both the 12Vdc and the propane on when the temperatures are forecast for freezing temperatures and the Truma will keep itself from freezing. In warmer temperatures, both the propane and the 12Vdc are off.

[GatorDave]

I have used the Solar Battery minder that lewster recommended for several years. Keeps batteries topped off very well. Before I started using it the batteries would drain even when the disconnect switch was off. Am using Napa RV/Marine batteries. Was informed it is best to keep batteries fully charged to increase their life span. They would'nt last a year before I began using the battery minder. they are 3 years old and still function. When dry camping i use it to help keep a charge in the batteries. Have gone a week with no problem.