Keeping batteries charged

[rbs]

Our very recently purchased 2004 Airstream came with Optima batteries. I don't have the receipts in front of me, but I am thinking they are 3 years old. I know that the original owners kept the unit plugged it to 110 while in use and during storage. I have been reading and learned this is probably a death sentence for the batteries as the converter/battery charger is the original 7455 Parallax unit. Is there anyway that I would be able to check the batteries to determine if they are toast? I am getting everything setup for winter storage, wanted to remove the batteries and purchase the correct charger to maintain them. From my readings so far looks like a Battery Minder would work just fine. I also will be changing out the converter in the near future.
Thanks in advance,
Rod & Jane

[ROBERT CROSS]

Rod,

Do you have a charger that will safely charge the Optima's?, blue top?

If so, charge fully and have them tested at a local NAPA or battery retailer,(Interstate).

There are better choices for the AS if they are bad.

Have had good luck with Interstate grp27 Marine/RV Deep Cycle.
Changed to AGM Lifeline's three seasons ago when I installed the Iota 55a DLS IQ4.

Bob

[Phoenix]

If the Optimas test OK, they are supposed to hold a charge for 6-12 months. We charge ours overnight, once a month; but they went 3-4 months while in storage one time without recharging, and were still OK when we took our Bambi out.

The biggest thing is to disconnect them completely from your Airstream during storage, as parasitic loads will drain them in only a week or two. The easiest way to do this is with a marine battery isolator switch. See posts below.

Note: Second post is for photo and description only. I don't know if this is the best price.

http://www.airforums.com/forums/f449...tml#post662384

http://compare.ebay.com/like/4002579...Types&var=sbar

[Jack46]

I agree with others here that a battery cutoff switch helps. I too have Optima Blue Tops and generally we'll leave the trailer unused for about four months. A cutoff mounted at the batteries eliminates any drain and we've always been fine when getting cranked up again in March. I also use a small solar charger mounted on top of the propane cover. I'm not sure how much that has helped, but all I need is to be able to easily get the trailer hooked up to get us to the nearest power source - usually to the house to get her ready for the new season. Good luck.

[Gene]

Rod, the simple way to check batteries is to use a hydrometer—they are cheap and easy to find in auto parts stores. For most purposes they work fine although there are more accurate ways to do this. If you want to check the battery voltage any voltmeter or multimeter will do so. Fully charged they should be between 13 and 14 volts DC.

There are some electronic items in the trailer that will pull small amounts of electrons, but it mounts up after a while. If you have a subwoofer, it is on all the time unless someone installed a switch (as I have). The propane detector is always on and some other items may also draw phantom loads. The mysterious battery disconnect switch appears to leave the propane detector connected.

You check each cell with the hydrometer and see if they are ok and if any are dead. Make sure not to get the battery water on your clothes unless you like holes in them—even a drop can do that and I can prove it.

Until you change the converter, just plug the trailer into shore power every month or so overnight and check voltage in the morning with shore power unplugged. They can test good with a hydrometer, but be old and tired and not hold a charge very long. It is a good idea to check after several days or weeks to see if they are holding a charge.

We changed to an Iota converter and Lifeline AGM batteries (like Bob Cross) last summer. The Iota has a multistage charger. Before that we used the solar panel to keep the batteries charged and the trailer unplugged—the solar charger was multistage. And before that, the first winter, we left the trailer plugged in. I didn't realize Airstream wouldn't spend a few more dollars to include the multistage charger option with the converter. The batteries kept charged, actually overcharged, and I had to add water a few times over the winter. Once we unplugged and let the solar unit charge them I hardly ever had to add water.

Jack's solution—using a small solar panel can help if it has enough wattage, but if it doesn't have a multistage charger, you are in no different a place than using the OEM converter.

Wet cell unsealed batteries seem to last 3 to 5 years depending on how they were cared for, quality, and luck. If you upgrade to Series 27 or higher or golf cart batteries, you will have to modify the battery box—measure carefully. High quality AGM's cost a lot more, but last a lot longer, so they seem to be about equal. You have less worry and don't have to change them as often.

Gene

[AirHog]

I pulled the batteries out and have trickle chargers attached to them. They are showing 13.5volts. Are they over charged?. I will draw them down to 12.4V or so and recharge them. Comments/opinions will be helpful.

Many thanks.

Titu

[rbs]

I pulled the batteries and called Optima to find out the correct procedure for charging. The batteries were purchased 6/06, and Optima told me that would be probably close to life expectancy. Anyway, I charged one battery, using my charger set at "Deep Cycle" at a 2 amp rate. Checked the volts after it showed fully charged and the meter showed 13.05 volts. I am charging the second battery now, and will maintain them with a Battery Minder. I am going to start my research on solar chargers, looks like Lifeline batteries are the best bet for boondocking, and changing the converter/charger will pay benefits in battery life. The sealed tops of the Optima battery will not allow me to test with the hydrometer, although that is what I used for testing my trolling motor batteries. So much to learn, but all of the answers are right here, thanks so much.

Rod & Jane

[ROBERT CROSS]

Originally Posted by AirHog

I pulled the batteries out and have trickle chargers attached to them. They are showing 13.5volts. Are they over charged?. I will draw them down to 12.4V or so and recharge them. Comments/opinions will be helpful.

Many thanks.

Titu

Titu,

I would let them sit 24hrs and re-test. 12.6v is considered a full charge.

Bob

[Mike91208]

Originally Posted by reshecca

I'm also looking for ways to maintain my batteries between trips and am in the process of learning about BatteryMinders. I have 2 batteries in my 2010 Flying Cloud ~ do I need a battery minder for each battery? Or can I charge/maintain both simultaneously? Or one at a time...?


BatteryMINDer Charger/Maintainer/Desulfator — 1.3 Amp, 12 Volt, Model# 12117 | Battery Maintainers | Northern Tool + Equipment

I have the single BatteryMinder solar panel 15w and, yes, it works GREAT for maintaining both batteries between trips. Just make sure you hook the positive wire to one battery and the negative wire to the other battery.