Battery/charger issues

[campercan]

I am new to trailer life, a jump from backpacking and tent camping! I have had my '05 25' Safari since Nov. '05. I am in Florida so the winter weather is not an issue. Problem is a history of the batteries (two 12V deep cell) discharging rapidly when boondocking. Airstream in Ohio checked out the charging system and said all was fine. However, 2 brand new Interstate batteries later, same problem. Now, trailer sitting, with shoreline power. Seems the batteries have a problem maintaining a charge. When the setting was on 'Use', instead of a trickle charge, the batteries heated up and boiled the water out. [eventually leading to their premature demise.] If we, instead, set switch on 'Store', the batteries would drain rapidly; we also tried a 2volt trickle charger on the batteries to maintain the charge. While not overheating, they would not get to full charge. Maybe was too late due to overheating. Now need new batteries again. Why? What am I doing wrong?

[Silvertwinkie]

Batteries and charging is a fairly touchy subject round here.

The fact is that the electrical charging system installed in Airstreams from what I understand is not a 3 stage charging system. In effect from what I've read and heard, cooked or damaged batteries are fairly common situation.

Here is a write up and an upgrade to consider:

Magnetek 6300/7300 Upgrade Kit

I have not gotten new batteries yet for my Safari, but I was not about to get new batteries before upgrading the power unit in the Safari first. I believe the conversion to the linked unit took me about 30 minutes, if that to do.

Deep cycle batteries if cooked will be damaged. Deep cycle batteries that are allowed to go totally dead are most likely damaged. Deep cycle batteries that are left in over the winter (though not an issue in your particular case) will most likely be damaged. If water levels are not maintained, clearly, the batteries will be damaged.

Once damaged, the life cycle and performance would be diminished significantly. When in store mode, it's my understanding that the batteries are not being charged, however parasitic draws (LP detector, etc) still may draw some power and if left in storage long enough, clearly the batteries will go totally dead.

What I like about the 3 stage units is that you can leave it plugged into shore power and when the voltages get to a certain level, the WFCO that is linked will actually back off and not cook the battery, which also solves some of the needs of leaving the unit in store mode.

There are many who feel that sulfur build up would still be an issue and there is even further Chevy vs Ford type discussions about what type of batteries to use. My take is that a properly cared for battery and proper charging system should give the average RVer 3-4 seasons, maybe a bit more, maybe a bit less depending on several factors discussed earlier. Though this may seem short compared to the batteries in cars, you have to realize that the uses are completely differernt. Same holds true for RV tires...even though they may still seem good, after about 4 years, it's time to replace them, and of course similar Ford vs Chevy type conversations are had about tires as well as you can imagine.

[Janets Husband]

Originally Posted by campercan

I am new to trailer life, a jump from backpacking and tent camping! I have had my '05 25' Safari since Nov. '05. I am in Florida so the winter weather is not an issue. Problem is a history of the batteries (two 12V deep cell) discharging rapidly when boondocking. Airstream in Ohio checked out the charging system and said all was fine. However, 2 brand new Interstate batteries later, same problem. Now, trailer sitting, with shoreline power. Seems the batteries have a problem maintaining a charge. When the setting was on 'Use', instead of a trickle charge, the batteries heated up and boiled the water out. [eventually leading to their premature demise.] If we, instead, set switch on 'Store', the batteries would drain rapidly; we also tried a 2volt trickle charger on the batteries to maintain the charge. While not overheating, they would not get to full charge. Maybe was too late due to overheating. Now need new batteries again. Why? What am I doing wrong?

Silvertwinky is totally correct. Todays micro-processor controlled chargers are the way to go. The day of the old "Battery Boilers" is long gone that is why they are so cheap, but in the long run they will cost more. The expense of replacing damaged batteries due to incorrect battery management, is far more than the upfront costs of a intelligent charger.
Use the search function on the forum and look at others comments on chargers. I have personally used the Intellipower 9100 without failure and 4 years on our battery without trouble. Lots of dry camping and the battery has come through like a champ.

[overlander63]

In Florida, car batteries have a use life of about 3 years. RV batteries seem to last about 2 years, depending on use. If you discharge/recharge them a lot, it will seriously shorten their life. Try not to discharge them more then 50%, and recharge them as soon as possible. Keep an eye on water level in the batteries, and add when the level gets low.
Now, to get to the bottom of your current issue, charge the batteries fully on a regular battery charger, not connected to the trailer. If they never get fully charged, obviously they're bad. If they do charge fully, unhook them from the charger, and let them sit 48 hours. Check them at that time. If they are low, they are bad. You can take them to almost any auto repair shop that sells batteries, and ask them to load test them. If they don't pass the test, replace them. If they do pass the test, you'll need o look at the trailer.
Check for a draw first. The easiest way to do this is to hook one of the batteries up to the positive terminal of the trailer (leave the other one out of the circuit). Use a 12 volt test light to bridge the gap between the negative terminal and the negative battery cable. If the light lights, you have a draw. If it lights dimly, it's a small draw. That means it will drain the batteries, but will take some time (days, weeks, even a month or two). If it lights brightly, you have a serious draw. To check for that, leave the test light hooked up, and remove fuses from the fuse panel, one at a time, until the light goes out. That will be the circuit that has the draw. It will narrow down the systems you will have to check.
If removing all the fuses don't remove the draw, you have either a draw in the LP alarm, or the charging system. If it is the LP alarm, it is supposed to be that way, you can disconnect the alarm to remove the draw. Just remember to hook it back up when you use the trailer.
If you disconnect the LP alarm, and still have a draw, it is most likely in the charging system.
This may not fit your exact circumstances, but will give you an idea of how to check your low voltage system.

[bryanl]

see Basic battery guidelines for some ideas. Keep in mind that recharging batteries and maintaining batteries are two different tasks and it is usually the maintaining that suffers.

A good battery maintainer will keep a top charge on the batteries without losing electrolyte and will do 'things' to inhibit sulfation. The PD+CW and WFCO converters do well at this. Another option is the BatteryMinder(tm), a dedicated battery maintainer that uses a desulfation technique first described in HomePower magazine a while back.

If properly used and maintained, you should expect a 4-7 year life from your batteries (re Az WindSun FAQ).