Dead battery

[msmst25]

I just returned from the Beverly Beach Bash, and I noticed right before the trip that my battery was dead. The trailer had been sitting for about 3 weeks, and I didn't think much of it. I hooked up to my 30 amp outlet before the trip in order to cool down the fridge, and used the trailer on electrical hookup during the 2 night trip. I assumed that when I got home the battery would be fully charged (it's a 2005 Safari), but the battery is still dead. I took the battery to an electric shop in town, and they fully charged it and tested it, and it seems to be fine. I was wondering if there is an easy way to check with a multimeter to see if the battery is getting any charge from the trailer while hooked up to an outlet. Thanks for your help.

[87MH]

Originally Posted by msmst25

.... an easy way to check with a multimeter to see if the battery is getting any charge from the trailer while hooked up to an outlet.

When the "charger" is hooked up you should be getting around 13.5 volts at the battery terminals. Something less when the 110 is removed.

You may also want to check the battery voltage with the 110 off, the umbilical hooked up, and the TV on fast idle.

You may be surprised how much voltage is lost through a too small charge line.

Luck.

[guy99]

Un-plug the trailer and run some lights for a few minutes (to remove 'surface charge') check the voltage at the battery. Should be around 12.6. Now plug in the trailer and check voltage at the battery. You should get at least 13.2. If you don't, check your 120 Volt breaker box to see if any are tripped. Might be a good idea to reset them all. Now measure voltage at the battery if you've got 13.2 or so you're golden (except for finding out why the breaker tripped). If you are still at 12.6 or below, you have a problem.

[68 Overlander]

Dennis and Guy are both correct. Only thing I would add is that if you discharge your battery below about 80 percent state of charge, it will take a little while before the charger and battery read the same, less a little voltage drop. The battery might read a 10th or so less.

[5cats]

Sounds to me like the battery disconnect switch is activated (set to "store" versus "use") preventing on-board charging, despite being "plugged in".

Cheers,
-jd.

[lewster]

Originally Posted by 5cats

Sounds to me like the battery disconnect switch is activated (set to "store" versus "use") preventing on-board charging, despite being "plugged in".

Cheers,
-jd.

jd,

You hit the nail on the head! If the battery disconnect switch is in the 'store' mode, there is a solenoid that will cut the battery off from the rest of the coach, including the converter, thus not allowing any of the charging voltage from the converter to reach the battery.

Be sure that the disconnect switch is in the 'use' position. You should activate this switch with the trailer disconnected from shore power, as the light comes on as soon as you plug in and you will not be able to tell which position the disconnect is in.

[rseagle]

Also be aware, that if you put the switch in the "Store" position and your battery's voltage drops below 10.5 VDC, even turning the switch to the "On" position and hooking up to shore or vehicle power will not activate the solenoid. In this case, you had to charge directly to the battery with an external charger and not through your trailer. Your electric shop did just that.

Airstream doesn't mention this in the Owner's Manual. My Airstream Tech told me when my battery died.