House Battery Help

[b1barnes]

Looking for suggestions on our House Batteries. After the winter they were low on juice and plugging in has not charged them up after a couple of weeks. Plugged in everything 12 volt works fine except the stairs will only extend and retract if I either start the coach or push the batter boost.

Where to start....

[markb5900]

Sounds like they are just "dead".
To test it, hook up other batteries and see if everything works.
If it does? Then you just need a new battery. If things don't work, you have other electrical issues.
When starting your coach, it is running off your alternator then most likely and that is why everything works fine.

[Crockett]

I assume you use the bat boost to start the coach? steps should be on the chassis battery side. How many years on the batteries? you check the water??

[mbtelguy]

The way FR wires the battery disconnect switch it can be misleading.
If the switch has disconnected the batteries the batteries will not receive a charge.
The lamp on the switch only indicates there is power on the 12V distribution bus not power to the batteries from the converter.

[b1barnes]

The engine battery is fine. Just used the Bat Boost button to extend or retract the steps.

Water in bats are full.. Connections clean and tight. So I started the engine and cycled the batt disconnect switch so it is in the on connected position and let it run for 30 minutes. When I shut off the engine the batts had picked enough charge to keep the lights on the batt connect/ disconnect switch on, so I plugged the coach into 110 to see if that keeps the charge going. Didn't realize if the batts were disconnected they would not charge.

Found a wiring diagram on another post so on the weekend I can trace everything out. Now that i think of it the batteries were not recharging last fall like I thought they should.

Thanks for our help....

[drivmsafe]

It's a good idea, since MH's aren't used sometimes for weeks, or even months, at a time, to invest in a battery charger/tender. If I know we won't be using "Beasty" for a while, I hook the charger/tender up and it keeps the batteries charged. That's not to say that proper maintenance should not be used.

[b1barnes]

I did hook up a battery charger, but got nervous as the battery disconnect box kept clicking so the battery charger would show a draw of 6 amps and then click down to 3 amps. About every 30 seconds.

Checked to see that nothing in the coach was running or on, plus the coach was disconnected from 110. Thought about disconnecting the batteries, but it started to rain so I did the engine start process noted previous.

Unless someone says this is ok, hearing it cycle just made me nervous as it just did not seem normal.

[drivmsafe]

I normally do not have the battery disconnect switch in the on position when I charge the house batteries. No need to disconnect the batteries. If your battery charger is a charger/tender and has an automatic overcharge sensor, you should not have any problems. If after a good charge and the batteries will still not hold a charge, especially if the disconnect switch is off, then your batteries probably need to be replaced.

[camaraderie]

B1B... You've without a doubt damaged your batteries by allowing them be completely discharged. But...you need to now charge them to 100%. If you are plugged in...you can do this with your converter AND the battery cut off switch to ON so that you can see your overhead 12V lights come on. Leave plugged in to your converter for at least 24 hours....then disconnect the NEGATIVE battery wire for 24 hours. Then go back to your battery posts with a voltmeter and you should measure 12.6 or 12.7 Volts if you were able to take a full charge. Anything less is battery life lost and anything less than 12.4 indicates significant damage. You can still use them when plugged in and for brief periods of use... but I wouldn't boondock with them.
Anything less than 12.2 and you should be making a trip to walmart for some new ones.
Good luck with the recovery. Suggest you get one of these cut off switches for the future to insure the parasitic loads that still exist when you have the batt cut off engaged (propane detector, station presets etc.) can no longer hurt your battery.
Always leave the coach with a 100% charged battery.

Walmart, Amazon & Ebay have them for under 7 bucks.

[Timtation]

Probably doesn't apply in this case but I have had batteries well discharged that would not be charged by my charger. I would parallel that battery with another that was in reasonably good charge, start the charging cycle and after several hours disconnect the "good" battery and the down battery would then accept a charge and cycle out. If you have a smart charger that will do a desulfate cycle you may be totally back in business. Good luck, tim

[b1barnes]

Thanks everyone for the input and suggestions. After getting the batteries started on charging from an external charger and realizing from your input that the disconnect switch must be on to have the converter charge them. Last evening they were showing charged after disconnecting the 110. I put the 110 back on and will let them charge to this weekend and then I will test the voltages like was suggested.

Silly me to believe that disconnecting the batteries didn't really fully disconnect them. I like the simple device that was suggested so I can fully disconnect the batteries from all potential draws. Also if the batteries are fully dead, the disconnect switch will not work even if plugged into 110.

Hopefully the battery voltage will show good and I will also load test them to be sure.

I am also going to add a Shore connection next to where I park the FR3 so it can remain connected without cords going across the driveway.

Thanks again to all the help and suggestions.