battery questions

radren

Hi,
I recently had my trailer at the dealership for repair work. They let the battery drain all the way down. I have had the trailer hooked to shore power the last 48 hours and the battery is still completely drained. What can I do to troubleshoot to get the trailer charging again?
Thanks,
radren

mawebb

Most battery chargers will not charge a deeply discharged battery. You may be able to start the recovery by having the trailer attached to your TV and ensure that power is being supplied to the trailer from the TV. Once the battery reaches approximately 10 volts, the onboard charger should be able to complete the process. 

radren

I drove the trailer home over an hour connected to the TV and it didn't do anything. My shore power is the house and up till now has charged really well. Could the dealer letting it drain all blown a fuse? What else should I check?

radren

I may be confused here, does being connected to the house/shore power charge the battery? Is the TV the only thing that charges the battery? How else do I charge the battery? I thought being plugged into the house would be keeping the battery charged. Do I need to get a battery tender and put it on the terminals directly to keep the battery charged? 

mawebb

Maybe they removed the 30 amp fuse which is attached to the battery. Check the black rubber fuse holder that is located about 6-8 inches away from the positive battery post. First check to see the fuse is there and if it is, that it's not blown. Using a volt meter to measure the battery is the ultimate test. It should be just under 12 up to about 12.5. If it's bellow 10, you might have issues in recovering it. 

radren

Thanks, I will check it out. 

OzT@b

I'm not sure if this is helpful & I know we have different equipment in our T@b here downunder, but we recently charged our battery by unplugging the battery charger from the ac outlet in the T@b & connecting it directly to our "house" power.

IACamper

You might have better luck doing a full recharge like that if you use a separate battery charger instead of the T@B controller. Or take it to a shop and have them test and charge it for you.

ChanW

I might be remembering wrong, but I thought I remembered that that one of the 12v fuses in the breaker/fuse panel was a "main" fuse?

Radren, Are all of those panel fuses ok?

radren

The fuses in the panel seem to be okay, plus everything works when it is plugged in to shore power. My brother thought things wouldn't work (even on shore power) if the fuse at the battery was blown. I flipped the main switches, my brother's suggestion, to see if I needed to reset anything. How can I test to see if the battery is charging? My voltmeter says 13 when I am on shore power. Off shore power the voltmeter wouldn't even light up. Is there somewhere that will tell me if it is charging or not?  Does anyone know how long should the batteries take to recharge on shore power? If I don't see some improvement in the next 48 hours, I will take it someplace but I would like to learn to troubleshoot on my own, for future reference If I can.
Thanks

Lisa33

Do you have or can you borrow a battery charger that connects to the battery terminals directly with alligator clips?  That should give you a reading on the battery charge and eliminate any potential issues with fuses, etc.  

USWildflowers

radren - I couldn't tell from your comment if you checked the fuse at the battery. I believe everything will work on shore power even if the fuse is pulled at the battery.  Also, where are you checking voltage - at the battery, or at the 12-volt outlet inside? If inside, 13+ while connected to shore power and 0 when not connected is probably what you'd see if the fuse at the battery was bad/gone.  Check at the battery when not connected to shore power if you've got a voltmeter that will allow you to do so.

radren

Thanks for the tips. I am at 13 with voltmeter when plugged into shore power. I will check at the battery and that fuse. A good place to start. I think I have a voltmeter that will tell me something about the state of the battery. 

Michigan_Mike

What type of battery do you have, is it a wet cell battery or the sealed AGM unit?   I've heard that the AGM batteries are sensitive and when fully discharged are like an old mule as they do not tolerate this condition well, are stubborn if you will, do not take a charge and are seemingly dead.  

But voila, there is a trick that will revive them (something I found on the web) and nurse them back to good health!  When an AGM battery falls below 9-10 volts they suddenly refuse to take a charge by any conventional method.  

If you have a conventional lead-acid battery handy, you can connect the AGM battery to it with hard-connection cables (not jumper cables) and then hook up a battery charger to the lead-acid battery and turn the charger on. 

Charge current flowing through the lead-acid battery is then accepted by the AGM battery. And since these spiral-wound batteries cost around double what a conventional L-A battery does, its certainly worth giving it a try before junking what appears to be a dead battery.  

If it were me I would pick up a couple of the heavier gauge battery cables at your local Walmart or auto parts store and give this a try as it's much cheaper than buying a new battery.  Walmart should have them as they have an assortment of them listed online.  

mawebb

When a battery AGM or flooded fall below 10 volts or so, modern chargers assume that a 12 volt battery is not present and will not output any charging current. Putting a good battery in parallel will cause the charger to start charging. As I said in an earlier post, connecting the TV and running for a bit will accomplish this without the need to acquire another battery. I am still of the thought that the issue is with the 30 amp fuse at the battery, or possibly the dealer disconnected the battery when the T@B was in the shop. 

leenscottfl

I had a problem with my on board charger. Although the 40 amp fuse appeared ok I noticed that when I touched it the fan would start. When I removed my finger it would stop. Changed what appeared to be a good fuse and that problem was solved. Now after dropping into float mode it will not go back to full charge. Guess I'll just have to find someone to will do warranty repairs for me.

radren

I flipped the main fuse box switches and it seems to be charging now. I have two 6 volt rather than a single 12 volt battery. I am still going to check the 30 amp fuse. Just went to harbor freight to get a box of fuses so I will have spares with me from now on.
Thanks everyone for all the suggestions. 

radren

Just found the 30 amp fuse burned thru, it is on one of the batteries. I replaced it with another 30 amp fuse. Does anyone know approx how long it would take to charge, assuming it is charging now?

ChanW

Full charge from 'dead', at least 12 hours, I think.

mawebb

Yes 12 hours should be correct for approx. 80% charge. Give it another 6 or so and you should be at 100%. 

Rollingztone

I severely discharged my 12-volt Interstate deep cell battery by leaving the 3-way refrigerator on electric while waiting hours for repairs while on the road in Wyoming last summer. No amount of driving after that (6-8 hours) did anything to recharge it. That evening at a dry campground I jumpered it to my truck battery for about half to 3/4 hour with the engine running and it charged back. Then it re-charged normally during driving from then on. Later I had the battery checked at an Interstate Battery shop and it was perfect according to the the guy who tested it.

radren

Thanks everyone. I think I am up and running. Going camping this week but will have power just to be safe. Love to be out in my T@B!

Rad

radren said:

Just found the 30 amp fuse burned thru, it is on one of the batteries. I replaced it with another 30 amp fuse. Does anyone know approx how long it would take to charge, assuming it is charging now?

Are your 6v batteries completly dead.  The reason I ask, one draw back of the 6v system (I have them in my wife's power chair) is sometimes it can be very difficult to get them to take a charge when completly dead.  If yours fail to charge, do an Internet search for charging dead 6v batteries, there are some tricks out there.  I wish I had known about the tricks, I bought new ones when it happened to me....ouch.

AJLilchick

I just changed out the 30 amp fuse which is attached to the battery. Check the black rubber fuse holder that it is located in pull it out and put in a new one. I also went inside the Alde boiler area under the seat and into the switch box and pulled out the plugs in and re plugged them back in. 

jgram2

@AJLilchick, the comment before yours was posted in April 2015. I hope they got it figured out! But it was good of you to offer your experience, that's how most of us learn solutions to our problems!