BATTERY QUESTIONS/PROBLEMS

[Larry-P]

When I test my battery with the battery dis-connect on it reads 13.3.
With the battery dis-connect off it reads 10.7
Is the battery shot ? Time for a new one ? Battery is only 2 years old. Exide battery.
What's the best brand to get ? Should I get maintenance free or normal battery ?
Thanks,

Larry P

[Tom S.]

Before scrapping it, I would try charging it first to see if it holds a charge, and what the voltage reading is. If it is bad, you have a lot of options available, depending on how much money you want to spend. If you are simply looking for a replacement, chose a battery designed for extended draw like the Optima Yellow top (NOTE: that is not an endorsement for Optima!!! I personally do not like the brand and only posted it for type identification!). If you want to extend the operating time of your battery consider buying two 6 volt golf cart batteries.

[DQDick]

X2 on what Tom says. Folks are using everything from deep cycle marine batteries (we have two and got the best NAPA had to offer) to golf cart batteries to even the batteries that power the road side signs. Just make sure you get a quality one.

[mhs4771]

Just a guess, but from the voltage reading you have, sounds like you have a bad cell in the battery (battery is made up of 6 2 volt cells). But before changing, did you check the water level??

[Larry-P]

I'm confused. When you say to charge the battery, isn't that what the converter is doing within the Monty ? As long as the battery dis-connect is on won't the battery be charged by the converter ?

If you are saying I should charge the battery independent of the Monty unit, do I remove or dis-connect the cables from the battery before hooking up my battery charger ?

Under normal conditions, if the battery is reading 13.3 with the battery dis-connect on, what should the reading be when the battery dis-connect is off ?

Larry P

[hookman]

If you are hooked up you will get a good reading if you are disconnected from shore power or your truck and still 13.3 volts the battery should be good. Take it to a battery shop and let them test it to be sure.

[Larry-P]

It appears I'm going down the road of purchasing a new battery for my Monty.
I've been advised to purchase a AGM GROUP 24 battery.
Any thoughts on going with the AGM type battery in place of the flooded ?
We are not big dry campers so large amounts of battery life is not a big issue. I just need a good relible battery for jacks, fridge, etc.

Larry P

[Tom S.]

quote:Originally posted by Larry-P

I'm confused. When you say to charge the battery, isn't that what the converter is doing within the Monty ? As long as the battery dis-connect is on won't the battery be charged by the converter ?

If you are saying I should charge the battery independent of the Monty unit, do I remove or dis-connect the cables from the battery before hooking up my battery charger ?

Under normal conditions, if the battery is reading 13.3 with the battery dis-connect on, what should the reading be when the battery dis-connect is off ?

Larry P

Yes, the inverter/converter is supposed to charge the battery. Note the word supposed. You wouldn't be the forst one to have one go bad - we had to replace ours about a year after it went out of warranty. To rule out that possibility, charge the battery (by removing the cables as you said) and take it someplace and have it tested. If it's only two years old and does have a bad cell, it might be covered under warranty.

[jwedell]

Your readings are correct. The converter will put out 13.3 volts because that is the charging voltage of the battery. The maximum voltage the battery can have disconnected from the charger is 12.7 volts. The battery is 1/2 discharged at 12.2 volts etc. Everything sounds normal.

[ols1932]

quote:Originally posted by Larry-P

It appears I'm going down the road of purchasing a new battery for my Monty.
I've been advised to purchase a AGM GROUP 24 battery.
Any thoughts on going with the AGM type battery in place of the flooded ?
We are not big dry campers so large amounts of battery life is not a big issue. I just need a good relible battery for jacks, fridge, etc.

Larry P

We've had the AGM batteries in the Montana since October 2003. They've served us well and are still going strong. We have the Lifeline D8 batteries that you can look at here. They are expensive but well worth the money. If I remember correctly, we paid $399 each for two of them. Based on that cost, it averages out to about $45/year for us. They are a worry-free battery. However, I only recommend the D8 batteries if you are a full-time RVer. It isn't a real economical purchase if you are only a now and then camper.

Orv

[Carl n Susan]

quote:Originally posted by jwedell

Your readings are correct. The converter will put out 13.3 volts because that is the charging voltage of the battery. The maximum voltage the battery can have disconnected from the charger is 12.7 volts. The battery is 1/2 discharged at 12.2 volts etc. Everything sounds normal.

The problem is the battery voltage, when not being charged, is 10.7V according to the original post. That ain't normal.

[jwedell]

My mistake i thought it read 12.7 instead of 10.7. The battery is dead. Did you check the water level.