2 batteries die after 2 days of light use

[Kamloops machinist]

    I have a '91 24' Citation Supreme 5th wheel.  I moved the battery from the rear to the front compartment and added a 2nd one in parallel to get lots of amps.  The problem is after about two days of light draw the batteries are down quite a bit for power.  I ran #4 wire from the positive to the back where the main connection is to reduce resistance but I still have a heavy draw somewhere to run the batteries down so fast.  I have checked amperage draw and it is good.  .04 amps is all. Any suggestions would be greatly appreciated.

Rick.

 

[Karl]

Rick,

If you're using standard 220-240 AH deep cycle batteries, you should be using at least 00 gauge or larger wire, but that wouldn't explain your short battery time. At 40 milliamps draw, a charge should last literally months. You should suspect one of the batteries being bad and drawing the other one down. Remove the parallel connection and see how long each battery lasts individually; then replace the bad one. Place a good sized load on the circuit, say 20 amps, to cut down the testing time. That should solve your problem.

 

[Ned]

When using batteries in parallel or series, they should both be of the same age and rating.? If you put a new battery in parallel with an old one, generally the older battery will draw down the newer one.? I would replace the older battery with a new one identical to your second battery.  Test them first as Karl recommends, however.

 

[Gary RV_Wizard]

Just a note: if those are 12V deep cycles, they are likely 85-100 amp-hours each, NOT 220-240 ah.  Only the 6V golf cart batteries deliver 220 ah and you need two of them in series to get 220 ah at 12V.

 

[Karl]

Gary,

Of course you're right I use two Trojans which are in sreies and deliver abour 220Ah. Would like to add two more in parallel, but need to figure out whre to mount them :-\

 

[Tom]

Would like to add two more in parallel, but need to figure out whre to mount them

Karl, you just have to be creative. This is what I did to hold 10 golf cart batteries  ;D

 

[Karl]

Not fair,Tom - that's your boat!

Probably will put them in the same bay as the inverter. Cables would be relatively short and that bay isn't used that much for storage. OTOH, I should check side to side weight distribution to see where they really should go.

 

[John From Detroit]

Not fair,Tom - that's your boat!

Probably will put them in the same bay as the inverter. Cables would be relatively short and that bay isn't used that much for storage. OTOH, I should check side to side weight distribution to see where they really should go.

Putting the batteries and electionics in the same bay is generally discouraged... Fumes from the batteries can do serious damage to the electrnoics (Inverter in this case) The bay next door with a good vapor barrier between them and sealed pass throughs is much better

Source, Expierence and the owner's manual for one of my inverters

 

[Ned]

Use AGM batteries and you don't need to worry about fumes.  You can mount them upside down if necessary.

 

[Tom]

You took the words out of my mouth keyboard Ned  ;D

 

[Tom]

Fumes from the batteries can do serious damage to the electrnoics (Inverter in this case) ...... Source, Expierence and the owner's manual

What happened to your inverter John? Did you have a corrosion problem?

 

[John From Detroit]

That particular inverter has been used once, in testing mode, never put it into service (It is older than the MH)

I have had other gear suffer from being too close to batteries though.  Been working with batteries for a long, long, long time

 

[Tom]

Been working with batteries for a long, long, long time

Me too, both industrially and in boats and RVs, but I've never had a problem.

I have had other gear suffer from being too close to batteries though.

What kind of problems have you had with electronics being too close to batteries?

 

[Karl]

AGM's would be a good choice, but I'd have to buy 4 of them - 2 to replace the Trojans. Not willing to do that. Will build a separator and vent fan w/tubing to exhaust fumes.