12 Volt Problems

[arkaussie]

I'm hoping for some ideas here to solve this problem.

We bought a 2 yr old Horizon 2 yrs ago in Florida and after camping there for a month or 2 we drove to NY for our summer job. I noticed the (original) house batteries were not holding up well overnight at Flying J's so on the way back to Arkansas at the end of the year I installed 4 new golf cart batteries as I expected the batteries to be the problem.

Well turns out they were not the problem but I do not know what is. After 18 months with mostly being parked the problem of no capacity for dry camping is still there. The voltage is above 13 and the inverter seems to be doing it's job plus the specific gravity of all the cells is good. It seems that neither the inverter or the alternator will give the batteries what they need to last for one night of minimal use, say 250 watts for an hour will put the voltage below 12.6 and a couple more hours it will be down to 11.8.

The inverter seems to go thru the stages of charge and floats at 13.5. If I shut everything down I can get the inverter down to 50 watts but it is usually at 100 watts when I dry camp. I do not have to put much water in to the batteries and it looks like I have the original engine batteries. I installed a Trik-L-start for the engine batts so that is always a small draw.

[arkaussie]

I'm hoping for some ideas here to solve this problem.

We bought a 2 yr old Horizon 2 yrs ago in Florida and after camping there for a month or 2 we drove to NY for our summer job. I noticed the (original) house batteries were not holding up well overnight at Flying J's so on the way back to Arkansas at the end of the year I installed 4 new golf cart batteries as I expected the batteries to be the problem.

Well turns out they were not the problem but I do not know what is. After 18 months with mostly being parked the problem of no capacity for dry camping is still there. The voltage is above 13 and the inverter seems to be doing it's job plus the specific gravity of all the cells is good. It seems that neither the inverter or the alternator will give the batteries what they need to last for one night of minimal use, say 250 watts for an hour will put the voltage below 12.6 and a couple more hours it will be down to 11.8.

The inverter seems to go thru the stages of charge and floats at 13.5. If I shut everything down I can get the inverter down to 50 watts but it is usually at 100 watts when I dry camp. I do not have to put much water in to the batteries and it looks like I have the original engine batteries. I installed a Trik-L-start for the engine batts so that is always a small draw.

[jimandsue60]

Are you leaving the 2000 watt inverter on all night when dry camping?

Jim

[Sammie]

How much of a draw does the inverter pull by itself?

[arkaussie]

I do leave the inverter on all the time and I believe it draws about 50 watts or the display shows that which I believe is the minimum reading and it jumps in 50 watt increments so not too accurate.

The batts have gone flat after about 4 hours of the evening so all night is not really my problem.

[jimandsue60]

I have tried to leave my inverter on all night also. It will drain down my system by morning 11.8-12.2 volts depending on outside air temperature. My tv satellite receiver is on when the inverter is on. I have 4 lifeline agm batteries.

I think that the display is not displaying the amount of power that the inverter is actually using but only shows what it is providing. I do not know how many watts or amps the inverter itself uses, my guess is at least 2-5 amps if not more.

I have a second dimensions display and control panel that I have mounted in our bedroom. So when we are dry camping we can leave the inverter on to watch tv and power the satellite system. We can then shut off the inverter when we want to sleep.

Do you leave the inverter on for any particular reason?

Jim

[hamguy]

Go to Sears and spend $95 for their AC/DC Clamp-On VoltOhmAmp meter. It will give you the quiescent current draw plus any other electronic measurements you want.

Also, the voltmeter reading after the batteries are in use a while will read lower than the actual voltage. My panel meter for my 2-6V batteries reads ~11.8 after a night of use.

If I kill the battery power, they rise up to 12.5 or 12.6 within about 1/2 hour.

In addition, many LCD meters for reading the battery voltage read artifically high by about 0.5 VDC. This is, as I see it, due to using the same voltage for operating the meter that it is measuring. You can buy (more expensive) metering that compensates for this error.

[W8RLM]

Lindsay,

I didn't see a description of what you are trying to run. I know that if I leave the refrigerator on AC overnight, it will draw my batteries down. I switch it to LP. If you leave it on AUTO, it will default to AC if the inverter is on.

The old trick of pulling fuses circuit by circuit to see what is drawing the current is still a good idea.

If you still suspect the batteries, disconnect them from each other and see if one goes down rapidly. If so, bad battery.

Good Luck

W8RLM - Bob