RE: 2nd Dead Battery.....Help

MtnCamper · Mar 12, 2003, 10:25 AM

cowboyCowboy, Do you have a multimeter, or some kind of volt meter?

Plug the trailer in, and read the battery.
It should be somewhere above 12.6Volts, (if the converter is working)

If you have a digital multimeter, (red is positive) the number should be a + read. If it s wired backwards, (at the converter or battery) it will be a minus read.

Next move to your tow vehicle and repeat this.

QuoteORIGINAL: cowboy

I went out to the Camper 2 weeks ago and NO 12 volt power, the battery read 0.475 Volts. The shore power was connected until the day before and all systems were working.

The battery reads 0.386 Volts,

I m thinking, something is backwards. It would be hard to drain a battery that low (overnight) and not realize something was on. You could even disconnect the neg. terminal and read across the wires, from the converter to the positive post and to ground. See what you got.

mike4947 · Mar 12, 2003, 10:35 AM

cowboyIf it were me, I d be digging out my $15 multimeter from Radio Shack and searching the 12 volt system from the battery through the rest of the PU checking for shorts, blown fuses (shorts lead to blown fuses), bare wire (likely cause of intermittent shorts like while traveling). Especially around areas where wires pass through something.
It doesn t take much of a bare spot to drain a battery while driving with it bouncing around shorting out each time it touches. A lot of times the draw is light enough with the small contact it won t blow a fuse or is in an area where there s no fuse protection, like from the battery back to the converter. That why I installed a circuit breaker right in the battery box. It along with a disconnect fit right in the plastic box. If I plug it in now and the curcuit breaker pops I know I ve done something stupid again.[&:][:@] Since you ve got an inline fuse use a meter and check for a draw with everything off and have some friends rock the PU while you do. Stranger things with electrical systems have hapened (ussually to me).

chasd60 · Mar 12, 2003, 02:09 PM

cowboyMine has a separate circuit for charging the battery than it does for operating the 12V appliances while plugged in. I have an in-line fuse on my battery charging circuit as well as in the converter line that feeds the battery (double fused). If you have 12V while plugged in it does not mean you are getting it from the battery, but maybe directly from the converter. Check your converter output right at the battery terminals with the battery disconnected. It should read upwards of 15-16V depending on the converter. Make sure the hookup of the second battery was with the polarity correct by measuring your converter output in reference to a known ground.

Charge the battery with a regular battery charger, reattach the battery with the polarity correct and put your meter in series with the battery cable and set it to DC current, this will give you and indication of any draw and the magnitude of it. This is done with the converter off(no shore power). If the draw is significant, start unplugging fuses from your 12V side of the converter until you isolate which leg has the power draw and from that point you can see which items are without power. One of those items could be the culprit.

As far as the LP gas detector, I rewired mine to be in the galley cut-off switch. When the camper is closed up and if I have a LP leak I am very unlikely to hear the beep which won t be for very long because it will draw the battery dead. It was the source of discharging my battery after a week or so.

mike4947 · Mar 12, 2003, 04:21 PM

cowboyChas, sorry to say this but that seperate curcuit for charging the battery is just two more wires out of the converter. Plus if you re getting 15 -16 volts to operate the 12 volt section of your PU you should have the converter checked. If they ve went to the trouble to put two seperate transformers in the converter for apx 13 volts for the power curcuit and 15-16 volts for a charging curcuit, battery chargers that output that much do it only for a very short period during charging as it will boil a battery and outgassing and heat are two enemies of batteries.
No one, I repeat No one, makes a converter with a charger that will correctly charge a deep cycle battery.

chasd60 · Mar 12, 2003, 06:28 PM

mike4947

QuoteORIGINAL: mike4947

Chas, sorry to say this but that seperate curcuit for charging the battery is just two more wires out of the converter. Plus if you re getting 15 -16 volts to operate the 12 volt section of your PU you should have the converter checked. If they ve went to the trouble to put two seperate transformers in the converter for apx 13 volts for the power curcuit and 15-16 volts for a charging curcuit, battery chargers that output that much do it only for a very short period during charging as it will boil a battery and outgassing and heat are two enemies of batteries.
No one, I repeat No one, makes a converter with a charger that will correctly charge a deep cycle battery.

Mike I realize that the separate circuit is just 2 more wires, but if it is fused like mine is and the fuse is blown there is not going to be any charging going on at all.

MtnCamper · Mar 12, 2003, 08:59 PM

cowboyCowboy, You still with us here? What s up?

What have you figured out?

cowboy · Mar 12, 2003, 09:43 PM

cowboyThanks to everyone for all the help.

I plan on following the electrical checkout procedure. I need to replace the battery first, after hooking up to a charger last night, it reads 2.8Volts. I am beginning to think that perhaps the last batch of batteries at the supplier had a factory defect.

The great thing about the forums is that all the good people rally to help and provide insight. I have to admit that 12 volts is not my area of expertise, but the group has certainly come up with a number of solutions that would not have crossed my mind.

Thanks to all who posted in reply and I ll get back with the results after I check it out over the weekend.

wynot · Mar 14, 2003, 12:19 PM

cowboyIS The refrigerator on the 12V circuit while you re parked? That fridge will kill a battery in hours.

I found out the hard way that you can t rely on either the converter or the TV to get a battery fully charged. Where did I find out? On our first dry camping trip.

MtnCamper · Mar 26, 2003, 10:47 AM

MtnCamperWhat s up?

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