Battery Connection Problem

[Todd Sleeman]

Last month we went camping. The first night we camped in the parking lot as we couldn't get into the camping area. Everything worked fine off the battery (a few lights, the water pump, the fan). The next day after we drove up a bumpy road to the camping area, nothing came on. I had my mutli-meter, and the voltage at the fuse panel read 3.7 volts, and was 12.5v at the battery itself. I figured that there was a loose wire that jarred loose.

Very odd I thought, but solved the problem by bringing the battery inside near the fuse panel and wiring it directly to the fuse panel with some extra wire. Everything worked great for the weekend.

Today I was trying to troubleshoot the problem, thinking I had a loose wire/poor connection. With the AC plugged in, I got 13+volts at the connection for the battery in the front of the trailer. The battery read 12 volts. I hooked up the battery and unplugged the AC power and got nothing. There was no voltage at the fuse panel. I unhooked the battery, plugged in the shore power, and took another reading. 13+ volts at the battery connection.

It seems that if I'm getting 13 volts at the battery connection in the front of the trailer that the wiring is fine. I just find it bizarre that I get no voltage when I connect the battery and check the voltage at the fuse panel in the back of the trailer. I did have the fan and lights switched on when I tried taking a reading for the battery. Is it possible that the load on the battery caused it to drop to 0? Of course, this doesn't explain why hooking it up directly last month worked fine (and why simply driving up the bumpy road caused it to stop working).

Tomorrow I'll hook up the tow vehicle and see if that powers the trailer and what kind of reading I get.

I'm confusing myself just writing this, so I apologize.



Any ideas?

Thanks,

Todd

[Harry Young]

If I understand this right, from the converter to the battery you have 13v, from the battery to the fuse block its craping out going the other way from the battery...The connection at the battery post/terminal is compromised at that point on the (-) or (+) terminals...Your meter is measuring the converter voltage feeding to the battery connections...and yes that establishes that path as good with its ground...Now reverse it the other way and the voltage does not have a good enough connection at the post/terminal to get out of the battery cells to the fuse block...

In my mind that's battery connections...I would clean them, if they are the universal type or are eyelets disassemble them and clean all of the wire/ any contact surfaces with the battery post, clean the surfaces that directly contact physically with the posts/term, examine the wires closely too, the vinyl sheath can look healthy but the wire underneath may be severed from the terminal connector or be attached by only a few strands of wire...Your master fuse links/fuses/or master breaker if present are good because the converter voltage can reach the battery clamp/screw where you can measure the floating voltage as the 13 volts...It does not mean that the voltage you are measuring is reaching the cells of the battery via a compromised connection (post/term) which is why it craps out when it flows the other way...Whatever you find out please post its resolution as I am curious.

Harry

Last month we went camping. The first night we camped in the parking lot as we couldn't get into the camping area. Everything worked fine off the battery (a few lights, the water pump, the fan). The next day after we drove up a bumpy road to the camping area, nothing came on. I had my mutli-meter, and the voltage at the fuse panel read 3.7 volts, and was 12.5v at the battery itself. I figured that there was a loose wire that jarred loose.

Very odd I thought, but solved the problem by bringing the battery inside near the fuse panel and wiring it directly to the fuse panel with some extra wire. Everything worked great for the weekend.

Today I was trying to troubleshoot the problem, thinking I had a loose wire/poor connection. With the AC plugged in, I got 13+volts at the connection for the battery in the front of the trailer. The battery read 12 volts. I hooked up the battery and unplugged the AC power and got nothing. There was no voltage at the fuse panel. I unhooked the battery, plugged in the shore power, and took another reading. 13+ volts at the battery connection.

It seems that if I'm getting 13 volts at the battery connection in the front of the trailer that the wiring is fine. I just find it bizarre that I get no voltage when I connect the battery and check the voltage at the fuse panel in the back of the trailer. I did have the fan and lights switched on when I tried taking a reading for the battery. Is it possible that the load on the battery caused it to drop to 0? Of course, this doesn't explain why hooking it up directly last month worked fine (and why simply driving up the bumpy road caused it to stop working).

Tomorrow I'll hook up the tow vehicle and see if that powers the trailer and what kind of reading I get.

I'm confusing myself just writing this, so I apologize.



Any ideas?

Thanks,

Todd

[Todd Sleeman]

Boy, that seems super obvious! (making me feel fairly dumb) I will check that out first chance I get. I will definitely report back with whatever the solution turns out to be. I'll look at that this evening if I get the chance. The mosquitos have put a hamper on working outside in the evening as of late.

Thanks!

If I understand this right, from the converter to the battery you have 13v, from the battery to the fuse block its craping out going the other way from the battery...The connection at the battery post/terminal is compromised at that point on the (-) or (+) terminals...Your meter is measuring the converter voltage feeding to the battery connections...and yes that establishes that path as good with its ground...Now reverse it the other way and the voltage does not have a good enough connection at the post/terminal to get out of the battery cells to the fuse block...

In my mind that's battery connections...I would clean them, if they are the universal type or are eyelets disassemble them and clean all of the wire/ any contact surfaces with the battery post, clean the surfaces that directly contact physically with the posts/term, examine the wires closely too, the vinyl sheath can look healthy but the wire underneath may be severed from the terminal connector or be attached by only a few strands of wire...Your master fuse links/fuses/or master breaker if present are good because the converter voltage can reach the battery clamp/screw where you can measure the floating voltage as the 13 volts...It does not mean that the voltage you are measuring is reaching the cells of the battery via a compromised connection (post/term) which is why it craps out when it flows the other way...Whatever you find out please post its resolution as I am curious.

Harry