Power problem, Battery? PO said it was new.

Ojbikemoto · 03-02-2013, 10:53 PM

Howdy, having a power problem I need some help with! Was leaving Tucson to start my trip back to Oregon and my 12v power is not working. I checked and replaced the circuit breaker under the hood thinking it was bad, which happened before when I was driving across the US. Still not working. Now I have the van plugged in. Yellow light is glowing on the inverter. From what I have read it's charging. Now the 12v lights are working. The inverter is buzzing and the 12v lights are flickering. Is this normal or am I frying my system? I have been driving around so I would think my house battery would be topped off. I am an able mechanic but dumb with electronics. It's a mystery to me. Any advise?

Thanks!!

twogone · 03-03-2013, 07:42 AM

Don't want you going on a wild goose chase, but I just had "weird" electrical stuff happening due to a bad isolator. All is well now. Other more knowledgable members can parse it more closely than me.

time2mtbike · 03-03-2013, 08:48 AM

If you have an volt meter available you can check the voltage coming out of your inverter to see if it is charging the batteries, then you will know what direction to go in (battery side or inverter side).

Ford_6L_E350 · 03-03-2013, 09:41 AM

When you say the inverter is buzzing, I tend to think it is switched on. If left on while the engine is off, it will kill your house battery in short order.

- Step one - make sure the inverter is OFF unless you are actually using AC from it.

- Step two charge your house battery.

- See if the house battery will hold a charge.

Mike

MadScience · 03-03-2013, 10:03 AM

I'd verify that there isn't just a bad connection to the house battery. I'd expect the inverter to be smart enough to not try to charge no battery, but if you have other 12v loads, it might get confused.

If that doesn't solve your problem, then I'd pick up a cheap volt meeter somewhere on the road if I didn't have one with and was in this situation.

(If you're stuck in camp or on a trail, you could probably just steal a bulb from a tail-light and with a metal tool to make the connections, compare relative brightness. Your starter battery is probably good, so that would be a base-line. Be vary careful not to short anything out and not to run a large load across your body -- this is kind of an advanced move that involves some risk, probably best for most folks to stick to a volt meter with nice safe probes.)

With whatever measuring device, I'd check:

1) without the inverter or engine charging (after turning lights on and back off if I was just charging)
- house battery(/ies)
- starter battery(/ies)
- both sides of the separator
- the 12V side of the inverter, or anywhere else where you don't think you're seeing 12V

Compare to this chart:

Voltage charge
12.7 100%
12.45 75%
12.24 50%
12.06 25%
11.89 0%

You'll want to see at least 50% charge for a non-dead battery, close to 100% for one that's been charged.

2) with only the engine charging
- house battery(/ies)
- starter battery(/ies)
- both sides of the separator

You'll want to see ~13-14V everywhere.

3) with only the inverter charging
- house battery(/ies)
- starter battery(/ies)
- both sides of the separator
- the 12V side of the inverter

Depending on your separator, you want to see ~13-14V either everywhere or just on the house side.

carringb · 03-03-2013, 10:14 AM

I would also clean the house battery terminals. Dirty/oxidized terminals can cause LOTS of strange problems, and I've seen my techs chase problems for hours because they didn't start with the basics.

Ojbikemoto · 03-03-2013, 11:52 AM

Thanks for all the good advise! I left the van on sure power last night and it didn't charge the battery. I believe I have a isolator and it looks a bit rusty on top. I'll clean that up and then I will have to drop the house battery to check the terminals for corrosion. Better off doing all that here in Tucson then in the frozen NW!!
Thanks.

**daveb** · 03-03-2013, 01:17 PM

Not saying the writing below is your problem but this is from John Kalmbach when he worked at SMB.

Quote:

Originally Posted by John Kalmbach

The rust you're seeing is probably the culprit for the disharging of your battery and the low battery voltage and charge rate. I have seen this rust issue on older units where the Isolator is mounted horizontal. Another item to check is the 50 amp auto reset circuit breaker mounted under the hood. Trace the wire coming from terminal #2 on the Isolator, it should be connected to this circuit breaker. Water can also enter this circuit breaker causing internal corrosion, and cause major problems.

As Jage has said, you should definitely consider the installation of a Battery Separator in place of your Isolator. SMB West can email you the simple installation instructions, you can see how easy the Separator is to install prior to ordering it if you'd like. The Separator will replace the Isolator and circuit breaker, plus give you automatic "battery boost" from your house battery should the starting battery voltage be low.

John K.

Here is the post:
viewtopic.php?f=14&t=1245

Also if you search "isolator" with "John Kalmbach" as author you will see similar posts.

Good luck.

Ojbikemoto · 03-03-2013, 03:04 PM

Alright, started from the isolator. Got a reading of 14 plus volts, same at the circuit breaker-both sides. Got the Deka gel house battery dropped which was way easier then I thought is would be. The wiring coming to the battery is also 14 plus volts. The battery is reading a low 12.11 volts. Does that mean its dead?? The negative clamp was about to fall off so I think I will clean everything up and try to charge the battery again. All the places that sell big batteries like this are closed anyway.
Thanks everyone, I will post what I find.

Stymlie · 03-03-2013, 04:35 PM

12.11 volts -- isn't that 40-50% charged?