Log In | Register
Skip to main content
Topic: Rig not fully switching to 12v after being plugged into shore power? (Read 1026 times) previous topic - next topic
0 Members and 1 Guest are viewing this topic.
Re: Rig not fully switching to 12v after being plugged into shore power?
Reply #25 –
Hi Don,
I think it's just a case of overfilling the batteries from time to time over the past 11 years. The red plastic fins of the switch have also become brittle and snapped off. I've taken to using a neutralizing spray, and that has stopped the out-gassing corrosion. I almost always find a bit of water on the batteries, but no matter how low the water level is (while still keeping it above the lead plates), I still get a bit of water condensing out.

David G.
2005 MB
Re: Rig not fully switching to 12v after being plugged into shore power?
Reply #26 –
I'm now thinking I should also replace my 6 year old batteries. Are people still advocating the Trojan T-105's?

David G.
2005 MB
Re: Rig not fully switching to 12v after being plugged into shore power?
Reply #27 –
I recommend doing a voltage drop test starting at the batteries and going as far as you have access to the wiring.  It isn't a difficult test to do if you volt/ohm meter and there are lots of good instructions on you tube and various other free internet sources.  This may assist you in finding which component, or several are contributing to the problem.

Anecdotally, I spent nearly 40 years working in and on the ocean.  It is a terrible environment for electrical systems.  A few years ago, I was anchored in a remote cove at one of California's offshore islands and was not able to start our diesel one morning.  No AAA, Boat US or Vessel assist  65 miles offshore. A careful voltage drop test discovered a slightly loose connection at one of the start batteries and a big voltage drop at the battery cutoff switch.  Tightened and cleaned the connection, and sprayed contact cleaner into the guts of the cutoff switch and exercised it for a few minutes and the diesel started right up!  Nice sound.
HD
2014 27 MB
Towd: Either the Jeep Wrangler or trailer containing the BMW R1200GS and 2 E-bicycles
Happy wife=Happy life
Re: Rig not fully switching to 12v after being plugged into shore power?
Reply #28 –
Quote from: David Gardner  - 
In looking for a new battery cutoff switch (as in the above link), I've noticed that none I've found online or in RV stores, come with the narrow board that the switch attaches to and slips in between the batteries. I could try to reuse the old one, but it is deteriorating and I'd rather replace it as well. Is there a resource for these?
I assume the Mothership made the boards, used with the battery switches.
As Don suggested, a thin piece of plywood should work or piece of thick plastic sheeting.
If plywood is used, coating it with paint or epoxy would be a good idea to prevent rotting.

Larry
2003 23.5' Front Lounge, since new.  Previously 1983 22' Front Lounge.
Tow vehicles  2020 Jeep Wrangler Rubicon, 2001 Jeep Cherokee
Photo Collection: Lazy Daze
Re: Rig not fully switching to 12v after being plugged into shore power?
Reply #29 –
Trojans are fine. I have four years on a set of batteries I got from a golf cart dealer. I took a scale with me and they weighed the same as the Trojans. What does that mean? I don't know. But, it does mean I have the same amount of lead and it cost half as much. Costco is another source for those not demanding Trojan's.

With the money saved you could get a Profill to water your batteries and do use the paper towel soaked in baking soda. Really cheap and works.
Don & Dorothy
Sold our LD in June of 2023

Our boring always non-PC travel blog
Traveling Dorothy
 
Re: Rig not fully switching to 12v after being plugged into shore power?
Reply #30 –
Not so long ago Larry Wade mentioned that when a battery disconnect switch (an LD option) goes toes-up the 12volt system may exhibit some strange behavior. I got that behavior four years ago and traced it to the battery disconnect switch. I just removed it and forgot about it until Larry posted a link to one on Amazon (above).

I ordered the switch and installed it today. Thanks Larry.

PS I tried to find the post Larry originally made about this. I found messages about battery disconnect switches going back over a decade, but not the one I recall. I could not find anything on the subject in The Companion either. It appears to be a misunderstood part and one that fails with some frequency. Maybe someone will send a concise article on it to me for The Companion. Yeah, I will beg.
Don & Dorothy
Sold our LD in June of 2023

Our boring always non-PC travel blog
Traveling Dorothy