Aluminum Camper Forum

Livin Lite Forum => Camplite and Bearcat Travel Trailers => Topic started by: Paul on June 04, 2021, 08:09:10 PM

Title: 12v not working
Post by: Paul on June 04, 2021, 08:09:10 PM
Hi, I am currently hooked up to power with my 21bhs and I don't have 12v power. When I test with a multimeter at the battery it says 4.86V. I looked at all of the fuse and they seem fine and all the breakers are on. 120v power works fine. The refrigerator lights are on but it doesn't work and the check light is on.

Any ideas?
Title: Re: 12v not working
Post by: GrampaKilt on June 04, 2021, 08:38:59 PM
Hi Paul, if 4.86V is the reading, I would conclude your battery has no energy left and probably need replacing. For example, when a lead acid (LA) battery reads 12.1V it is already 50% discharged and should be recharged. I'm told that by about 10V, an LA battery is essentially dead. Yours is 'dead/dead' :-\. Fully charged batteries run voltages in the 13-14V range depending on age.

A suggestion, if you are running a single 12V battery, this is a good time to upgrade to 2 deep cycle 6V batteries hooked up in series. Costco has the best price. When I last checked, they provided 208 amp hours (Ah) of power. (In reality, you would only want to use up half those Ahs before recharging.) Regards, GK
Title: Re: 12v not working
Post by: charliem on June 04, 2021, 08:42:49 PM
Paul,
Obviously the battery is dead and probably damaged. With 4+ volts nothing will work. My guess is the onboard converter is not charging at all and not supplying 12V. Check the two 30A battery reversal fuses on the converter. They will blow if the battery is reversed even for an instant. As I recall the reversal fuses will isolate the converter while leaving the rest of the 12V distribution panel connected to the battery. If true the battery will not charge and nothing on the12V system will work after the battery in discharged. There is also the possibility that the converter itself is bad. Not sure what brand you have but the old WFCO  units had a pretty bad reliability reputation.
Title: Re: 12v not working
Post by: Paul on June 04, 2021, 09:11:41 PM
I looked again at the fuse and there is one 40A labeled as reverse polarity that seem blown. If I change it will the 12v system still work with a damaged battery? Or should I replace the battery first
Title: Re: 12v not working
Post by: charliem on June 04, 2021, 09:43:00 PM
Paul,
I would at least charge the battery before reconnecting it. The high inrush current of a totally depleted battery might blow the fuse again. Replacing the battery is your call. My guess is it's damaged but it might work well enough for you while shore power is available. That said you MUST verify the polarity before you reconnect. Do this with a voltmeter and Mark the battery leads so you'll be certain next year. RVs seem to utilize a mix of residential (white negative) and automotive (black negative) color coding. The voltmeter is your savior.
Title: Re: 12v not working
Post by: Paul on June 04, 2021, 10:30:43 PM
Paul,
I would at least charge the battery before reconnecting it. The high inrush current of a totally depleted battery might blow the fuse again. Replacing the battery is your call. My guess is it's damaged but it might work well enough for you while shore power is available. That said you MUST verify the polarity before you reconnect. Do this with a voltmeter and Mark the battery leads so you'll be certain next year. RVs seem to utilize a mix of residential (white negative) and automotive (black negative) color coding. The voltmeter is your savior.


Hi Charlie, the color is red and black, currently I have the red on the positive and black on the negative. I can bring the battery home to charge it than reconnect just to get me going while I shop for a new battery.

Thanks!
Title: Re: 12v not working
Post by: Pinstriper on June 04, 2021, 11:23:45 PM
If the battery were removed entirely, I would think you would have 12v while on shore power, so if you don't and the breakers and fuses are all straight, your converter is biffed. That would also result in the reading you are getting. There's just nothing left in the battery, and nothing coming from the converter.

If the converter were good, and the battery just bad, you should get charging voltage levels across the terminals (14v+) while connected to shore power.
Title: Re: 12v not working
Post by: charliem on June 05, 2021, 12:48:14 PM
If the battery were removed entirely, I would think you would have 12v while on shore power, so if you don't and the breakers and fuses are all straight, your converter is biffed. That would also result in the reading you are getting. There's just nothing left in the battery, and nothing coming from the converter.

If the converter were good, and the battery just bad, you should get charging voltage levels across the terminals (14v+) while connected to shore power.
Maybe and maybe not. As I recall the battery reversal fuses protect the converter by isolating it but leave the rest of the 12V loads connected to the battery. If so, and the reversal fuse was blown, the battery would drain to zilch and no charging voltage would be present anywhere; at the battery or inside the camper.
Title: Re: 12v not working
Post by: Paul on June 05, 2021, 01:31:08 PM
Last time I went to the trailer I noticed that the radio wasn't working but there was still enough power to open the lights, probably the reversal fuse was already blown

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Title: Re: 12v not working
Post by: GrampaKilt on June 05, 2021, 01:51:27 PM
What a great forum this is. Thanks for managing it, Paul! So many knowledgeable contributors. I grimace remembering a few years when I assumed a red plastic cap on a battery terminal was the +ve...and couldn't figure out why my 12 volt lights quit working and the 2 fuses on the converter kept blowing. GK
Title: Re: 12v not working
Post by: Paul on June 05, 2021, 08:50:00 PM
What a great forum this is. Thanks for managing it, Paul! So many knowledgeable contributors. I grimace remembering a few years when I assumed a red plastic cap on a battery terminal was the +ve...and couldn't figure out why my 12 volt lights quit working and the 2 fuses on the converter kept blowing. GK

Thank you!
Title: Re: 12v not working
Post by: Paul on June 08, 2021, 10:55:59 PM
I had a very hard time finding a 40a fuse locally, all I could find was 30a. I could have looked harder though just went to 3 stores. I decided to order a pack on amazon. I went to Canadian Tire and got a AGM group 24 battery. I didn't wanted to go up in size or switch to 6v batteries since I didn't wanted to change the box etc. and a group 24 is enough for my need but I decided to upgrade to AGM.

My radio is not working though I though maybe it was because of the blown fuse or that the old battery wasn't charged enough but it still doesn't work with the new battery, everything else work fine.
Title: Re: 12v not working
Post by: GrampaKilt on June 08, 2021, 11:12:09 PM
Hmmm, my converter protection fuses are 30A. I'm not sure if that's because shore power is 30A max or if that fuse rating is just a coincidence. BTW, check the radio's own fuse, 5A??; one has to remove the radio to get at it. Regards, GK
Title: Re: 12v not working
Post by: Pinstriper on June 09, 2021, 12:27:02 AM
Hmmm, my converter protection fuses are 30A. I'm not sure if that's because shore power is 30A max or if that fuse rating is just a coincidence. BTW, check the radio's own fuse, 5A??; one has to remove the radio to get at it. Regards, GK

The fuse will be sized for the gauge of wire and the device it protects. It is possible Paul's fuse was replaced by someone who didn't want the 30 to blow (when in fact it was designed to).

Title: Re: 12v not working
Post by: Paul on June 09, 2021, 07:22:33 AM
Hmmm, my converter protection fuses are 30A. I'm not sure if that's because shore power is 30A max or if that fuse rating is just a coincidence. BTW, check the radio's own fuse, 5A??; one has to remove the radio to get at it. Regards, GK
Thank you I will check that

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Title: Re: 12v not working
Post by: Paul on June 09, 2021, 07:24:31 AM
Hmmm, my converter protection fuses are 30A. I'm not sure if that's because shore power is 30A max or if that fuse rating is just a coincidence. BTW, check the radio's own fuse, 5A??; one has to remove the radio to get at it. Regards, GK

The fuse will be sized for the gauge of wire and the device it protects. It is possible Paul's fuse was replaced by someone who didn't want the 30 to blow (when in fact it was designed to).
I ordered the trailer brand new and took delivery of it the same day it arrived to the dealer so I think they were installed by livin lite but I guess the dealer could had the time to change them. The fuse that is closer to the battery is also 40a weird. Should I replace them with 30a?
Title: Re: 12v not working
Post by: Pinstriper on June 09, 2021, 11:56:53 AM
Hmmm, my converter protection fuses are 30A. I'm not sure if that's because shore power is 30A max or if that fuse rating is just a coincidence. BTW, check the radio's own fuse, 5A??; one has to remove the radio to get at it. Regards, GK

The fuse will be sized for the gauge of wire and the device it protects. It is possible Paul's fuse was replaced by someone who didn't want the 30 to blow (when in fact it was designed to).
I ordered the trailer brand new and took delivery of it the same day it arrived to the dealer so I think they were installed by livin lite but I guess the dealer could had the time to change them. The fuse that is closer to the battery is also 40a weird. Should I replace them with 30a?

You'd have to know whether it was intended to be 30 or 40. Wire gauge plays into it, also what is the rating of what else is connected.

I was just trying to explain why one might have a 40 in place if in fact it was supposed to be a 30 (which would need confirmation beyond GK's assertion)
Title: Re: 12v not working
Post by: GrampaKilt on June 09, 2021, 01:22:37 PM
Okeydokey. My converter is a Progressive Dynamics 4045KV, an older model for sure. The 45 refers to 45 Amps. But what does 45A refer to since, the 110V side is rated for 30A AC and "the DC section has 12 branch fuse holders, two wired to accommodate 30 Amp fuses, ten more with a maximum rating up to 20 Amps each". Aaaah! Exactly what is being protected by those 2 30A fuses? All the other 12V branches? (Since they do insert at a separate location in the DC section.)

While I'm at it, probably one of this forum's vaunted gurus can answer this question. Up to what size inverter can I install given the following: I have 2 6V Trojans, a 60A fuse off the positive terminal (not sure now why I did that), a 50A shunt off the negative for my battery monitor (again, not sure why I went with such a low amperage)? Please and thankyou! GK
Title: Re: 12v not working
Post by: DavidM on June 09, 2021, 01:59:45 PM
Paul: Are the 40A fuse(s) that you are talking about in a pair and not part of the coach's DC fuse line up? Then they are to protect the converter from reverse polarity from a bad battery hookup. Check the polarity with a meter.

Grampakilt: You can put as big an inverter as you want as long as you wire it directly to the battery with the appropriate size wire and protected by an appropriate fuse. Not sure why you now have a fuse in the negative circuit. It isn't required.

Also consider what you are going to power with the inverter. If the TV only then it can be a small 200-300 watt unit and wired with 10 gauge wire and a 30A fuse to protect it. If you also want to power the microwave then it needs to be a 2000 watt inverter connected with at least #2 wire but bigger if it is far away, protected with a 200A fuse.

David
Title: Re: 12v not working
Post by: GrampaKilt on June 09, 2021, 02:22:10 PM
Thanks for your mentorship DavidM! Clarification (I think) it's a 50A shunt on the negative side.

Also can you explain to me (again??) why I put a 60A fuse off my positive?

I'm thinking of a 1000W inverter; plenty to run a blender or those projectors my grandchildren now have. Have you noticed the prices for true sine wave inverters have plummeted? Hence my interest in the install. (Just installed a 1000W in my son's tent trailer--3 teen grandchildren, 10 phones or gadgets, everyone clamoring for charging ports...made sure to use #4 wire.) GK
Title: Re: 12v not working
Post by: DavidM on June 09, 2021, 03:21:36 PM
Oh, I think you mean a 500A shunt. That is the typical rating for RV/boat shunts. I think they produce 50 mV of voltage drop at 500A and that voltage drop is used by the battery monitor's electronics to figure the current going through them. If it sees 1 mV then the current is 10A.

The 60A fuse on the positive side is to protect the wire, probably #10 gauge.

David
Title: Re: 12v not working
Post by: Merlin on June 09, 2021, 05:17:28 PM
I had a very hard time finding a 40a fuse locally, all I could find was 30a. I could have looked harder though just went to 3 stores. I decided to order a pack on amazon. I went to Canadian Tire and got a AGM group 24 battery. I didn't wanted to go up in size or switch to 6v batteries since I didn't wanted to change the box etc. and a group 24 is enough for my need but I decided to upgrade to AGM.

My radio is not working though I though maybe it was because of the blown fuse or that the old battery wasn't charged enough but it still doesn't work with the new battery, everything else work fine.

Paul, just so I am clear, everything electrical in your camper now works fine, except for the radio?
Title: Re: 12v not working
Post by: GrampaKilt on June 09, 2021, 05:57:03 PM
DavidM, thanks to forum, I rewired the mains with #6 or #4. I found it very difficult to squeeze the gauge into the converter's terminals. Attached is a pic of my 50A shunt. I've discovered it's no longer manufactured and a 100A shunt is the lowest sold.

Another question therefore regarding an inverter (1000W). May I ground the inverter to chassis or must I run back to the negative. And if so, before or after the shunt??

Thanks again, GK
Title: Re: 12v not working
Post by: DavidM on June 09, 2021, 06:17:51 PM
Answering your questions a little out of order:

You really want all loads to be on the shunt, so wire a new inverter after the shunt, except see below.

But that brings up another problem. The shunt is presumably limited to 50A (never heard of one that small) and a 1,000 watt inverter will pull more DC than 50A. So either get a new shunt or wire the new inverter before the shunt, but if you do that your BM will not read the true amp hours.

I would never, ever rely on a chassis ground to supply the negative DC circuit for an inverter. Too high a current and lots can go wrong with steel connections. Wire the inverter with + and - wires back to the battery (or shunt as above). Inverters also need to be grounded from their chassis to the RV's chassis but only with 8 gauge wire typically and that ground is meant for safety, not to supply DC power.

PS: Having issued that warning, the 100A starting circuit for my new MHs starter uses the chassis as its negative and it wasn't even hooked up as delivered. It worked because the generator chassis was bolted to the MH chassis providing a return circuit. Go figure. I did connect the unconnected ground wire to the MHs chassis.

Edit: I searched on Amazon and did find a BM with a 50A shunt but it reads in milliamps, not surprisingly. Here is one that I installed in my new MH and has a 500A shunt and has a nice round display, a bit like the Victron for 5X the price: https://www.amazon.com/gp/product/B0824X5MKM/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

David
Title: Re: 12v not working
Post by: Paul on June 09, 2021, 08:21:05 PM
I had a very hard time finding a 40a fuse locally, all I could find was 30a. I could have looked harder though just went to 3 stores. I decided to order a pack on amazon. I went to Canadian Tire and got a AGM group 24 battery. I didn't wanted to go up in size or switch to 6v batteries since I didn't wanted to change the box etc. and a group 24 is enough for my need but I decided to upgrade to AGM.

My radio is not working though I though maybe it was because of the blown fuse or that the old battery wasn't charged enough but it still doesn't work with the new battery, everything else work fine.

Paul, just so I am clear, everything electrical in your camper now works fine, except for the radio?
Yes exactly everything work fine now except the radio

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Title: Re: 12v not working
Post by: Merlin on June 10, 2021, 09:23:50 AM
I had a very hard time finding a 40a fuse locally, all I could find was 30a. I could have looked harder though just went to 3 stores. I decided to order a pack on amazon. I went to Canadian Tire and got a AGM group 24 battery. I didn't wanted to go up in size or switch to 6v batteries since I didn't wanted to change the box etc. and a group 24 is enough for my need but I decided to upgrade to AGM.

My radio is not working though I though maybe it was because of the blown fuse or that the old battery wasn't charged enough but it still doesn't work with the new battery, everything else work fine.


Paul, just so I am clear, everything electrical in your camper now works fine, except for the radio?
Yes exactly everything work fine now except the radio

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Great. It seems the radio fuse must have blown. If you can find and replace it, you should be all set.  Check the fuse panel for a blade fuse for the radio. If it’s good, there may be a separate inline fuse in the radio or the wire going to it.
Title: Re: 12v not working
Post by: Merlin on June 10, 2021, 09:31:40 AM
Thanks for your mentorship DavidM! Clarification (I think) it's a 50A shunt on the negative side.

Also can you explain to me (again??) why I put a 60A fuse off my positive?

I'm thinking of a 1000W inverter; plenty to run a blender or those projectors my grandchildren now have. Have you noticed the prices for true sine wave inverters have plummeted? Hence my interest in the install. (Just installed a 1000W in my son's tent trailer--3 teen grandchildren, 10 phones or gadgets, everyone clamoring for charging ports...made sure to use #4 wire.) GK

Your getting great advice from David. My only suggestion is for device charging. It’s inefficient to invert 12vDC to 120vAC then convert back to 5vDC for usb charging. Better to simply go 12v to 5v with something like this.

https://www.amazon.com/Charger-Adapter-Identification-Multi-Protection-Charging/dp/B0779D7DFG

Title: Re: 12v not working
Post by: GrampaKilt on June 10, 2021, 01:42:00 PM
Paul, I apologize for somewhat hijacking your thread with my questions. On the other hand, I think the answers have been very clear and informative for all. As for the shunt, I had a hunch the low A rating would come back to haunt future electrical plans. And the 500A shunt was just a few dollars more. Called penny foolish? Not all my decisions have been that way; after all, in 2014 I did spend about 7K more for my beloved and 'generational' CL. GK
Title: Re: 12v not working
Post by: Paul on June 10, 2021, 01:44:31 PM
Paul, I apologize for somewhat hijacking your thread with my questions. On the other hand, I think the answers have been very clear and informative for all. As for the shunt, I had a hunch the low A rating would come back to haunt future electrical plans. And the 500A shunt was just a few dollars more. Called penny foolish? Not all my decisions have been that way; after all, in 2014 I did spend about 7K more for my beloved and 'generational' CL. GK
I am glad you did it has been very informative!

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Title: Re: 12v not working
Post by: Paul on August 05, 2021, 09:59:03 PM
I was able to fix my radio! There was a fuse behind it that I replaced(https://uploads.tapatalk-cdn.com/20210806/bd237cc349f527b475d909a199b5c485.jpg)
Title: Re: 12v not working
Post by: Merlin on August 06, 2021, 08:31:52 PM
Great, Paul. Let the tunes roll!