Perplexes Me and Others

[stevanpierce@gmail.com]

I need some guidance in troubleshooting an issue. I seem to be having electrical issues with a myriad of symptoms.

When we first got the RV, there were some issues with the coach batteries not lasting for more than 5-6 hours with minimal load on them. I was told by the dealer repair shop that is really all they are meant to last given everything running, inverter, audio system, lights, etc, etc. So, we trimmed down the fat as much as possible to see if they last any longer; and, they did, but not as much as I thought they would. Not a big deal since this was going into storage for the winter.

Winter comes and goes, during which we took it out a few times to make sure things kept "going", run the generator, etc, etc. We noticed that the batteries were not fully charging correctly and reason that they would need replacing. (We had no idea their history given that this was a purchase from a dealer.)

Came back a while later, maybe a month later...time flies so cannot really tell how much longer than a month to be honest. We found the batteries were dead and took them to Napa to look at since they were Napa batteries...figured that I left something running or the inverter ate power while it sat, all perfectly legit explanations. Come to find out that one actually was dead but the other took a charge. Napa wouldn't honor the warranty since I did not have the receipt. Not a big deal and opted to take business elsewhere. (I thought that I had been away a lot longer than a month, originally 2-3, but looking back wasn't much more than a month.)

We put in two new identical 235ah 6volt batteries joined in a series. Things appeared to be good, but still not the length of time I would expect. I'd say maybe 7-8 hours with minimal amount of stuff running, being really generous. Keeping in mind that I am using the factory control panel to gauge power usage. I know that this is not ideal since they tend to be misleading.

(Yes, I would install a battery monitoring system like the Victron BMV-712; however, I don't want to add to the "complexity" of troubleshooting this issue. The reason behind this....I am using my extended warranty at the dealership and don't want to introduce something new. Plus I suspect it might void my extended warranty.)

At this point, I realized it is probably in my battery's best interest to disconnect the middle connection to the battery series. I didn't want to come back to a dead set of coach batteries. When I went to disconnect the batteries, I noticed that some battery acid had leaked out the top. That too not a big deal since I have heard of this happening if too full or maybe too much of a charge. I did a cursory glance at the power system, nothing seemed out of the ordinary.

A week or two later we took the rig out to a RV site. Plugged it into shore power and things appear to be good. Went to the fridge and noticed that it was on gas and tried to switch it over to AC. What I found is the 5 amp fuse had been blown and replaced it, blew again after 10 min or so on shore. Figured I might have had a "bad" fuse, replaced it, and presto another blown fuse. I soldiered on with my trip and told myself to take it to the dealership under warranty. (The fridge is a dometic 3-way fridge.)

That night I watched TV in the coach and cooked. At some point during cooking, the light above the sink just went out for a few seconds, came back on but still disconcerting. I believe that I was running the microwave at the time.

My rig is a 2010 Roadtrek 210. The only "electrical" things I have done are buy a new TV (after all this bs) and unplug unnecessary or unused electronics, ie stereo/dvd player.

I have another thread where I explained some of my battery issues. https://www.classbforum.com/forums/f...tml#post108078

I have another thread where y'all helped educate me on how long my coach batteries should last....which I really appreciate! https://www.classbforum.com/forums/f...tor-10323.html

If I were a betting man, I suspect that I am going to need to resolve this issue on my own given that the dealer is busy and suspect they are not equipped for electrical work. Having said that, what would you recommend in my bag of tools to troubleshoot electrical issues?

[GeorgeRa]

Originally Posted by stevanpierce@gmail.com

...................

When we first got the RV, there were some issues with the coach batteries not lasting for more than 5-6 hours with minimal load on them. ...............

What do you mean by "minimal load". Did you tried to do load calculation with numbers? Like Battery capacity X [Ah] - Y load [Ah] - Z load [Ah] = ?

[stevanpierce@gmail.com]

Originally Posted by GeorgeRa

What do you mean by "minimal load". Did you tried to do load calculation with numbers? Like Battery capacity X [Ah] - Y load [Ah] - Z load [Ah] = ?

Not that detailed of a load calc, more along the lines of no heavy appliances running, only using the tv without stereo system, no lights on, no ac, fridge on gas, etc, etc. Although determining load calc might be in my best interest in the long run.

[GeorgeRa]

Originally Posted by stevanpierce@gmail.com

Not that detailed of a load calc, more along the lines of no heavy appliances running, only using the tv without stereo system, no lights on, no ac, fridge on gas, etc, etc. Although determining load calc might be in my best interest in the long run.

It is rather difficult to do troubleshooting without actual numbers.
"Although determining load calc might be in my best interest in the long run" and a short one. Good luck.

[markopolo]

Seems like two distinct problems.

#1 - batteries not lasting as long as expected

Check to make sure that the inverter is turned off when not needed. The remote switch for the Tripp-Lite inverter/charger toggles between auto and charge only. Charge only is same as off for this discussion.

Fully charge the batteries. The "high" setting of the Tripp-Lite inverter/charger terminates charging early at around 10A current acceptance. That doesn't result in a fully charged battery. Repeatedly undercharging and consequently repeated partial state of charge cycling shortens battery life.

An ammeter would help you determine if there are phantom loads. Sometimes lights get left on in storage compartment or gear shifts around and turns the lights on so always a good idea to check for that.

#2 - 110V fuse on fridge blowing

Get the model number of the fridge and download a manual and follow the troubleshooting steps. It should have a parts list. A Google search shows it is a fairly common issue. Fixes included replacing the control board and 110V heating element(s).

If you have a multimeter you can measure the heating element resistance to see if it is with spec.

No of us like to just throw parts at a problem but sometimes it ends up being the least expensive and fastest way to fix a perplexing problem when you're supplying the free labor.

[booster]

I hear what you say about he battery monitor and not wanting to give the dealer another excuse not to do anything about the problems (beyond the fact that they don't want to because it costs money or that they don't know how to fix it) but you may want to get the monitor anyway and use it as a removable diagnostic meter. For this kind of stuff you need an high amperage and also very accurate at low amperage meter and that is what a monitor is because of the shunt, plus it will accumulate the usage over time also in a capacity test. I would just rig it up with a short piece of battery cable and the meter part on short wires right with the shunt. Alligator on the power to the meter for the positive cable. Then you could just remove the negative cable from the battery and move it to the shunt and hook the short cable on the shunt to the battery. Clip on the positive and you have a great test meter in place for all your testing. When I did our power upgrades, that is how I had the batteries, monitor, charger setup on the bench and it was very useful in testing everything out.


I think the 5 amp fuse mentioned is a DC fuse? If the 210 is setup like our 190 all the 110v is circuit breakers in the main panel, unless there is a separate small AC fuse in the frig itself. If it is a DC fuse, that would probably point to the control board and that may be your power drain.


As Marko mentioned, the Tripplite will not get the batteries full and some folks will do a final charge with the setting on it to the low switch position to do a more full charge.


If you are looking for a place to start doing something, I think I would just unplug the 110v power and disconnect the 12v power to the frig and see if the drain goes away. You should have a voltmeter at least to monitor the batteries so you don't kill them, cheap at Harbor Freight is OK for that.

[mkguitar]

I have one of the "free" harbour freight multimeters, velcro'd to my house battery for quick and easy checks, it is wired to the poles ( fused)


any system checks need to be done with known, good, fully charged battery. clean the battery, electrons can travel between the poles through dirt/moisture on the casing, causing discharge


once that is set, you can then check


1,) the charging system- how does it charge from vehicle, from shore power?
should be about 14.8 VDC charging




2.) check each circuit for a drain/load above spec




minimize loads


for instance my lights are all now leds- using 1/10th power of incandescents, my "new" TV is DC native ( many of the samller samsungs are- both my 21" and 32" use transformers for home use, they are native 14VDC


sort out the DC before looking at the AC ( like the fridge)



mike

[markopolo]

Re: the fridge problem

This might be the service manual for the fridge:

https://fourwheelcampers.com/NewDome...atorManual.pdf

5.13 fuses
The 3 amp DC fuse is designed to protect the circuit board from internal/external DC shorts. The 5 amp AC fuse is designed to protect the integrity of the AC detection and heater circuit from shorts. On 3-way models only, the 30 or 35- amp DC fuse is designed to protect the DC heater circuit integrity. All fuses can be checked for continuity. If a fuse blows don’t replace it until the problem has been found. If a fuse blows there is a short or component that has created the problem.

Edit: fixed the link

[stevanpierce@gmail.com]

Originally Posted by GeorgeRa

It is rather difficult to do troubleshooting without actual numbers.
"Although determining load calc might be in my best interest in the long run" and a short one. Good luck.

Point well taken! I'm going to work on that sooner than later.

[stevanpierce@gmail.com]

Originally Posted by markopolo

Seems like two distinct problems.

#1 - batteries not lasting as long as expected

Check to make sure that the inverter is turned off when not needed. The remote switch for the Tripp-Lite inverter/charger toggles between auto and charge only. Charge only is same as off for this discussion.

Fully charge the batteries. The "high" setting of the Tripp-Lite inverter/charger terminates charging early at around 10A current acceptance. That doesn't result in a fully charged battery. Repeatedly undercharging and consequently repeated partial state of charge cycling shortens battery life.

An ammeter would help you determine if there are phantom loads. Sometimes lights get left on in storage compartment or gear shifts around and turns the lights on so always a good idea to check for that.

#2 - 110V fuse on fridge blowing

Get the model number of the fridge and download a manual and follow the troubleshooting steps. It should have a parts list. A Google search shows it is a fairly common issue. Fixes included replacing the control board and 110V heating element(s).

If you have a multimeter you can measure the heating element resistance to see if it is with spec.

No of us like to just throw parts at a problem but sometimes it ends up being the least expensive and fastest way to fix a perplexing problem when you're supplying the free labor.

Thanks for suggestions! I have a multi in a drawer somewhere used when I owned a home. Looks like it will find a new place to live in the RV.

I'll sit down over the weekend and read the manual plus troubleshoot the fridge.

[stevanpierce@gmail.com]

Originally Posted by markopolo

Re: the fridge problem

This might be the service manual for the fridge:

https://fourwheelcampers.com/NewDome...atorManual.pdf




Edit: fixed the link

That is the fridge spot on, 2554! I have the original paper manual that is nowhere near as complete as this. Matter of fact, I'll keep the old one for firestarter and print this one out......because paper doesn't need to be rebooted.

[jakegw2]

1.) You need a BMS. For ~$200 the Victron unit will be invaluable for diagnostic purposes as it really is the easiest way to look at current and voltage into and out of the battery. With new batteries you clearly have something going wrong with this current flow. Once you have the BMS you can use the process of elimination (e.g. remove 12v fuses one at a time) to find your issue(s). Also, $200 is pretty much the absolutely cheapest way to get to the bottom of these issue, even with an extended warranty covering most of the work.

Not purchasing one may well end up being penny-wise pound foolish if your brand new batteries end up permanently damaged. As another poster pointed out, you can use it temporarily for diagnosis with a pair of jumper cables used to connect the shunt between the coach negative connection and the battery post.

2.) If you were leaking acid from a brand new battery you either have very bad luck or something is badly wrong with your charging circuit. I'm guessing it is the latter. A malfunctioning charging unit can simultaneously overcharge the battery and cause leakage while also managing to only get the actual charge to about 50-60% of capacity. Lead-acid/AGM batteries need a tapered charge profile to accept a full charge. If something is preventing this tapering profile you will end up damage plus a partial charge. This seems to fit the symptoms you are describing.

This condition is easily diagnosed with a BMS.

[jakegw2]

Also, with a BMS you eliminate the need to do load calculations (which are approximations at best) since you can just read it straight off the display.

[stevanpierce@gmail.com]

Originally Posted by jakegw2

1.) You need a BMS. For ~$200 the Victron unit will be invaluable for diagnostic purposes as it really is the easiest way to look at current and voltage into and out of the battery. With new batteries you clearly have something going wrong with this current flow. Once you have the BMS you can use the process of elimination (e.g. remove 12v fuses one at a time) to find your issue(s). Also, $200 is pretty much the absolutely cheapest way to get to the bottom of these issue, even with an extended warranty covering most of the work.

Not purchasing one may well end up being penny-wise pound foolish if your brand new batteries end up permanently damaged. As another poster pointed out, you can use it temporarily for diagnosis with a pair of jumper cables used to connect the shunt between the coach negative connection and the battery post.

2.) If you were leaking acid from a brand new battery you either have very bad luck or something is badly wrong with your charging circuit. I'm guessing it is the latter. A malfunctioning charging unit can simultaneously overcharge the battery and cause leakage while also managing to only get the actual charge to about 50-60% of capacity. Lead-acid/AGM batteries need a tapered charge profile to accept a full charge. If something is preventing this tapering profile you will end up damage plus a partial charge. This seems to fit the symptoms you are describing.

This condition is easily diagnosed with a BMS.

Both good points, point 2 is timely since I spent a few hours last night watching videos and reading extraneous online sources for charger/inverter issues.

This in turn led me down a rabbit hole...thinking of dual charger/inverters, 1 sole purpose of charge or invert. Another story, another thread!

[mkguitar]

Q: what DO you NEED an inverter for?


DC to AC inverters are wasteful, perhaps not the best use of limited battery power



I have only 2 things in my van which require AC: microwave and air conditioning


Mike

[JohnnyFry]

First off,without tools to measure the battery charge levels and drain you are guessing. You have no way of knowing how long the batteries "should" last without measurments. So, you need a battery monitor. Either a Trimetric (very popular in these circles)or a Victron.
Second: Installing a battery monitor in no way voids your warranty. If they try that game you can sue them and win because they must PROVE that the installing the monitoring system DIRECTLY CAUSED a relevant problem, which it won't, they don't have a leg to stand on.

[RossWilliams]

Originally Posted by JohnnyFry

First off,without tools to measure the battery charge levels and drain you are guessing. You have no way of knowing how long the batteries "should" last without measurments. So, you need a battery monitor. Either a Trimetric (very popular in these circles)or a Victron.
Second: Installing a battery monitor in no way voids your warranty. If they try that game you can sue them and win because they must PROVE that the installing the monitoring system DIRECTLY CAUSED a relevant problem, which it won't, they don't have a leg to stand on.

Uh, no. In the unlikely event that they deny coverage under the warranty, you will likely need to show the problem was caused by a defective part or workmanship covered by the warranty. Which means you will need to get it fixed and then hire a lawyer to recover the cost of the repair. Even if you win in court, you are unlikely to come out ahead in that game.

The reality is that companies don't generally deny warranty coverage unless they really believe it is not their fault. If you bought something from one that does, then you should bail out as fast as possible.

I also don't see how a battery monitor is going to help you find the cause of a blown fuse.

In terms of power usage, I would check the specs on each of the appliances. To start with I would check to see how much power your inverter uses. Our 5000w inverter uses 100 watts even with nothing else on. My understanding is a 3-way fridge uses a LOT of power when on AC - like 300 watts. Those two would drain your batteries pretty quickly by themselves - about 6 hours if the fridge was running constantly.

[mkguitar]

there are a number of online and free app calculators for "Ohm's Law"


By entering the voltage and watts of a device circuit you can get the current draw in amps


rule of thumb, 100 watts at 12 volts is 8.33 amps


( 8.33 but round up for cumulative resistance in wiring, switches etc, closer to 9 )


when running down the road and the alternator is supplying closer to 13.5 volts- current draw drops to 7.4


This sometime explains the "why" of "it works when the motor is running"



handy tool


mike

[Sehc]

Here is a $30 battery monitor. It ill check what you need for now. Victron is much better, but $200. Here is Will Prowse showing off.

https://www.youtube.com/watch?v=E6O76Okmt08

https://www.amazon.com/AiLi-Battery-...language=en_US