Frustrated with battery install

[Joe Hogan]

1. how do I find a "competent RV electrical technician"? I'm so frustrated bc these guys charged so much and these batteries aren't even mounted to anything, only the inverter and 1 battery is mounted. They didn't design any custom rack to protect any of this. It looks nothing like any install I've seen on YouTube. We just trusted them because they seemed OK on a couple other jobs we had them do.

This is not an easy process. We have spent years sorting through "technicians" to find a few that have very specific skills. Chassis work we go to A, Coach work we go to B, Electrical we go to C, non standard work we go to Z, etc. The hardest tech to source is someone capable of modifying an existing system successfully.

Modifications to any system takes a special kind of person and lots of time to understand the existing system (no matter how simple it appears). Just quickly throw a few parts at it, as you have discovered, is not going to have a satisfactory outcome.

You need to find someone familiar with your Brand and Model of RV, AND has performed this type of modification in the past. (granted this is obvious and not particularly helpful to you.)

Your best bet is to find a way to get your husband interested in completing this task. He is directly impacted by the outcome of the work (directly or indirectly) and will take the time necessary to understand what is required and complete the task correctly.

 

[Kevin D Pem]

As you have figured out the most important part of a DC electrical system is the charging system. Honestly, solar is the best thing you can do, that said, the inverter has circuitry built in to shut it down long before it smokes. I know of no inverters that are not protected for 1.short circuit. 2. over voltage, 3. low voltage. 4.over temp.
You should have a breaker or fuse between battery and inverter, if not fix this!
Your inverter if it is a high frequency type and modified sine wave, will have trouble with heating element type devices, but should still work, but will be much slower, true sine is much better and worth the bucks. Also worth the money if you use the inverter much is a "Low frequency, low voltage inverter".
If modified sine wave you can have other problems:

1 devices that use electronics to change voltage to lower voltage, ie Triac devices, used in mouse control, chargers for things like electronics that don't use a transformer to do the job.
2. because of the lower power level of modified sine, heaters will not get as hot, this includes things like hot plates.
3. quite frequently GFI circuits, spike protectors, and such will get hot and use excessive energy from the battery bank, they may even go into flames.

Ideally It can be said using a generator to charge a battery bank is pound foolish. Solar float charges with out wear and tear on machinery. Batteries (not including Lithium tech) float charge the last 20% of the charge. Using a generator to do this is just wasting fuel. Used panels of the 250w size weigh about #60 about half that of a AGM or flooded 12v 105ah battery. Used panels sell for about 50 bucks for 250w. That makes 100 greenbacks for 500 watts of solar with about 1.5 the weight of one 105 ah lead weight. 500 watts of solar will make your coffee in the morning(not all day). ON THE RECORD! I don't feel anything less than 500 watts can be considered a system, and recommend whatever will fit on your real estate, Mine will hold 2500 watts and I have 2000w. I write this at 8:30AM and my batteries float at 29.5 volts (yes 24v system).

Now for why I posted on your thread. A qualified electrician can fix your 110 VAC system if you need help with it. If you are in Florida Solar installers must be certified. Mechanics that work on electric vehicles understand DC electronics. For the record golf cart techs understand 36v and 48v systems and controllers, this includes battery hook-ups. Contacting Solar companies for installers is a good way to find someone that understands how the complete system works. I am not talking about RV solar, I am talking about off grid cabin installers.

If you find installers that don't want to fix your system it is more likely that they only know one system, and can't help you anyhow. Just a point, don't be afraid to dig into your pockets to fix the system, if you find someone that tells you "No problem, we can get you set up", likely you will like his work.

 

[kangarooelaine]

Update: tech claims nothing is wrong with the system and tried selling us solar panels again.

As a refresher: my RV has less power now than it did with just the regular house batteries that came with it.

I had this installed:
2000w inverter
4x 100 amp hour batteries

It won’t run any appliances AT ALL. Tech tried to claim “running fridge 8 hours will drain batteries.” But I never even got one single hour of running the fridge with these batteries. Not one.

let me repeat:
my RV has less power now than it did with just the regular house batteries that came with it!

I can only do electric when plugged into shore power or turning on the on-board generator.

So now we need to find a new tech. My husband says his conversation with tech was beyond useless, clearly the tech doesn’t understand the problems. It’s obvious to me he barely tested anything out, just plugged it in and claims batteries are now fully charged.

No, I’m not using a generator to charge batteries. I’m plugging in at home or at RV parks to recharge the batteries.

 

[Sonic]

The first thing I would check is voltage of each battery with a multimeter to ensure that the batteries are good and getting fully charged by the inverter.
Knowing which batteries (brand/model/type) you have installed would be helpful information.
After a full charge, let the batteries rest overnight with everything in the coach turned off and shore power disconnected, then measure the voltage of each battery. They should measure 12.7 volts. If not, then check the inverter charge settings to make sure they match the battery manufacturer‘s recommendations.
Optionally If you have a hydrometer, or want to pick one up, I would test the specific gravity of each cell. I do this on a regular basis with my batteries, but its likely an unnecessary complication at this point in your troubleshooting.
If you can report your findings of this initial test, then members can help with further troubleshooting.

One option would be to find a reputable mobile RV repair company to come out and work with you to understand the issue, test your system, and assist with ensuring that your 12 volt electrical system is working properly.

 

[docj]

I'm surprised that no one has mentioned that one serious problem with your current setup is that it lacks the capability to supply the starting current needed to get the A/C compressor going. Yes, the compressor draws ~13 amps when running, but it has a "locked rotor" rating of probably more than 50A and an actual starting load of >30A.

A 2000 watt inverter is capable of providing starting current for the compressor in a residential fridge but not for an A/C. I have a 2.8 kW inverter in my MH and all I ask of it while we're on the road is to run the fridge, which it can do for ~8 hours on our 4-batter bank. My Samsung fridge requires ~11A at startup. I'll bet that the smoking was due to too much current being drawn through the inverter during compressor startup.

 

[Neal]

It all sounds like inverter to me, not batteries.

 

[Fish]

Update: tech claims nothing is wrong with the system and tried selling us solar panels again.

As a refresher: my RV has less power now than it did with just the regular house batteries that came with it.

I had this installed:
2000w inverter
4x 100 amp hour batteries

It won’t run any appliances AT ALL. Tech tried to claim “running fridge 8 hours will drain batteries.” But I never even got one single hour of running the fridge with these batteries. Not one.

let me repeat:
my RV has less power now than it did with just the regular house batteries that came with it!

I can only do electric when plugged into shore power or turning on the on-board generator.

So now we need to find a new tech. My husband says his conversation with tech was beyond useless, clearly the tech doesn’t understand the problems. It’s obvious to me he barely tested anything out, just plugged it in and claims batteries are now fully charged.

No, I’m not using a generator to charge batteries. I’m plugging in at home or at RV parks to recharge the batteries.

I'm kind of confused. Did you have an additional inverter and additional batteries installed in addition to the ones you had before? So now you have 2 inverters and 2 battery banks? As my motorhome sits it has a 2000 watt inverter and 4x220ah 6 volt batteries in it, that's how it was designed from the factory.
The microwave is wired through the inverter but I won't use it off batteries. I for sure wouldn't try to run an AC even if it was wired to do so.

 

[redbaron]

We need to know what model inverter and the size and qty of batteries you have.

A few pictures will tell a lot.

Can you post pictures of the install. Specifically the batteries, showing cables, and the inverter, showing a few angles and the cables.

 

[kangarooelaine]

1- husband is now invested and is working to figure it out. I’m only sharing here now as updates. Husband is very annoyed he has to waste time on this. If he wanted to do it himself we would never had paid someone to do it.

2- specific issue has nothing to do with a/c EXCEPT that if load on system is too high it should have breaker or something to stop it. I’m NOT expecting system to run a/c. I’m frustrated that when a/c was turned on, inverter started steaming instead of flipping a breaker.

3- batteries won’t hold charge and/or inverter is faulty and/or wiring is faulty. Tech plugged in RV and claims the panel read 14 after batteries charged. When we arrived to take RV the panel read 13 and tech has no explanation, says it’s normal and will work. We know it won’t from experience. It will “work” for maybe 20 minutes. Tech isn’t using correct terminology to explain situation & just keeps saying if we need more power we need solar panels, which makes no sense. Solar simply recharges the batteries, and not quickly. Tech refuses to actually investigate situation, isn’t testing batteries etc. He literally just plugged it in a few days, saw panel says they charged, and thinks that’s as much testing as is needed.

4- the install doesn’t even look “neat” and organized. It’s haphazard. It literally looks like a non-electrician type of person of the install, if you know what I mean. Like I’m worried just driving on bumpy roads could knock a connection loose. It just looks wrong - unlike installs I’ve seen on YouTube.

 

[Sonic]

The voltage on your display will change depending on which phase of charging (Bulk, Absorb, Float) the inverter is in during the charging cycle. Even after charging they need to settle down for several hours before you can get an accurate reading. As I mentioned, it’s best to test the voltage with a multimeter at the battery terminals. If they test ok, then you know the inverter is properly charging the batteries.
Then you can begin a rundown test, watching the voltage with a load turned on to see how fast the voltage drops. With a 400 hour battery bank you should get approximately 10 hours out of a 20 amp load until the batteries are down to 12 volts which is typically the lowest you want to go before recharging.

As others have mentioned, it may not be with the batteries or charging system, but it’s good to rule it out before proceeding.