Roadtrek Agile 2015: Shore Power Not Charging House Batteries—Inverter or Wiring Issue?

[sdunn4]

We keep our Roadtrek connected to shore power all winter during outside storage in northern NY. I check to make sure the power is on most every day. The other day I checked the battery level with shore power on and it showed as totally discharged on our indicator panel over the sliding door. Started the van and it read 100% immediately. I checked voltage with a multimeter at the 2 house batteries under the hood with the van engine off- only 5.7 V. So I started the van up and the voltage was up to 10 or so within a couple minutes; then at 15 minutes it was back down to about 7.5 V. Normally the shore power keeps the batteries fully charged; is there a switch located somewhere that may have gone bad? Our inverter is tough to access as it’s under the back bench seat. I am not very savvy electrically but can generally figure most issues out. We did replace the 4 house batteries 3 or 4 years ago and haven’t had any problems. It would seem odd that they have failed so quickly. Any help is appreciated!

Thanks,

Steve

 

[sdunn4]

Update: I’m hoping someone on the Class B forum has had a similar experience as we have right now; the weather warmed up enough to do a bit more troubleshooting today and here’s some more information:
1) our inverter is a Micrgreen Model LW3000-12-C.
2) Coach batteries were changed out in August of 2022 to 4 new 6V Discover Dry Cell EVGC6A-A batteries and we’ve had no issues.
3) today I started with shore power connected, turned on the battery disconnect and then the inverter (normal sequence). “Shore Power On” did not indicate on the instrument panel above the sliding door, and battery level on the panel showed zero.
4) at this point I heard a “clunking” from the inverter that sounded like a relay or solenoid rapidly opening and closing. After about 20 or 30 seconds it stopped, and the battery charge level at the inverter read 45-50%.
5) a recheck of the panel over the sliding door showed shore power on at this point but still zero level of battery charge.
6) I then started the engine and the reading at the panel had jumped to 100%. It also showed 100% on the inverter itself; with 12.3 V in and out.
7) with the van engine off, I had (more accurate today) readings of 6.0V across 1 battery and 12.0V across 2 batteries with my multimeter. With the van engine running I measured 7.9V across one battery and 13.9 across two batteries.

Finally, when we installed the new batteries I switched settings on our inverter from position 5 (charge V=14.4 / float V=13.8 ) to position 2 (charge 14.1 / float 13.4) on instruction from the battery supplier.

I know this is likely too much information but I’m not sure of my next steps and I’m hoping someone has been down a similar path before!

Thanks in advance for any help!

Steve

 

[booster]

IMO, people can never give us too much information about their problem. Usually we get way too little, like "my battery is dead, how do I fix it".

It sounds like there must be an automatic transfer switch in the Microgreen to switch from shore power to inverter and it was slow to activate for some reason and that was the clunking you heard before shore power kicked in.

This may be a long shot, but there were reports of failures of the AC terminal strips where shore power goes into the charger, but I don't recall the years. The connections got hot and melted even on them so that might be worth a look.

You have 4 batteries so unclear where you were measuring the voltages across 1 and 2 batteries. My guess is the they must be wired parallel first and than series so you are checking the common voltage on two batteries as one measurement and then the total back of 4 batteries for the 2 battery reading. The numbers look OK, but we don't know how much current is flowing so not exact on balance.

The % readings on chargers and inverters is generally so far off you can't believe any of it because they just read voltage on most of them. It appears you are seeing 12.0v on just the batteries with no charging or load, and 13.9v with the engine charging, which is OK, but the batteries about 1/2 discharged.

It would be interesting to let it sit overnight and check the voltage at the batteries when they are rested. The plug into shore power and see if the charger starts charging by checking at the batteries so see the voltage. Once you have that unplug from shore power and check the same way with the engine running.

First guess would be the charger as they did have some problems from what we have heard over the years and it does seem to be delayed when compared to the past. The test above should help determine if that is correct or not.

 

[sdunn4]

Booster,

Thanks for your feedback and yes I will go through your suggestions tomorrow morning and let you know what I find. I appreciate the help!

Steve

 

[sdunn4]

Booster,

I just went through your suggested steps:
1) batteries sat overnight; no shore power and readings are 5.8 / 11.7 V (2nd # is for 2 batteries- both are in engine compartment as the other 2 are in the rear tray and tough to access)
2) engaged battery disconnect and flipped shore power on. Had about 50 clunks as inverter worked to turn on, about 45 seconds. Never had that before this week ! Voltage readings dropped marginally to 5.77 / 11.61.
3) shut off shore power and turned battery disconnect switch completely off. Started engine; voltage was 7.70 and 14.95.
4) after 6 minutes, shut down engine and with no shore power and no battery disconnect switch on, voltage was 6.0 / 12.0.

What are your thoughts? Thanks for the help!

Steve

 

[booster]

It certainly would appear that the inverter/charger is failed as the engine charging is still working well and the inverter/charger is also acting odd in start up. Probably time for a replacement.

That setup has long cable lengths and difficult access, so you may want to try start the inverter again, no shore power or engine running and check the voltage at the battery connections at the inverter/charger, if you have access to it. That would make it more certain to eliminate a poor connection someplace.

How are the two batteries under the hood wired together? Look for how a cable or two go between them and to which terminals. That could show how they are wired with the rear.

 

[habsfan59-ClassB]

IMO, people can never give us too much information about their problem. Usually we get way too little, like "my battery is dead, how do I fix it".

It sounds like there must be an automatic transfer switch in the Microgreen to switch from shore power to inverter and it was slow to activate for some reason and that was the clunking you heard before shore power kicked in.

This may be a long shot, but there were reports of failures of the AC terminal strips where shore power goes into the charger, but I don't recall the years. The connections got hot and melted even on them so that might be worth a look.

You have 4 batteries so unclear where you were measuring the voltages across 1 and 2 batteries. My guess is the they must be wired parallel first and than series so you are checking the common voltage on two batteries as one measurement and then the total back of 4 batteries for the 2 battery reading. The numbers look OK, but we don't know how much current is flowing so not exact on balance.

The % readings on chargers and inverters is generally so far off you can't believe any of it because they just read voltage on most of them. It appears you are seeing 12.0v on just the batteries with no charging or load, and 13.9v with the engine charging, which is OK, but the batteries about 1/2 discharged.

It would be interesting to let it sit overnight and check the voltage at the batteries when they are rested. The plug into shore power and see if the charger starts charging by checking at the batteries so see the voltage. Once you have that unplug from shore power and check the same way with the engine running.

First guess would be the charger as they did have some problems from what we have heard over the years and it does seem to be delayed when compared to the past. The test above should help determine if that is correct or not.

Good day Booster, it is funny you mentioned the AC terminal issue...! I had this problem (2016) on my Roadtrek Ranger RT 2014 where the AC neutral lead on the bus bar was loose and causing wires to overheat (due to sparks) Needless to say, lots of intermittent "weird problem" when AC neutral is there/not there...! The inverter (Tripp-Lite 1250) was switching ON-OFF (about every one second cycle) when AC Neutral failed...! Lots of fun times troubleshooting this problem...!

 

[sdunn4]

Thanks for the input! One other question I have is regarding the solar charging system we have. There are 3 solar panels on the roof and “normally” they keep the house batteries charged up. The problem I have currently is that we’ve had so much snow and ice that the panels have been covered most of the winter. I have just recently cleaned them off and we are expecting some warm weather so perhaps I can see if they still charge the batteries. On inspection of the solar system controller it appears that everything is normal.

My real question will show my lack of understanding regarding the electrical system in our 2015 SS Agile- does the solar system wiring tie into the feed cables to the inverter? Or does the solar system directly charge the house batteries? Part of wanting to understand the system is just for the knowledge but if I replace the inverter I’d like to know that the model I choose will integrate well with our system (shore power / solar charging / engine alternator).

Thanks for your help!

Steve

 

[sdunn4]

Update this afternoon-
This morning with no shore power on, our battery showed “1/3” on the panel. The solar panels were cleared of snow and we were expecting a sunny day. When we arrived home after a day out, the battery reading was “2/3”! The solar charging system appears to be working independently of the (probably) failed inverter. Tomorrow I will check actual voltage at the batteries.

I found this generic electrical distribution schematic online (one of the inverter companies’ site); as I don’t have the official Roadtrek schematic do any of you have input on the general accuracy of this schematic?

Thanks,

Steve

 

[sdunn4]

 

[sdunn4]

I’ve found a replacement for the Microgreen LW3000 inverter charger that looks like a pretty good fit. It’s the:

ExpertPower 3000W Pure Sine Wave Inverter Charger | Peak 9000W | DC 12V - AC 110V | LifePO4/ Lithium Battery Compatible | Auto Transfer Switch | LCD Display.

Has anyone used these inverters and what are your experiences? It’s roughly half the price of the AIMS unit mentioned on this forum and sold on Amazon.

Thanks,

Steve

 

[booster]

No experience with that particular item, but there are lots of very similar ones of various brands that look very close the same square shape and length. The Aims, a Renogy, etc are examples. That probably indicates most come from one or two factories and is very common in electronic stuff. They may have slightly different features or quality levels.

It does have all the right stuff like power supply mode, low frequency design, auto transfer (hopefully also for neutral ground bonding), etc.

Amazon shows it at a 4.0 rating with quite few complaints of early failure and horrible customer nightmares.

There was a complaint about killing batteries when sitting so be sure it can be easily shut off completely as it probably has quite high parasitic losses.

It is probably going to be similar to many other of the lower cost inverter/chargers and there is always some risk of early failures or problems with them, but you are looking at a small fraction of the cost of premium, well supported, brands so understandable.

 

[booster]

I think this is the owner's manual for the unit you are looking at.

Manual link

It is a bit smaller than the Aims, but similar to others. Weight at 55# is at the normal lower end of the scale for low frequency inverters. The weight is primarily influenced by transformer size and that also where a lot of cost is. The more expensive Aims is at 68# which is on the higher end of the range. Surge capability and temperature control are both related to transformer size.

The remote if very basic, just on/off for the entire unit and some indicator lights. No display or other control.

They use a kind of odd, and often unpopular, way of handling shore power when you plug in. You may want to read the manual to see if it would drive you nuts or not.

When you plug into shore power it will not turn on and use shore power unless it was already on and inverting, it appears. If it is not on, you need to turn it on after plugging in, and the worst part is that you need to turn it off when you unplug also so the parasitic doesn't draw on the battery all the time. Many batteries have been killed that way. There are chargers out there that turn on when you plug in and go to shore power but turn on inverter when you unplug, which IMO is also not great. I think that with battery banks getting so large they think people want inverters on all the time, but I would prefer they don't do it that way.

With all the brands and the way they come and go in the lower cost import stuff, it is difficult to determine is any given one of them is going to good or bad. Reviews for newer on market stuff are also very commonly paid for reviewers so it is very important when looking at them to be more influenced by low or moderate ones that the glowing list.

 

[sdunn4]

Booster,

Thanks for your feedback and suggestions! Very much appreciated.

Steve

 

[Turtle3]

Have you watched the video Sean at Roadtrek put out? It walks you through the process to check what is bad... whether the inverter, batteries, etc.

Maybe that will help.

 

[sdunn4]

Thanks Turtle,

No I haven’t watched the video; do you by chance have a link to the specific video? Thanks for your input! I would be open to any suggestions and further troubleshooting steps before I actually purchase a new inverter.

Steve