Battery not charging during travel, Micro Minnie 2108DS

[KGs2108DS]

My Lithium Ion battery does not seem to be charging correctly during towing. Yesterday 8hr travel, only refrigerator running on propane ~1.25amps. Upon arrival at destination 65% SOC, 13.11V, -16W, -35.9Ah, 1d12hr remaining. This morning after standing overnight w/refrig 57%SOC, 13.08V, -1.06A, -14W, -44.4Ah, 1d13hr. Connected 20amp Li charger for 1 hr: 56%SOC, 13.08V, 6.22a, -14W, -44.4Ah. The charger is new, and red light indicates charging. It seems to me running a 29amp charger for 1 hr should add 20Ahr to the battery, moving the ending -44.4Ah to -24.4Ah - is this wrong? I do note the charging wire from charger to battery is ~30” long of small gauge wire. At I then d/c the 20amp charger and plugged the shoreline in for 30min getting: 59%SOC, 13.5V, 6.34A, 86W, -42.3Ah. This is running the on-board 6amp battery charger in the WFCO Ultra III Distribution Center WF-8955PEC. I then plugged in solar “brief case” given to me by a friend, and after 2.5hr: 62%SOC, 13.43V, 2.32A, 31W, -39.3Ah. The user manual for WFCO has 4 trouble-shooting notes: a) open inline fuse in battery wire (don’t think my trailer has this), b) open wire between the converter and RV battery (seem like there’d be NO charging whatsoever if this was the case), c) loose ground (hum… possible, but I’m not sure how to check the various grounds), d) improper torques (I’m not sure what this is??). I’m at the beginning of 6 weeks of boondocking, and am a bit worried about this issue. Oddly, the LED display on the MicroMinnie indicator panel (tanks and elect) show the battery to be fully charged 4 LEDs lit. Any help or thoughts would be much appreciated!

[creativepart]

You’ve included a lot of info but much more is still needed.

Is this self installed Lithium, or do you have a FLX trailer with Factory Lithionics? If self installed how many batteries and of what amp size?

What year is your Micro Minnie?

Lastly about your TT’s OEM battery monitor, assuming you do not have a FLX trailer that monitor is a voltage monitor for lead acid batteries that are fully charged at 12.7v. So, with Lithium batteries and their higher resting voltage it would just about always reading fully charged. That gauge would be worthless in this situation.

[Morich]

Do you have ameter to verify that power is getting from the tow vehicle to the trailer?
I like to start with basics and work up when looking at this.
Is the power getting to the trailer connection or has something failed on the front end?
Blown fues when hooking up can be kind of common and means no need to beat up the trailer if the tow is bad!
Is the tehre/connection from tow to trailer making good contact?

There are often breakers under the front trailer frame which can be a problem. There may be some hiding but you may have to lay down and look up like under the propane tank? we get reports of these as a trouble spot at times!

If you look at the battery voltage when the trailer is not connected to tow and then compare what you get when they are connected and the tow vehicle running, you should see an immediate jump if there is charge voltage getting to the trailer.

d) improper torques?
High class way to ask if your screws are tight! Maybe better than asking if you have a screw loose?
Sorry!

[KGs2108DS]

Thanks to both of you! Self-installed, 100Ah LiFeP04 20A 14.6V. I re-routed wiring from tongue to front pass-through cabinet right beside the master switch. Had ample wiring to do this, as was very careful of stressing any connections in the process. My trailer is factory stock. It has WFCO 8955 AD series Power Center unmodified since i purchased it new in late 2018. Model is 2018 2108DS. It is very helpful to know the OEM LED panel indicator is not giving any helpful info. I do have a multimeter w/Amp function. I did have Toyota check everything to the 7pin connector in the past couple of months and all was OK. I think the 7pin connector is making good contact. The trailer lights all working OK, though I suspect it is a different wire carrying juice to the converter, eh? I’m not quite sure how to check that, though last summer the connector got ripped out, and I had to replace the front end of the cable and connector - charging while traveling worked fine after that. What kind of breaker/fuse would I be looking for under the trailer frame. If it is in the 4ga wire, it would have to be pretty noticeable, right? Yes, I will check the voltage reading on the Victron with the tow vehicle running and the cable disconnected, and then connected, and look at the voltage history for a spike. I’m quite sure I have at least 1 screw loose! But, I’ll check the trailer and battery terminals again for torque! Thanks, and get back to you. Thanks again!

[Morich]

A note on what should be standard at the trailer connection on the tow vehicle!
This is looking into the connection toward the car/truck.

Pin 1 for ground and then pin 4 should be 12Volts, some vehicles need the engine running for this.
If no voltage here, you are over into the chassi builder's drawings and it may be a blown fuse. Depending on truck/car model, I expect this to be in a box under the hood!
But you need Chevy, Ford, etc. info to get much of that info!
If you have had trouble with this connector, it may have blown a fuse?

[KGs2108DS]

Ok, here are the results… the voltage with truck running and off was constant at 12.4VDC. There is a 30A fuse in the + line to the elect jack. There is what appears to be a fuse link on the inner chassis up front with two small bolts, one appears to be copper. It has a red plastic cover on it (I’ll try to upload a pic). Made certain ground bolt was tight and tightened battery terminals. Made two adjustments to Victron settings per tech at Victron; charged voltage to 14.0, and battery SOC on reset, to “Keep SOC”. The tech at WFCO stated, “your WF-8955-PEC will take a lot of time to charge - What you need to order is P/N# WF-8955-AD-MBA to make it compatible with Lithium batteries and Auto-Detect charging. I’ve looked this part up, about $200, and there’s a video showing how to switch it out. BUT, my question is that the current technical manual seems clear that the present converter is fully lithium compatible. Back to the 7pin connector and wiring loom. When it got knocked out while towing, and ground down, I replaced it myself with great care and heat shrinkable butt connectors, and a water-proof heat shrinkable section of insulation about 18” long over the splice site. It worked fine thereafter. However in June ‘24 on a trip to colorado the SOC of my 2 older lead acid batteries was showing very low after 8 hr of towing. I stopped at a NAPA d/c the batteries and had them tested - both were at 100%. Not sure how to explain that incident. Further thoughts and trouble shooting recommendations? Thank you so much!

[Morich]

Okay, I think we are getting some ideas when you mention you do have the red boxes, etc, under the frame. They have been a souce of discussion for problems on the forum in the past.
One biggie is that they do not work as they look like and folks have looked at them and not spotted details that are needed. One common complaint is that they are in a terrible locations for getting wet! So a built in corrosion spot?
I do not have drawing, etc. to look at what happens but I do remeober there is a different power route for the jack than for other things like charging!
If there is a metal 4X4 box there, it may also have a tiny little breaker snuggled down in the bottom and hidden by a pile of wires! There may be a tiny button on the side of the as it is a resettable breaker but smaller than most expect. Possible to look right at it and not see it!

We need some of the trailer folks who pay more attention to trailer things to pop in and them may have bookmarked the info on some of these discussions!

I tend to only remember what I find important to what I do and don't remember much about the things I don't expect to ever see!

I did a forum search for 2108DS and got a tub full of posts. That might take a few years to fully sort through but I got semi-lucky and found this post that seems to have possiblegood info. Part of it is a drawing one user has built up. It might be good info if you can pluck out the parts you need to check. One Item I noted was a correction on my idea about the 4X4 box as it may have been changed at some year?
https://www.winnieowners.com/forums/...ds-367061.html

Maybe some help and combined with what you can actually see in person will let it make sense?
There is a group of posts on the trailer group electrical but not where I can find it when I need it. One thin I know is that they keep changing things!

Out of sight? Out of mind if I don't write it down!