Journey with Confidence RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Take a Speed Test Free 7 Day Trial ×
Jayco RV Owners Forum
 


Reply
 
Thread Tools Search this Thread Display Modes
 
Old 06-20-2024, 08:52 AM   #1
Member
 
Join Date: Jun 2020
Location: San Jose
Posts: 56
Lithium upgrade charging confusion - leaving in 2 days!

Hi all, I'm struggling to figure out my charging system on my 2020 Jayco 28BHS. I attempted to upgrade to Lithium batteries for more amp hours and weight savings just before a long camping roadtrip... leaving in 2 days and I'm running into a charging issue.

Background:
* I bought two group 24 Lithium batteries for "drop in replacement". These are specced as 100 amp maximum charge, 20 recommended.
* I swapped out my WFCO WF-8955-PEC inverter/charger (which is 55amp rated) for the WF-8955-AD-MBA, which is their part-for-part "auto detect" to charge Lithium batteries. This was 100% drop in install as well.
* All wiring is the same; batteries are in parallel

I figured I was good to go. Per the WFCO AD manual, I drained the batteries so that it could do a full charge cycle to "learn" what battery type it is, so I am trying to charge from zero (effectively). But when I plugged the coach in this morning to charge, I heard a clicking at the battery area. I checked the app that uses bluetooth to the battery BMS, and I saw that one battery was charging at 45 amps, and the second battery was charging at 5 amps. Per this thread I think the clicking is an auto-resettable fuse that's tripping every 10 seconds or so, then resetting:
https://www.jaycoowners.com/forums/f...ter-54543.html

So now my confusion:
* My TT is 30amps, not 50. Why did the OEM inverter come rated for 55amps?
* Why aren't the parallel batteries charging at the same time? I'd figured both would draw 1/2 the inverter... so about 25amps each. Maybe one lithium battery is "absorbing" all the amperage and it's too much for the fuse, which trips? But electricity should flow equally to batteries wired in parallel, right? (could be the app for the BMS is just wonky too)

Any thoughts on what I could explore or do? My current plan is:
* Is the fuse/relay possibly wired wrong? It is reasonable to me that it would trip at 45 amps... on a 30 amp system. Changing this seems a fools errand. Leads to the question of why there's a 55amp inverter, and why this never happened with the lead-acid batteries.
* Downgrade the inverter to the WF-8935-AD-MBA (35 amp, and I can get it from Amazon tomorrow). I figure I can run other lights as needed and burn off 5 amps and not trip the relay etc. We rarely run the AC on shore power... that would be my only concern on the lower amperage.
* Charge the Lithium batteries on a car charger and get them to higher capacity. Maybe then they wouldn't draw as many amps... but I worry if on the road I'd get to 50% if this would just start happening again.

Worst case, I swap back to the lead-acid and the old inverter for this trip. I may carry them in my truck just as a backup...

Many thanks for any thoughts! I'm really hoping Rustic Eagle sees this! :-)

Photo of battery:
Click image for larger version

Name:	batteries_image_16883969.jpg
Views:	25
Size:	183.9 KB
ID:	94190


Photo of fuse/relay:
Click image for larger version

Name:	relay_image_67182849.jpg
Views:	8
Size:	115.5 KB
ID:	94191
blakei is offline   Reply With Quote
Old 06-20-2024, 10:44 AM   #2
Senior Member
 
Join Date: Oct 2023
Location: Columbus
Posts: 175
The 30a camper rating is for the 120v input. The trailer has a plug for 30a 120v. Ignoring conversion losses, that's 300a 12v.

The converter changes AC to DC and charges the batteries. An Inverter does the opposite.

I would start by replacing the circuit breaker (what you call a resettable fuse). They wear out from use. You may want to check (and maybe upgrade) the cables from the converter to the battery, if they're sufficient, you can upsize to a larger breaker otherwise you should upgrade the cables so you can upsize the breaker so you can use the full capability of the converter.
__________________
-Russell
"You don't get to judge me for how I fix what you break."
2018 Eagle HT 28.5 RSTS/2004 Chevy 2500HD 6.0 MANUAL
Russc25 is offline   Reply With Quote
Old 06-20-2024, 10:44 AM   #3
Senior Member
 
Join Date: Oct 2019
Location: Whitby Ontario
Posts: 598
Its hard to tell from the photo are your battery connections positive in one battery and negative out the other
Attached Thumbnails
12-battery-diagram.jpg  
billcf7 is offline   Reply With Quote
Old 06-20-2024, 10:47 AM   #4
Senior Member
 
craigav's Avatar
 
Join Date: Mar 2017
Location: North Texas
Posts: 3,882
In my response and to keep the math easier to understand, there is commonly around a ~10% conversion loss when converting the voltage from 120v to 12v that I am not going to use in my math.

* My TT is 30amps, not 50. Why did the OEM inverter come rated for 55amps? Your TT is 30A @ 120v (most people just say 30A). Your converter (not to be confused with an inverter) is 55A @ 12V . There is 10 times (10X) the voltage going from 12V to 120V which results in a 10X reduction in the current (amps) coming in. Therefore a 55 amp 12V converter can output 55 amps @ 12V and only input 5.5 amps at 120v. Which means that the 55A converter is only pulling a max of 5.5 amps out of the 30 amps you have coming into the TT.

* Why aren't the parallel batteries charging at the same time? I'd figured both would draw 1/2 the inverter... so about 25amps each. Your images show the wires attached to the batteries but doesn't show how they are wired. Assuming that they are wired correctly and there is no interruption in the flow of current between the batteries (such as the breaker or a fuse), then it is not all that uncommon that one of the two batteries will reach a full charge before the other battery does and in that case the fully charged battery will pull less current than the battery that is still charging pulls. If you disconnect from shore power and run the batteries down a bit (12v fans and lights on for example) and then reconnect the shore power you may find that both batteries are charging close to the same rate with each other.

* Is the fuse/relay possibly wired wrong? Possibly, perhaps more images would help answer the question. By only seeing wires connected it is not possible to know or see how they are wired. I suspect you are asking about the lower image you shared which is of 2 self-resetting breakers and they will click on and off when the current exceeds their rating. It would help if you take the red plastic cover off and see if there is any writing on them indicating what they are rated for.

* Downgrade the inverter to the WF-8935-AD-MBA (35 amp, and I can get it from Amazon tomorrow). Doing this will not help, going back to my first response consider that a 35 amp 12v converter will pull aprox 3.5 amps at 120v (out of your 30A shore power) compared to your 55 amp converter that will pull ~5.5 amps out of the 30A. (these are maximums and will be less, a lot less when the batteries are fully charged).

* Charge the Lithium batteries on a car charger and get them to higher capacity. The only reason to charge them with a car charger is if the converter you have isn't working. While doing this will not cause damage, most car chargers are not designed to fully charge a LifePo4 battery but will charge them commonly to around 80% of full.

Worst case, I swap back to the lead-acid and the old inverter for this trip. Based on what you have shared, I am not sure you have an issue although the clicking on and off should be further investigated. Going back to the Lead Acid batteries and the old "converter" may not be much if any different, especially if there is a wiring issue and that issue goes unresolved.

Other than high level information such as I shared, you really need to have a meter such as the one I shared an image of from Amazon. With it you can check both the AC and the DC current and voltages to help determine where any problems may exists. Even if you are not familiar with such meters they can still be of value and with time understanding how to use it will become more valuable.

I will also add that perhaps more images of where the wires are originating from and going to could be of value as well.

Also, are you always hearing the clicking over and over or just at certain times?

Final thought, perhaps should have been stated first, be careful working with electricity in particular if\when working on the 120v side (vs. the 12v). 120 volts is enough in certain cases to cause great harm up to death (although not that common but certainly can cause the ticker (your heart) to quit ticking) and\or other dangers. ~CA
Attached Thumbnails
Capture.JPG  
__________________
2010 GreyHawk 31SS
craigav is offline   Reply With Quote
Old 06-20-2024, 12:38 PM   #5
Member
 
Join Date: Jun 2020
Location: San Jose
Posts: 56
Wow, Russc25, billcf7, and craigav, thanks for the fast replies!! Very helpful already.

As scary as it may be, I consider myself above average at wiring and electrical, doing lots of repairs and upgrades around the house etc. However, I CLEARLY can’t claim to be good at the math for electricity! And, I will take the advice to always be careful.

Thank you Russc25 and craigav for clarifying the 120v/30a input v. 12v/55a output math. My takeaway is that there’s theoretically up to 12v/300a available from the 120v/30a input.

To answer craigav: I get the clicking/resetting as soon as I plug in shore power, and it repeats every 10 seconds or so. This didn’t happen with the lead-acid batteries ever. I could try the lead-acid with the newly installed 8955-AD converter… maybe it’s a converter issue v. a battery issue.

Question 1: if I downgrade converter from 55a to 35a, it will draw less from shore power, but won’t it also OUTPUT less — i.e. 35amp (and possibly avoid tripping breaker)?

I’ve attached an updated battery photo where I’ve marked which wires do what. The RV lines coming from converter/fuse attach to the left battery (RV). The left battery is then piggy-backed to the right battery (B2). The thickest 0AWG lines go to an inverter (I) that I installed and never use. :-)

My wiring does seem different from the diagram shared by billcf7, so then…
Question 2: I don’t have an RV line to both batteries, maybe this is something to change/try?
Click image for larger version

Name:	batteries_text_image_16883969.jpg
Views:	39
Size:	188.3 KB
ID:	94197

I will get into the circuit breaker / fuse when I get home from work later this afternoon to see if it indicates lower amperage etc. I believe the wires from converter to battery are 8AWG.

Thanks all!
blakei is offline   Reply With Quote
Old 06-20-2024, 03:58 PM   #6
Member
 
Join Date: Nov 2021
Location: Kaufman
Posts: 99
I think your wiring is the issue with the different charging rates. Basically you are charging B1 which is then slowly charging B2. When you start drawing from them I suspect it would behave similarly, just in reverse. The suggested method of wiring with the coach POS going to one battery and the coach NEG to the other basically creates the effect of a single, larger capacity battery since the entire current is flowing through both batteries.
__________________

2021 Northpoint 373 BHOK
2022 GMC Sierra 3500 Denali DRW
Rodney27405 is offline   Reply With Quote
Old 06-20-2024, 04:51 PM   #7
Member
 
Join Date: Jun 2020
Location: San Jose
Posts: 56
Quote:
Originally Posted by Rodney27405 View Post
I think your wiring is the issue with the different charging rates. Basically you are charging B1 which is then slowly charging B2. When you start drawing from them I suspect it would behave similarly, just in reverse. The suggested method of wiring with the coach POS going to one battery and the coach NEG to the other basically creates the effect of a single, larger capacity battery since the entire current is flowing through both batteries.

Thanks very much. I'm pretty sure this is how it's been since delivery in 2020, but I may have swapped it at some point mistakenly. I will try this first!


I actually chatted with WFCO tech support, and now I have more things to worry about like voltage drop and distance from the converter etc... but I may try the new converter on lead-acids and the old converter on the Lithiums etc to troubleshoot.
blakei is offline   Reply With Quote
Old 06-21-2024, 01:53 PM   #8
Member
 
GraphiteDriver's Avatar
 
Join Date: Feb 2018
Location: Cincinnati
Posts: 76
I agree with the wiring being wrong. Use the attached drawing from Billcf7 as your guide. That should even out the charge/discharge rates. I also have two batteries wired in parallel and it took a few cycles before they evened out.
GraphiteDriver is offline   Reply With Quote
Old 06-21-2024, 03:00 PM   #9
Member
 
Join Date: Jun 2020
Location: San Jose
Posts: 56
All, thanks for steering me in the right direction. I think I am out of the woods and able to travel!

I rewired per Billcf7, with negative to one battery and positive to the second, and the batteries connected in parallel. I also had some larger gauge wires for the parallel wiring that I used. After making this change, I plugged into shore power and everything worked!!

No more fuse tripping! When I checked the current coming into the batteries with the app, battery 1 was charging at ~22a v 42a in old wiring and battery 2 was charging at ~18a v only a few with old wiring. Everything seems to be fine, and the batteries charged up to 100% after a few hours.

When I opened the lego/fuse cover, there was another red wire that was awkwardly close to one of the leads. I straightened this out... I suppose there was some possibility current was jumping between wires, but I saw no scorching etc.

I will admit it's a mystery to me why the current is ~40amps and the 30a fuse isn't tripping... also strange that when that was going to "one" battery it the fuse would trip, but when going to "both" batteries the fuse is fine.

I did buy one of the suggested clamp meters and used it to confirm ~40a was going from the 30a fuse to the batteries, and more than 30a was on the leads between the batteries.

If I had to guess, I'd say the "30 amp" fuse is closer to 50, and in the "wrong" wiring the battery was spiking over that limit, and somehow with both the draw is more moderated...but this is where my electrical math is poor.

I also connected my truck and made sure it was charging the batteries, and it was at about 3a each. For insurance, I think I'll take the old converter just in case I have to fall back.


Fuse
Click image for larger version

Name:	fuse detail IMG_5159.jpg
Views:	1
Size:	61.0 KB
ID:	94220
Old wiring
Click image for larger version

Name:	fuse old IMG_5156.jpg
Views:	1
Size:	97.3 KB
ID:	94219
Cleaned up wiring
Click image for larger version

Name:	fuse cleand up IMG_5167.jpg
Views:	4
Size:	104.7 KB
ID:	94221
blakei is offline   Reply With Quote
Old 06-27-2024, 04:45 AM   #10
Junior Member
 
Join Date: Jul 2020
Location: Long Island
Posts: 1
Out of curiosity did your rig come with the option to switch to lithium on the charger?
KeithT is offline   Reply With Quote
Old 06-27-2024, 05:01 AM   #11
Senior Member
 
Join Date: Oct 2019
Location: Whitby Ontario
Posts: 598
Most rvs built after 2020 have the option to switch between La and Li and some have auto detection converter/chargers
billcf7 is offline   Reply With Quote
Old 06-27-2024, 09:19 AM   #12
Member
 
Join Date: Jun 2020
Location: San Jose
Posts: 56
Hi KeithT and Billcf7, my 2020 Jayco 28BHS came with the WFCO WF-8955-PEC converter/charger. Per WFCO's website it only charges lead-acid. So I switched to a drop-in replacement WF-8955-AD-MBA which has "active detect" and will charge either lead-acid or lithium and will automatically change charging profiles without any switches. So far so good!
blakei is offline   Reply With Quote
Old 07-06-2024, 11:15 AM   #13
Member
 
Join Date: Jun 2020
Location: San Jose
Posts: 56
Just an update on this after I got back from two weeks of camping. Love the Lithium batteries! I had 5 nights without hookups, generator, or solar and had more than 35% capacity remaining, and a second 3 night stay without hookups, generator, or solar and had more than 60% capacity remaining.

For the dry camping we do, I'm likely to leave behind my generator and suitcase solar panel. Can always charge by truck as needed.

I also had the "trip the breaker" activity again after the 5 night stay when I did hook up to electrical to recharge. It seems to be when the converter is in "bulk charging" mode the batteries draw (?) too much amperage. Once they get to >75% or so, the breaker stops tripping. I will follow up with WFCO about this. In the interim I will either just let it trip, and most likely the batteries won't often be that low.
blakei is offline   Reply With Quote
Old 07-06-2024, 01:26 PM   #14
Senior Member
 
Join Date: Sep 2019
Location: ANYWHERE
Posts: 180
[QUOTE=blakei;1166889]
. . .* All wiring is the same; batteries are in parallel . . .
My wiring does seem different from the diagram shared by billcf7, so then…
Question 2: I don’t have an RV line to both batteries, maybe this is something to change/try?
Attachment 94197

Dude! I almost had a heart attack as soon as I saw your pic. I had to zoom in greatly (CTRL +) to ensure what I was seeing.

Sir please take the advice from that drawing very seriously or the life

of the one batt will be short. This goes for deep cycle and lithium alike. If this were a deep cycle before long you would be able to feel the heat in the battery with your hand and it would spew steam and get hotter and hotter.

As for the charging current draw with those 2 batteries, don't raise a brow about it, you're good. Pls regularly check the connections and keep em clean.
Captain Morgan is offline   Reply With Quote
Old 07-07-2024, 03:19 PM   #15
Member
 
Join Date: Jun 2020
Location: San Jose
Posts: 56
Captain Morgan, thanks for reinforcing the correct wiring. I'm actually going to wire both batteries to a distribution block (one for each cable).
blakei is offline   Reply With Quote
Old 07-07-2024, 03:24 PM   #16
Member
 
Join Date: Jun 2020
Location: San Jose
Posts: 56
Maybe y'all would have an opinion on this too... any problems with me downgrading to the 35 amp converter? The current one is 55 amps, and the batteries will draw 40+ and the fuse trips... if the converter can only provide 35 amps then I don't think the fuse will trip.

To be honest, I'm not sure what all the inverter provides power to; I doubt to something big like the air conditioner, which I think would run off shore power more directly?

The way we camp, I usually plug in to charge the batteries, then we go dry camp and are only running the coach LED lights, fridge control for propane, and the water pump.

What do I need 55 amps for?
blakei is offline   Reply With Quote
Reply

Tags
28bhs, fuse, inverter, lithium

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Featured Campgrounds

Reviews provided by

Powered by vBadvanced CMPS v3.2.3
Disclaimer:

This website is not affiliated with or endorsed by Jayco, Inc. or any of its affiliates. This is an independent, unofficial site.


All times are GMT -6. The time now is 08:21 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright 2002-2016 Social Knowledge, LLC All Rights Reserved.