Hello. After reading a number of posts online and in this forum, when my original battery started to die on my 2015 320cs, I decided to switch to a Chins 100w Lithium. From what I had read it should be a clean swap sans the fact that the older converter wouldn’t charge to a full 100%, which I was fine with (it charges to around 90-95% though).
Also have folding solar panels to help top off.
I moved the battery location to inside under the bench with the rest of the electrical. Just ran 10g wires from the tub, under the trailer and up into the bench so wiring should be correct.
Having an issue where the battery does fine and will remain charged for days or weeks, but then suddenly drops all charge to zero (like over the course of an hr or two). I’ve tried all sorts of tests, and installed a battery cutoff and seems to be fine when I disconnect the battery from the rest of the system.
Any thoughts on what to check?
part 2: finally decided to just take it into a local RV service place and they said it needs a new converter to fix this issue. I’m skeptical that that will solve it. They also quoted me nearly $900. I know the part is around $270. That just seems high to me. Anyone know if the swap would require that much labor time? And is it something I could just swap myself with the new part? I’m pretty handy with most things and have a general understanding of wiring.
Thanks in advance!
Comments
My suspicion is that something is amiss with the BMS in your battery. Are you certain that there is nothing connected that is drawing down the battery?
Ken / 2023 Tab 400 “La Bolita” (20,000+ miles) / 2024 Toyota Sequoia
2024 - 2 Trips - 25 nights - 4 National Parks, 3 National Forests
One quirk with LiFePo is that they like to see a higher charging voltage. The higher voltage allows the BMS to balance the cells. That's why there are specific chargers, but you don't necessarily need a new converter. You can also use a LiFePo capable external charger, or the solar panels if the controller has a LiFePo setting. Personally I use the standard converter for bulk charging and then solar for the last few Ah.
Your battery needs to be brought up to a full charge with 14.4 -14.6 volts bulk and allowed to rebalance with an absorption at ~13.6-13.8 volts for at least a couple hours. My Li batteries would not fully charge until I raised the Victron default Li charge bulk setting from 14.2 to 14.4.
IMO - Until the battery is properly fully charged with lithium specific charger it will be very hard to diagnose the root cause of your battery problems.
If you can handle the battery rewire the converter swap should be manageable. The AC breakers are difficult just because of many stiff solid core 12awg wires in a small space. Label the wires color (DC) or breaker number (AC) and they should match up. You'll have to put the proper fuses in the DC circuits...
Have fun?
Bob
2023 Ford Maverick XLT
The Finger Lakes of New York
Ken / 2023 Tab 400 “La Bolita” (20,000+ miles) / 2024 Toyota Sequoia
2024 - 2 Trips - 25 nights - 4 National Parks, 3 National Forests
This is the one that I purchased. It comes with M8 eyelets that you can connect to your battery. I used battery bank because I had two 100ah batteries connected together.
Ken / 2023 Tab 400 “La Bolita” (20,000+ miles) / 2024 Toyota Sequoia
2024 - 2 Trips - 25 nights - 4 National Parks, 3 National Forests
The converter does not have an on/off switch. A common approach to create one is to split the last branch #5, from a single circuit breaker into a tandem 2 circuit breaker. The OEM converter/charger is usually wired into branch #1 (on a newer 320). You bring that AC wire over to one of the circuits on the tandem breaker. You are then able to turn off the charger/converter with the breaker ON/OFF switch.
2021 Jeep Grand Cherokee
Southern Maryland
Ken / 2023 Tab 400 “La Bolita” (20,000+ miles) / 2024 Toyota Sequoia
2024 - 2 Trips - 25 nights - 4 National Parks, 3 National Forests
2018 Nissan Titan Pro 4X "Big Bird"
Leadville Colorado
In my case, I have an inverter with a transfer switch that puts AC power to everything in the trailer when on battery power. When the inverter is on, if there is not a way to turn off the charger, you end up in a loop where battery power is now powering the battery charger and charging itself, the battery (if that makes sense). To avoid this condition, you need a means to turn off the charger. I actually did not do as I suggested above, but wired my charger into the transfer switch so its only powered when on shore power via a relay in the transfer switch.
I have a different experience with my non lithium WFCO charger than most. I find when on shore power, the charger rarely kicks on and sends any current to the batteries to charge them. I can fanagle it on by turning turning the main breaker on /off, when it does begin to charge, it will fully charge my batteries consistently to 100% but extremely slow. I have gone to a stand alone Victron charger, but did not disconnect my WFCO charger.
2021 Jeep Grand Cherokee
Southern Maryland
Ken / 2023 Tab 400 “La Bolita” (20,000+ miles) / 2024 Toyota Sequoia
2024 - 2 Trips - 25 nights - 4 National Parks, 3 National Forests
I then, again, charged it back to 100% with the Victron Li charger, but noticed the BMS showed 100% long before the Victron completed its bulk cycle etc.
So, at this point, I believe the issue is indeed, as many stated above, that the BMS is "out of whack" and that the battery wasn't suddenly discharging from 64% to 0% (for example) as I thought, but rather was probably never fully charged and was probably actually only 15% (or something) charged when the BMS showed 64%, and the battery just ran out, giving the appearance of a sudden drop from 64% to 0%.
Anyway, still doing some further testing and anxious to try it on the next trip, but feeling pretty confident that was/is the issue. Thanks a ton to all who weighed in on my issue, and glad I didn't pay $900 for a new converter which clearly would not have fixed the issue.
Last question: could I now just install the Victron Li charger under the bench near the LiFePo battery, screw down the pos-neg leads to the battery, and then just plug the cord into an empty AC electrical socket (a 2 gang outlet that it appears the water heater is plugged into) there? I'm thinking with this, when we plug into shore power, it will fire up the Victron to "top off" the battery. OR, will this conflict with the converter at all or cause some dangerous electrical feedback loop or conflict? Thanks.
2023 Ford Maverick XLT
The Finger Lakes of New York
2020 nuCamp T@B 320S * Jeep Wrangler
What is reason to turn off the solar and/or batteries when using the IP22?
Thank you
2021 Jeep Grand Cherokee
Southern Maryland
2020 nuCamp T@B 320S * Jeep Wrangler