tybearthegreat
New Member
- Joined
- Oct 28, 2020
- Messages
- 1
Please bear with me because I'm very new to this and learning everything as I go. I will do my best to describe the issue with the utmost clarity and describe my setup to the best of my knowledge.
We purchased a converted bus from the previous owner who did all of the work including installing the entire solar setup.
The original setup:
6x 100-watt Renogy panels(I'm not entirely sure how they are wired)
40a-amp Rover MPPT charge controller
3000-watt Renogy inverter
4x 200ah Renogy AGM batteries(about 2 years old when we bought the bus)
The new setup:
Replaced the Renogy AGM batteries with four USED 138ah Valence LiFePO4 batteries.
The story:
The only thing that is 12v on the bus is the Shurflo 4008 RV water pump that's wired directly into the battery bank. The batteries were wired in parallel with varying cable lengths and gauges. The inverter was wired to the bank with 6AWG cables. We were noticing the life of the batteries was slowly depleting and we knew that would be the case with the number of cycles on them. So, we pulled the trigger on FOUR 138ah Valence LiFePo4 batteries from eBay. I wired them up in parallel and we were seriously impressed with the performance. The batteries didn't drop below 90% for a few days, but those were some nice, sunny days. I'm in the Pacific Northwest by the way. We got a few cloudy days and the batteries began to deplete a little bit more down to about 70%, but that was completely expected due to the weather. The confusing part is that the batteries dropped from 70% down to around 30% in one night and that immediately freaked us out because we JUST spent a couple thousand dollars on these batteries.
I did some research, pulled all of the batteries, charged them individually with my NOCO Genius 10 charger, and all four batteries were resting at about 13.15'ish volts. I wired them back up in parallel with all new 12-inch 6AWG, connected the communications cables on the batteries so they could properly balance, and let them sit for 24 hours or so. The bank was resting solid at 13.15v when I hooked them back up to the inverter with brand new 5-foot 2AWG cables. I removed the larger loads from the system because I wanted to introduce things slowly and see how the system performed. The only loads on the system were the 12v water pump and the lights and outlets the inverter supplies power to via the electrical panel on our bus. The only things we ever plugged in were cell phones to charge, the router/modem that's always running, and the composting toilet fan that's always running. We did NOT plug in our TV, refrigerator, or computers. All of those are currently running off of house power via extension cords.
Again, everything was great and the batteries were generally hanging out around 80-90%. Then we got another run of bad weather and the batteries depleted down to around 70%(12.5'ish volts) today. Then, out of seemingly nowhere, the batteries went from 12.5 to 11.5(30%) in only a couple hours. I've since turned off the inverter via our remoted switch in the bus and the batteries are sitting solid at 11.8 volts. It did the same thing last time as well before I topped the batteries off and swapped out the cables. For the life of me, I can't figure out what is causing the sudden drop of voltage after 12.5'ish volts. The Renogy BT app kind of sucks and there's not a lot of data that I can pull from that to help either.
I apologize for the novel, but I feel like I've tried everything and spoken to everyone I can. Renogy just keeps asking me for voltages of things with more screenshots every time I email them. I get it. The more information they have, the better, but nobody seems to be able to tell me, "Hey! It sounds like it COULD be this, so try doing this!"
While doing research, I've learned that our panels, charge controller, and battery bank aren't sized properly, but could that possibly explain the rapid drop in voltage even with VERY small loads on the system?
I'm open to any and all critique, tips, and whatever else you can throw at me!
Thank you so much for your time!
We purchased a converted bus from the previous owner who did all of the work including installing the entire solar setup.
The original setup:
6x 100-watt Renogy panels(I'm not entirely sure how they are wired)
40a-amp Rover MPPT charge controller
3000-watt Renogy inverter
4x 200ah Renogy AGM batteries(about 2 years old when we bought the bus)
The new setup:
Replaced the Renogy AGM batteries with four USED 138ah Valence LiFePO4 batteries.
The story:
The only thing that is 12v on the bus is the Shurflo 4008 RV water pump that's wired directly into the battery bank. The batteries were wired in parallel with varying cable lengths and gauges. The inverter was wired to the bank with 6AWG cables. We were noticing the life of the batteries was slowly depleting and we knew that would be the case with the number of cycles on them. So, we pulled the trigger on FOUR 138ah Valence LiFePo4 batteries from eBay. I wired them up in parallel and we were seriously impressed with the performance. The batteries didn't drop below 90% for a few days, but those were some nice, sunny days. I'm in the Pacific Northwest by the way. We got a few cloudy days and the batteries began to deplete a little bit more down to about 70%, but that was completely expected due to the weather. The confusing part is that the batteries dropped from 70% down to around 30% in one night and that immediately freaked us out because we JUST spent a couple thousand dollars on these batteries.
I did some research, pulled all of the batteries, charged them individually with my NOCO Genius 10 charger, and all four batteries were resting at about 13.15'ish volts. I wired them back up in parallel with all new 12-inch 6AWG, connected the communications cables on the batteries so they could properly balance, and let them sit for 24 hours or so. The bank was resting solid at 13.15v when I hooked them back up to the inverter with brand new 5-foot 2AWG cables. I removed the larger loads from the system because I wanted to introduce things slowly and see how the system performed. The only loads on the system were the 12v water pump and the lights and outlets the inverter supplies power to via the electrical panel on our bus. The only things we ever plugged in were cell phones to charge, the router/modem that's always running, and the composting toilet fan that's always running. We did NOT plug in our TV, refrigerator, or computers. All of those are currently running off of house power via extension cords.
Again, everything was great and the batteries were generally hanging out around 80-90%. Then we got another run of bad weather and the batteries depleted down to around 70%(12.5'ish volts) today. Then, out of seemingly nowhere, the batteries went from 12.5 to 11.5(30%) in only a couple hours. I've since turned off the inverter via our remoted switch in the bus and the batteries are sitting solid at 11.8 volts. It did the same thing last time as well before I topped the batteries off and swapped out the cables. For the life of me, I can't figure out what is causing the sudden drop of voltage after 12.5'ish volts. The Renogy BT app kind of sucks and there's not a lot of data that I can pull from that to help either.
I apologize for the novel, but I feel like I've tried everything and spoken to everyone I can. Renogy just keeps asking me for voltages of things with more screenshots every time I email them. I get it. The more information they have, the better, but nobody seems to be able to tell me, "Hey! It sounds like it COULD be this, so try doing this!"
While doing research, I've learned that our panels, charge controller, and battery bank aren't sized properly, but could that possibly explain the rapid drop in voltage even with VERY small loads on the system?
I'm open to any and all critique, tips, and whatever else you can throw at me!
Thank you so much for your time!