CHINS LiFePO4 Battery 12V 20AH Lithium Battery - Built-in 20A BMS, 2000~5000 Cycles, Perfect for Replacing Most of Backup Power, Fish Finder, Fans, Toys, LED Light, Security Camera, Camping etc.

I've had this in my RV for about a year now, and I am impressed with how it powers everything for so long when "off the grid" One trip, we powered our furnace, microwave, lights, water pump, TV and DVD player, and we went 4 days before the capacity had dropped to 50%. We have a DC-DC charger that runs from the RV alternator, and since it can charge at 40A, we can fairly quickly add a good amount of charge if needed, especially when solar is not available. I can easily carry the battery, and have no complaints about its performance. I disconnected the battery over the late fall, winter, and early spring, and still had 95% capacity on the battery monitor! Excellent storage performance.

These are great.I replaced two Interstate lead-acid deep cycle batteries (SRM-27's), and can't believe how much better (and longer) the Minnkota Ulterra functions with these LifePO4 batteries!First, as mentioned I use two of these 12v batteries wired in series to power the 24v Ulterra trolling motor that is mounted on a Carolina Skiff 23UE's bow.The batteries are charged with a Noco GENPRO10X4 12V 4-Bank, 40-Amp On-Board Battery Charger, which allows me to individually select the type of battery for each of the four batteries on the boat to Lead/Acid, Gel, AGM, or Lithium. Obviously, the two CHINS 100AH LifePo4's are set to "Lithium." They needed to be charged upon receipt of the batteries, and I let them charger overnight. No problem.The Ulterra is very sensitive to voltage. Regular Lead and sealed (agm) batteries drop voltage as you use them, causing problems where the Ulterra stops functioning, except at very low speeds. After experiencing many error codes on the Ulterra after an hour or less of use ( if running more than speed 5 (of 10)), I called Minnkota who said, "the Ulterra needs the batteries to have voltage of 12.6v per battery under a load for a combined reading 25.2v total," or it will turn off, as I was experiencing.My multimeter showed that the voltage of the two Interstates (only about 3 months old) was dropping well beneath the 25.2 threshold almost all the time at load -- dropping beneath the 25.2 that Minn Kota wants to 24.6v at speed 5 of 10.To better check and understand and track, I installed a Victron BMV-712 ( https://www.amazon.com/Victron-Energy-MONITOR-VTBMV-S-BMV-712-Battery/dp/B075RTSTKS/ref=sr_1_5?crid=2LK4SOA30P2XT&keywords=Victron%2B712&qid=1650131508&sprefix=victron%2B712%2Caps%2C94&sr=8-5&th=1 ). It confirmed my multimeter readings but allowed more much more detailed tracking. The lead batteries were not maintaining sufficient voltage output. When brand new, they worked better. Likely, I ran them below the 50% charge level a few times without knowing it, and might have damaged them.That's another benefit you'll read about LifePO4's over traditional deep cycle batteries. The lead flavors are not supposed to be run beyond 50% of their rated capacity, so you should only use 44AH of an 88AH battery, or it can be damaged. The LifePO4's can go low. I've taken these to 20% without any problems, and have heard of others going to 10%. Getting them to 20% was a long day of running the trolling motor.The voltage on the two LiFePO4's (in Series) stays in the range of 26.9 to 26.0v under load when operating between Ulterra speeds 1 to 7.5 of 10. It drops into the 25's at speed 8 to 10, but never drops below 25.4, which was at speed 10 with about 50% of the AH's consumed already. Excellent!!These batteries are great!! Strongly recommend for the Ulterra 24V and imagine they would also be great for the 36V Ulterra if you buy three of them. Remember to buy, have, or install a proper lithium battery charger for these, too.One word of caution, I try to avoid running the Ulterra at the high speeds 7.5 or higher for long periods of time (30 minutes) with the LiFePO4's because Minn Kota's website mentioned that the motors were designed with Lead Acid durations in mind, not the much longer durations without voltage drops that we can get from the lithium batteries. Also, the Victron has an alarm that notifies me when the only 15% of the battery capacity remains. Lithium batteries hold their voltage very well until the end, then really, really drop. I'm concerned there would not be sufficient voltage to Stow the Ulterra if I ran it to the end of capacity.

You MUST understand the following when designing your solar power system.Power is measured in watts.Volts times amps equals watts.12 volts times 10 amps equals 120 watts.120 volts times 10 amps equals 1,200 watts.I thought amps were amps, so I designed my system thinking I could run my 10 amp (1,200 watt) microwave for 40 hours with 400 amp hours of battery storage. Wrong. 1,200 watts at 120 volts is 10 amps, but 1,200 watts at 12 volts is 100 amps of continuous power draw from the battery. My system turned out have 1/10th as much power as I thought it would have, but I didn't know that.I have been dealing with power issues since I started living in my van 4 months ago. Every time I ran the microwave for for more than two minutes the batteries would shut themselves off then come back on a few seconds later. It turns out the 200ah 100 amp BMS (Battery Management System) batteries I bought couldn't handle the power draw. I had to replace them with 200ah PLUS batteries with the 200 amp BMS, which allows for 200 amps of continuous power draw.It took me forever to figure out what the problem was. These guys went way out of their way to help me on numerous occasions, including paying for shipping AND packing when returning a battery that turned out to have nothing wrong with it. I bought the batteries after seeing a YouTube video where a guy cut one open and was impressed with the quality construction. The batteries work great and other people I know with Chins batteries have never had any issues with them. The prices are better than most. What really sets this company apart though is the customer service, which is the best I have ever encountered. I have been repeatedly impressed by their responsiveness to my technical questions as I tried to discover what was causing my power problems. So yeah, I highly recommend Chins batteries.UPDATE: July 2023 -- It turned out that all my power problems did not involve the batteries shutting down at all. The power was cut by a circuit breaker which would reset itself after a few seconds. I had no idea self-resetting circuit breakers even existed and assumed that since the lever on the breaker hadn't flipped open the breaker had not tripped. I replaced the breaker anyway just to eliminate the possibility it could be part of the problem, which still persisted.Something to know about nearly all the circuit breakers sold on Amazon and elsewhere: They trip at much lower current draws than they are rated for. My 150 amp breaker was tripping at 100 amps. I replaced it with a 300 amp breaker and that solved the problem that had been defeating me for 9 months.