Myself if I needed some lithium I would be very tempted by the sinopoly, You get double the ah for less then 1 battleborn. I been using lifepo4 almost 2 years (220 ah ) and wouldnt go back to lead acid. I checked some youtube videos on the sinopoly, I notice they mention that they go out of balance. I notice that also on my lifepo4 and it wouldn't be a deal breaker for me. As long as the voltage is good and a cell doesnt drain by itself it will work.
If you buy them 2 things I recommend is a 4s active balancer (about 100 dollars) , this will keep the battery in balance 24/7 when charging/discharging, and a coulombmeter ( DROK LCD Digital Multimeter Charge-Discharge Battery Coulometer Tester ) you can find on amazon for 30 dollars. As far as bms, I'm using a 4s 30 amp model cost me 4 dollars. Yes a 4 dollar bms on my 220 ah lifepo4, but you can spend more if you need a higher amp output. I rely on the active balancers to keep it in balance, the bms is just for low/high voltage control.
I would research more but I would definitely hold off buying lead acid if lifepo4 is available at decent price. Electricarpartscompany where I bought my active balancers sells 200ah lifepo4 for 255 dollars but has shipping costs, thats not much more then the sinopoly, buts its also chinese lifepo4. As far as safety as long as you don't punch a hole in them they are safe. You can use an overvoltage relay like I do as a deadman switch to prevent overcharging in case bms fails.
At first I was concern about the weight at 12.78 pounds, it seem light to me, but I checked the weight with other 200 ah and its about the same.
a 4 cell 200ah lifepo4 for 52 pounds, comparable lead acid would be about 140 pounds. My 220 ah made of 160x cylindrical cells weighs about 64 pounds. Lifepo4 doesnt require as much attention as lead acid, you don't have to fully charge them, you don't have to trickle charge them. Just check the voltage from time to time if you are storing them. And I charge with my 240 watt solar panel 20 amp ecoworthy mppt (non-lithium capable), as long as you can adjust the bulk voltage any solar controller will work.
I copy the specs from the website
Product model: SP-LFP-200AHA
Nominal capacity: 200Ah
Nominal voltage: 3.2V
Weight: 5.8kg 12.78 lb
AC impedance: ≤0.4mΩ
Cycle life: ≥2000 times, 80%DOD, capacity retention≥80%
Self-discharge rate: ≤5%
Dimension: 280*180*69mm
Standard charge/discharge current: 67A
Max.charge current: 1C(200A)
Charge cut-off voltage: 3.65V
Max.continuous discharge current: 3C(600A)
Discharge cut-off voltage: 2.5V
Operation temp.: Charge at 0℃-45℃, discharge at -20℃-45℃
Storage: -10℃-45℃
cost- 203 per battery and free shipping.
active balancers
