Bigreddogs
New Member
- Joined
- May 20, 2021
- Messages
- 14
Hi guys - Newto the forum here...
Bought a Big Battery OWL170 Ah for my RV. I wanted SOK’s but they were not in stock and my AGM bank was dead - I need two, but only purchased one to start out with because I wasn’t sure Big Battery was a good decision as a supplier. They have some reviews out there that were not positive and those left me with some concerns and a low comfort level.
Here is the situation. I fully charged the battery, installed it in the RV, turned on the inverter a couple of fans, and some lighting until I show 29 amps discharge through the battery via my Victron 500amp shunt and verify that with the reading off the Xantrex inverter.
After researching/educating myself on LifePo4 batteries over the last 2 years I felt comfortable in my decision to buy LFP over AGM for my replacement batteries, and that my Xantrex model RV2012-B20 - 2000Watt inverter/charger would work ok with it - until I purchase a replacement model.
My Xantrex inverter spec shows efficiency is at 94%. I expect that 170Ah battery should provide 30amps per hour for at least 5 hours at 94%. Or 170Ah x .94 = 159.8/30 amps = 5.32 hours of use. So 5 hours minimum I feel is reasonable to allow for resistance in wiring etc.
I check back each hour to see that after 3 hours the battery is shut down. Quick plug into the charger shows the battery is sitting at 10.9V when connected and the BMS comes back online. So I assume the BMS shut it down at low voltage point. Recharge and run the load test again, this time keeping a close eye on system and as the 3 hour mark gets close I go sit and watch the readings in live time. Sure enough, at 91 Ah discharged load the battery is sitting at 10.5V with 28.78 amps draw down (under load) and dropping voltage like a rock. At 9.6V the BMS shuts it down. Looks to me that this battery is under performing.
BB says keep charging and discharging – it will improve as more cycles are completed. WHAT??? Never have I seen a battery improve with use much less improve by 40%. Anyone out there who can advise me on this? I do appreciate any input at this point.
My equipment:
Shunt: Victron Energy SmartShunt 500 amp Battery Monitor (Bluetooth)
Charger: Victron Energy Blue Smart IP22 12-Volt 30 amp 120V, 3 Output Battery Charger NEMA 5-15, Bluetooth
Battery: Big Battery OWL170 12V 170Ah LifePo4
Distance from battery to inverter/charger is approx. 18” to 20”
cable size is 2/0
Bought a Big Battery OWL170 Ah for my RV. I wanted SOK’s but they were not in stock and my AGM bank was dead - I need two, but only purchased one to start out with because I wasn’t sure Big Battery was a good decision as a supplier. They have some reviews out there that were not positive and those left me with some concerns and a low comfort level.
Here is the situation. I fully charged the battery, installed it in the RV, turned on the inverter a couple of fans, and some lighting until I show 29 amps discharge through the battery via my Victron 500amp shunt and verify that with the reading off the Xantrex inverter.
After researching/educating myself on LifePo4 batteries over the last 2 years I felt comfortable in my decision to buy LFP over AGM for my replacement batteries, and that my Xantrex model RV2012-B20 - 2000Watt inverter/charger would work ok with it - until I purchase a replacement model.
My Xantrex inverter spec shows efficiency is at 94%. I expect that 170Ah battery should provide 30amps per hour for at least 5 hours at 94%. Or 170Ah x .94 = 159.8/30 amps = 5.32 hours of use. So 5 hours minimum I feel is reasonable to allow for resistance in wiring etc.
I check back each hour to see that after 3 hours the battery is shut down. Quick plug into the charger shows the battery is sitting at 10.9V when connected and the BMS comes back online. So I assume the BMS shut it down at low voltage point. Recharge and run the load test again, this time keeping a close eye on system and as the 3 hour mark gets close I go sit and watch the readings in live time. Sure enough, at 91 Ah discharged load the battery is sitting at 10.5V with 28.78 amps draw down (under load) and dropping voltage like a rock. At 9.6V the BMS shuts it down. Looks to me that this battery is under performing.
BB says keep charging and discharging – it will improve as more cycles are completed. WHAT??? Never have I seen a battery improve with use much less improve by 40%. Anyone out there who can advise me on this? I do appreciate any input at this point.
My equipment:
Shunt: Victron Energy SmartShunt 500 amp Battery Monitor (Bluetooth)
Charger: Victron Energy Blue Smart IP22 12-Volt 30 amp 120V, 3 Output Battery Charger NEMA 5-15, Bluetooth
Battery: Big Battery OWL170 12V 170Ah LifePo4
Distance from battery to inverter/charger is approx. 18” to 20”
cable size is 2/0
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