[Low Temp Cut-Off Protection &10-Year Product Support] Low temperature cut-off protection can maintain a healthy battery lifetime. When the temp reaches 23℉~41℉, this lithium battery will stop being charged, and when the temp reaches -13℉~5℉, the battery will stop discharging. Moreover, Dr.Prepare battery offers every customer 10-YEAR product support. If you have any question, please feel free to contact us. Dr.Prepare team will provide professional knowledge and service to solve your problem! [Series and Parallel Connection] With 4 pack of 12V 100Ah LiFePO4 Battery, whether creating 48V 100Ah lithium ion battery bank or a 12V 400Ah power system, our Dr.Prepare LiFePO4 batteries are both supported. You can even wire up to 16 batteries in series and parallel to build a powerful home battery bank system with a power of 20.48 kWh. [3,000 Lifespan, 10-Year Lifetime] At 80% deep discharge the LiFePO4 has 3,000 cycles, providing about a 10-year lifetime of daily use, while the sealed lead-acid batteries have only 500 cycles. 4 pack of 12V LiFePO4 batteries provide a maximum of 5120Wh power output, which is 2 to 3 times more powerful than SLA batteries of the same size. Continuous discharge current can power most electrical devices, such as fish finders, solar power, electric chair wheel, camping, home alarm system, scooters. [Grade A+ LiFePO4 Cells & Smart BMS Protection] The advanced Grade A+ cells inside are UL tested, ensuring a 10-year lifespan and over 5,000 cycles. Built-in premium 100A BMS, there are 6 layers of safety protection for increased performance and longer lifetime, including low temperature, high temperature, over-charge, over-discharge, over-current, and short circuit protection. [Warm Tips] Our 12V 100Ah LiFePO4 battery is suitable for energy storage battery rather than car batteries, starting batteries or golf cart batteries. As for the trolling motor, 2 batteries are for 12V 62-86lbs thrust trolling motor, 4 batteries provide 5120Wh power output, able to last longer runtime or support greater thrust. A 60A CIRCUIT BREAKER (not included) must be used to protect your battery. [About Recharging] 12V (14.6V) 5A/10A/20A/50A Lithium battery charger reqiured or solar panel to recharge our 12V 100Ah LiFePO4 Battery. A solar charge controller is needed when using a solar panel for recharging, and lead acid battery charger CAN'T recharge our LiFePO4 Battery. Each battery must be fully charged separately with a 12V lithium charger before in series, so that each battery in series will achieve the balance effect and not deliver too much voltage to the remaining batteries. Built-in low and high temperature protection, our Dr.Prepare 12V lithium batteries provide superior safety usage for your solar system. Supports connecting 4 batteries in series to create a 48V battery bank or in parallel to build an expanded 400Ah battery bank system. 3,000 life cycles ensure a 10-year lifetime, and our LiFePO4 batteries are all backed by a leading 10-year product support. The built-in LED screen offers real-time power capacity monitoring, no more guesswork. Choose our more reliable lithium iron phosphate batteries for your family RV trips, off-grid cabins, marine vehicles, solar energy storage, or lead-acid replacement. Important Notes: 1. Make sure to tightly screw the battery terminals in, as having loose battery terminals will cause the terminals to build up heat resulting in damage to the battery.