RV FEATURE
LITHIUM BATTERIES ’ INTERNAL BMS
We ’ ve mentioned before that lithium iron phosphate ( LiFePO ) batteries have revolutionised the off-grid camper scene , opening up almost limitless possibilities for free-camping .
What you may not know is that these batteries feature an internal battery management system , but it is a vastly different beast to what you will find inside a modern caravan , although they do share some similarities .
Without going into a lot of technical detail , LiFePO batteries require some electronics to balance their internal cells or keep them at the same voltage . You can see this at work by using their Bluetooth connection and smart device app . For 12V batteries , they have four individual cells each rated at around 3.2 volts ( 3.2x4 = 12.8 ). The internal BMS monitors the voltage of the individual cells and directs charging to ensure they keep at relatively close voltages to each other .
These internal systems handle many other aspects of the battery ’ s operation . They monitor amps in and out , battery status , battery voltage , battery temperature , cycle count and rated capacity . They have a number of protection systems , including extreme temperature cut-outs and deep discharge protection . Some of the higher-end batteries may even tell you the time remaining to discharge or recharge , and a history of any recent errors detected by the BMS .
Almost all of them will provide an indication of SOC , although this can be inaccurate with certain configurations . Combine these features with a quality power management system and you have all the tools you need to camp for extended periods offgrid with confidence .
The Victron SmartShunt is the cheapest and easiest way to add advanced battery management to an existing electrical system .
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