Camper Battery
Overview
The camper originally was designed to accommodate up to three Fullriver HGL120-12 batteries. Since the objective here was to power a 230V induction cooktop and various accessories, with loads up to 3000VA, a lithium battery as large as would fit in the space available was a necessity.
TT30's EV-Power lithium 12V 120Ah batteries . CLICK for close-up.
At the time of construction lithium batteries with the necessary management hardware were very much more expensive than now. I designed and installed a LiFeYPO4 battery using 16 x 90Ah prismatic cells and a purpose-designed battery management system (BMS). This worked very well for eight years but then one of a group of 4 cells lost substantial capacity. I have replaced the whole battery and BMS with 3 x 120Ah LiFePO4 drop-in batteries from EV Power. These give the same performance as the earlier battery but with internal BMS and Bluetooth monitoring.
Advantages of the installed LiFePO4 batteries are
(i) the Iron Phosphate type
of lithium cell is very stable and safe, (ii) is very resistant to thermal runaway so does
not burn nor fuel a fire, (iii) does not vent noxious gases when being charged, (iv) is very
resistant to vibration, and (v) is less than half the weight and much better performance
than lead-acid types.
The EV-Power manual for the drop-in batteries gives the care and charging instructions. A mobile phone app "EVPOWER 1.0" allows monitoring of each of the three batteries on the phone.
The three lithium 12V 120Ah batteries installed in their box above the spare wheel.
The opening screen of the app lists the three batteries from the left. Note the strength of the Bluetooth signal is weak because the batteries are in a steel box.
Touch any one of the three listed to see current performance.
The three batteries are wired in parallel using four Matson 20cm copper braded engine ground straps to form what is called "the camper battery" in other pages of this Web site.
Just how the battery is wired into Scrubmaster TT30 is described on page 12V power.
State of Charge of the selected battery.
Selected battery voltage and current discharge.
Voltages of the four groups of cells in the selected battery.
Battery Management
The battery is charged from the solar panels or from the vehicle alternator or from the 230V mains charger
If the state of charge of the battery drops so low that the BMS turns off the battery and it appears to be flat, only alternator charging using the DC-DC charger or the 230V mains charger will be able to bring the battery out of "sleep" mode and then charge the battery. See EV-Power manual for a discussion of this.
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