I had posted earlier about wanting to upgrade my RV batteries and was not sure which battery to use. I made the decision to purchase the Fortune 100Ah LiFePo cells. I bought 16 for a 4S4P pack and a 200A BMS. I already had a Xantrex XC inverter/charger. The pack feeds a junction box through a 250A Blue Sea fuse holder Buss fuse. In the junction box is a bus bar feeding an 80A breaker for the RV leveling jack system and a 60A breaker for the RV utility circuits. The bus bar feeds the inverter through a Blue Sea 2 position 300A disconnect switch mounted on the junction box cover. The first position of the disconnect gives the inverter a soft start through a 10 ohm 25W resistor and the second position bypasses the resistor. The batteries come with covers for the terminals and makes for a clean safe install. I am really impressed with these Fortune batteries.
RV battery upgrade
- Thread starter rfguy
- Start date
The US based vendor refers to it as Simple BMS but there is no brand markings on it other than what may be the model J05W-FH05. I have been charging the pack at 80A for the last hour or so and BMS is cool to the touch. The nice thing about the switch is it can only be turned in the CW direction and is a make before break switch.
Nice use of that tight space! Well done.
Thank you! Unfortunately I did not take pictures of the underside of the switch but it is simple enough to explain. The switch is mounted on a 3/8" aluminum plate on the box cover behind the switch. The ohm value was picked to allow the caps to charge but not with a surge. The highest charge current would be about 1.4A (depending on battery voltage). The highest wattage dissipated if the inverter was turned on in position 1 would be less than 20W. From my tests prior to build the 10 ohm charged quickly that no hesitation is needed in position one. The switch has 2 pairs of contacts. Two labeled 1 and 2. The first position closes the like number pairs, the second position closes all 4. The resistor straddles a #1 contact and #2 contact. Power is fed on the other #1 and inverter fed on the other #2. Pretty simple. I played around with a programmable time delay controller I have but it consumes power. My next step is solar modules and charge controller.