Lot of changes since the last update. I decided to move the solar equipment into another rack. The rack that has my amplifier project on it had a bunch of gear that was not being used. So I’ve mounted the MPPTs and the Pi on the front. In the bottom of the cabinet there are 4 100Ah batteries set up as 2S2P for 200Ah at 24V. The third pair can easily be integrated back in. The WZRLEB inverter is in the back as well as the 24-12V Victron converter.
The existing rack will now be a big battery station. I’m going to try to build it in a modular fashion. There is now 2 200Ah 24V batteries in the bottom using 2 JK BMSes. The middle of the rack is still used for building new batteries and the top currently is the third set of 100Ah batteries as mentioned earlier.
The goal is to have 800Ah @ 24V of these blue cells in the bottom. The HP power supply will stay to charge banks if necessary. Not sure what the top shelf will contain yet but it’s great to have options.
The JK B2A8S20P is a great BMS. I now have 2 of them hooked into the Victron system via RS485. I used two add ons to VenusOS, the first dbus-serialbattery and the second BatteryAggregator. The first bank comes in via my SmartShunt. Bank 2 & 3 are the JK BMSes via dbus-serialbattery. They are all added together with BatteryAggregator.
This works great! The only thing I may change is to add another SmartShunt in front of all the batteries rather than use the aggregator.
I decided to run the batteries in a 2P8S configuration. That allows me to use 16 batteries at 200Ah. The BMS will only report 8 cells but I haven’t seen that as an issue. I don’t think I’d go to 3 or 4 cells paralleled but 2 seems to be fine.
There will be more to come in this saga as I add the second shelf with another 32 cells. I will likely switch to the JK PB2A16S20P BMS for the last two banks. This BMS will do 24 or 48V and has built in CAN bus as well as RS485 networking. This way if I decide to go to 48V I can just combine all the cells on a shelf to a 2P16S configuration and have 200Ah 48V. I can then repurpose the two B2A8S20Ps for either 24 or even 12V batteries. My end goal is to have a whole house system at 48V. By planning ahead with choices in MPPTs, BMSes, etc. it will save a lot of money down the road.