Heyjimmy911
Let's keep it simple.
Have you ever wondered if you could fit 16 280AH cells, a BMS, a pre-charge a fuse and a heater in a couple pelican cases that you can wheel around? Well, wonder no more. It can be done. Whether or not is should ever be done again..... well probably not. It was a huge pain, getting it all to fit. It was only done because I had some really specific requirements for a solar trailer / home emergency backup. Ghostwriter66 and Will Prowse gave me the idea with their hand truck builds. Batteries are from Jenny Wu at Docan, BMS is from REC and the inverter is from Victron.
It's actually two 24volt packs in series being run by a single 48v BMS.I was initially concerned that cells 8 and or 9 would go out of balance because of the additional resistance of the cable link between the, but it didn't happen. It's been perfect, likely a testament to the quality of the REC BMS and the cells from Jenny.
I bought this BMS directly from Maja at REC but the last couple of BMS kits I just bought a got from Rick at Offgrid software. I guess he is their US supplier. Maja actually gave me a software load that allowed me to use the onboard optocoupler to trigger a heater circuit at temperatures I defined which was so cool of them. I don't know if they will still do that but I'll try for a couple new builds. I used a sold state relay to drive run the silicone heat strips... again something I saw in one of Wills videos.
The cases lay flat and next to each other when they power my solar trailer. They sit upright and next to each other when they are in my garage up against a wall when they are in emergency backup power mode, and I strap them together and hang a multi-plus II on it when I want power where my trailer can't go. The pack is really versatile but took me way to long to build and the cases barley close as there is zero clearance. Also protecting the cells with fiberglass sheets on three sides was also very important thing to do, those sheets took forever to get from China. If anybody has a good, fast source for the fiberglass sheets, please drop me a note or a link if that is allowed.
It's actually two 24volt packs in series being run by a single 48v BMS.I was initially concerned that cells 8 and or 9 would go out of balance because of the additional resistance of the cable link between the, but it didn't happen. It's been perfect, likely a testament to the quality of the REC BMS and the cells from Jenny.
I bought this BMS directly from Maja at REC but the last couple of BMS kits I just bought a got from Rick at Offgrid software. I guess he is their US supplier. Maja actually gave me a software load that allowed me to use the onboard optocoupler to trigger a heater circuit at temperatures I defined which was so cool of them. I don't know if they will still do that but I'll try for a couple new builds. I used a sold state relay to drive run the silicone heat strips... again something I saw in one of Wills videos.
The cases lay flat and next to each other when they power my solar trailer. They sit upright and next to each other when they are in my garage up against a wall when they are in emergency backup power mode, and I strap them together and hang a multi-plus II on it when I want power where my trailer can't go. The pack is really versatile but took me way to long to build and the cases barley close as there is zero clearance. Also protecting the cells with fiberglass sheets on three sides was also very important thing to do, those sheets took forever to get from China. If anybody has a good, fast source for the fiberglass sheets, please drop me a note or a link if that is allowed.
