In a departure from his usual repair and tear down fare, [Kerry Wong] has set out on a long-term project — building a whole-house battery bank. From the first look at the project, this will be one to watch.
To be fair, [Kerry] gave us a tease at this project a few months back with his DIY spot welder for battery tabs. Since then, he appears to have made a few crucial design decisions, not least of which is battery chemistry. Most battery banks designed for an inverter with enough power to run household appliances rely on lead-acid batteries, although lithium-ion has certainly made some inroads. [Kerry] is looking to run a fairly small 1000-watt inverter, and his analysis led him to lithium-iron cells. The video below shows what happens when an eBay pack of 80 32650 LiFePo4 cells meets his spot welder. But then the problem becomes one of sourcing a battery management system that’s up to the charge and discharge specs of his 4s battery pack. We won’t spoil the surprise for you, but suffice it to say that [Kerry] really lucked out that only minimal modifications were needed for his $9 off-the-shelf BMS module.
We’re looking forward to seeing where this build goes, not least because we’d like to build something similar too. For a more traditional AGM-based battery bank, check out this nicely-engineered solar-charged system.