Hey @nicklmg, why you don't develop some Lithium Battery like this, but to replace those of UPS?
Something like for this "APC Power Saving Back-UPS Pro 1500VA" (BR1500GI) http://www.apc.com/resource/include/techspec_index.cfm?base_sku=BR1500G
To replace this: Compatible Battery Pack for APC Power Saving Back-UPS Pro 1500 https://www.amazon.com/UPSBatteryCenter-Compatible-Battery-Back-UPS-Warranty/dp/B00ZP7AU12
A LOT of your followers will thank you greatly!
Best regards,
Marco