I have a Pecron model E2000LFP which is a 1920 watt hour solar charger. A Pecron 3,000 watt hour expansion battery is pricy at $699. As an alternative I purchased a 5,000 watt hour 51.2 volt lithium lifepro4 battery at $400. Thus, I have a total of 7,000 watts or 7 kw of storage. I can connect...