Home battery glossary
The terms a salesperson uses to make a quote sound better than it is, defined in plain language. We lead with the part that actually changes your decision, and we say when it does not matter.
Depth of discharge (DoD): why usable capacity is not rated capacity
Depth of discharge is how much of a battery you can actually use. Usable kWh equals rated kWh times DoD, and on older or NMC packs that gap quietly cuts your real backup hours.
kWh vs kW: capacity vs power, explained
kWh is how much energy a battery stores. kW is how much it can deliver at once. Mixing them up is the single most common home-battery mistake, and it changes how many backup hours you actually get.
LFP vs NMC battery chemistry (and what LiFePO4 means)
Almost every 2026 home battery uses LFP (lithium iron phosphate). Here is why that chemistry beats NMC for a fixed home install, and what the LiFePO4 label on the spec sheet actually tells you.
Time-of-use (TOU) rates: why a battery is worthless on the wrong plan
Time-of-use plans price electricity by the hour, with expensive evening peaks. A battery profits by charging cheap and discharging at peak. On a flat-rate plan with no spread, that same battery barely dents your bill.
Virtual power plants (VPP): getting paid to share your battery
A VPP pays you to let your utility tap your home battery during grid stress. In California, programs can pay roughly $400 to $1,500 a year, which can meaningfully shorten payback. The catch is that availability and pay vary by utility.