Considering getting a 12V inverter for small amounts of emergency power, and I had a few questions. Assume that I will never use the inverter with the Prius off. 1) Will the low-voltage protection on the inverter be adequate to protect the Prius from allowing the battery to go completely dead? The inverter automatically shuts off when the batter is under 10V. 2) Can I safely draw 1250W@120VAC from the 12V system (Inverter claims to be 90% efficient). Can I draw much more safely (I think 1250 is close to the limit)?
1) Draining the battery is not a worry with a running Prius, which you stipulated. 2) You will need to hard wire a power connection for this much power. The power outlets can't come close to supplying this much power without blowing a fuse or melting wires. Tom
Yes - I had assumed that I would need to connect to the 12V battery in the trunk directly. The cig lighter ain't gonna cut it.
You should replace the stock battery with an Optima Yellowtop if you plan on drawing this much power. If the stock battery fades to 10V under load, it may not recover. A 2007 is nearly due for a new battery anyway, and you will be in there already.
bumping this thread, considering the same thing and wondering if I can wire a deep cycle battery in parallel to the stock one for more capacity?
I wouldn't wire a deep-cycle battery in parallel with the Prius 12V battery. The behavior of the high voltage to 12V inverter in the Prius isn't fully known (except by Toyota engineers), so I could forsee the batteries getting a different charge over time or the inverter getting confused. I would just replace the (rather wimpy) Prius battery with something larger if needed. However,with the car on, the Prius inverter can supply around 60A (~80A minus the 20A to run the car's electronics). So you won't tap into the battery really at all unless you pull over 800W. However running a microwave or similar is only going to pull about 1500W, which wouldn't be a major stress on the battery for only a few minutes (and will just quickly recharge after)
I found the voltage fall off occurs in the 75-80A load range, enough to 'low voltage' turn off the inverter. My impression is a stable, 1 kWh is possible but only if attention is paid to wiring. The high currents mean the 12V feed lines have to be done right. As for paralleling a deep discharge battery, I don't have any opinion. My interest was keeping the car in READY and drawing power from the Prius 12V power system. In effect, the Prius as an emergency generator. Bob Wilson
I've used my 2010 in the ready state as a backup generator, but only a for few hours each during two blackouts. Only ran a couple CFL lamps, my internet infrastructure and a high-end laptop. I want to be able to alternately power a sump pump (1/3 HP) and fridge if I lose power during a storm, so I got a larger inverter to handle the startup wattage, then it should be able to handle the steady state.
