GXMnow
Solar Wizard
- Joined
- Jul 17, 2020
- Messages
- 2,830
The only drawback of using a larger inverter than needed is the cost. There might be a little more power consumed by the inverter at light load, but that difference should be fairly small. A good quality inverter should not be consuming more than about 20 watts when running without a load. When you get to a large low frequency inverter, that might go a little higher, and a cooling fan might pull some as well, but hopefully they use thermal control, so the fan only runs when the unit is getting warm. My cheapo runs the fan all the time, I may put in a thermal switch some day, but it really is just an emergency use unit.
Many years ago, I had a jump starter box with a 17 ah AGM battery. I ended up screwing a 300 watt inverter on the back, and used that thing to run all kinds of stuff for years. About 5 years after I built that, they finally started selling unit like that. Maybe I should have patented my idea back in 1990. When the AMG batter died, it was cheaper to get a whole new jump starter box. And the battery in the new one died in only 2 years. I think I will stuff it full of LFP cells. 4S7P of the 6,000 mah ones they have at Battery Hookup looks like they will fit and push the capacity from 17 AH to 42 AH. The surge current goes to 252 amps. That should start any car I have. And I will change out my ancient 300W modified sine inverter for a 1,000 watt true sine wave one. This is a whole lot smaller scale than you are talking about, but it sure is convenient to have a one hand carry-able power station. Since the AGM battery failed, I have missed having it on hand. Even with my battery backup inverter in the house, I still used that thing often.
Many years ago, I had a jump starter box with a 17 ah AGM battery. I ended up screwing a 300 watt inverter on the back, and used that thing to run all kinds of stuff for years. About 5 years after I built that, they finally started selling unit like that. Maybe I should have patented my idea back in 1990. When the AMG batter died, it was cheaper to get a whole new jump starter box. And the battery in the new one died in only 2 years. I think I will stuff it full of LFP cells. 4S7P of the 6,000 mah ones they have at Battery Hookup looks like they will fit and push the capacity from 17 AH to 42 AH. The surge current goes to 252 amps. That should start any car I have. And I will change out my ancient 300W modified sine inverter for a 1,000 watt true sine wave one. This is a whole lot smaller scale than you are talking about, but it sure is convenient to have a one hand carry-able power station. Since the AGM battery failed, I have missed having it on hand. Even with my battery backup inverter in the house, I still used that thing often.