Electrical Help pls
Hi! I bought a 250 Watt Electric Heater to stave off the chill at night (the tag says it uses 2.1A). We have solar panels to charge our 200A battery (I don't think that matters, but just in case). ...
Forum Discussion
maria_bettina wrote:time2roll wrote:
Inverter should draw power direct from the battery using #8 wire minimum. 250w is close to 25 amps at 12 volts.
If I bought a new inverter and connected it to the battery directly, I am still looking at 25A. Which is crazy. We have a 200Ah battery, so 4 hours of continual use (before I reach 50% battery charge)? But if that same 250 Watt heater was DC, that's a whole different story. Electricity is like magic. Totally boggles my mind! Haha
Watts are watts.
Divide by the voltage to get the amps.
DC can feed the heater directly or it can feed the inverter...of course the inverter isn't 100% efficient so it will use even more amps.
As previously mentioned, 250w is going to be upwards of 20-25amps depending on the exact voltage of the battery bank.
Heating takes a lot of power, even with a small heater. There's a reason, most RVs go with a propane furnace and only power the fan with electricity.
Heavy power demands (lots of watts) are typically done with 120v AC, with the exception of starter motors but they have huge cables and only run for a few seconds to compensate. At 10 times the voltage 120v AC, amperage is drastically lower. When powering an inverter, you want big thick cables from battery to inverter and you want them as short as possible because it's going to be a lot of 12v DC amps.
