Amp hours used: 1,200 watt electric kettle, on for 3 minutes?

[Steve_382]

Good explanation Wowbagger. The important difference between 12v systems and 120v systems is the current draw that requires much larger cable sizes. 1200w is 10 amps on 120v and 100 amps on 12v. A #14 wire is OK for 10 amps. As you might expect, 100 amps requires a cable 10 times as large roughly.

[Vanimal]

I'm confused what ever happened to just plugging it into your generator? It will do all the calculating for you, that is why it is called a generator!https://www.google.com/imgres?imgurl...MygDegUIARCxAg

[kevman]

The timing of this thread is great! We just finished a 1 week winter trip and pushed the battery pretty hard (relative to the summer where the Solar actually does something). How low is too low under a heavy inverter load? I got freaked out running the toaster and seeing ~11.5 or even lower on the battery monitor. I mean I could not use the toaster or coffee machine but what fun is that!? I ended up idling to take the edge off but did I actually need to if my batteries still had a decent charge remaining?

[LosAngeles]

Originally Posted by kevman

The timing of this thread is great! We just finished a 1 week winter trip and pushed the battery pretty hard (relative to the summer where the Solar actually does something). How low is too low under a heavy inverter load? I got freaked out running the toaster and seeing ~11.5 or even lower on the battery monitor. I mean I could not use the toaster or coffee machine but what fun is that!? I ended up idling to take the edge off but did I actually need to if my batteries still had a decent charge remaining?

What kind of batteries are you using? Flooded? AGM? Lithium?

[Wowbagger]

11.5V under heavy load is OK. For lead chemistries - AGM, SLA, FLA, Gelled minimum is about 11V. LiFePO4 minimum cell voltage is about 2.5V, so 10V (and that's fully discharged).


But if you are routinely seeing that when you run a significant load on the inverter, either a) your batteries aren't being charged, b) your batteries are at end of life, or c) you have too little battery for the load. If you are running a 1200W toaster, that's about 110A at 12V (with inverter inefficiencies), so you want to have about 220Ah of lead or at a bare minimum 110A of lithium. The various deep-cycle lead chemistries really don't like supplying more than a 0.5C rate for any length of time (in other words, they don't like being discharged in less than 2 hours - "C" rate is 1 hour discharge). Bare LiFePO4 can do up to 3C rate (20 minute discharge), but integrated systems like BattleBorn may have limits due to the built-in BMS circuits. And it is still better to keep the discharge rate below 1C even for Lithium.

[kevman]

Thanks.

It's a 235Ah AGM battery. When I saw that voltage I was probably at 75% (60Ah discharged already) or less and was running a 900W toaster. It's also winter so while the battery is inside the "heated" space it was probably close to 5°C (40°F) at the time which I believe also as an affect.

[Angel]

Ever heard of cold brew????? Hee Hee