Can I get help with battery math...batteries-inverter-coffee

wbwood wrote:
Why not just run the generator in the morning and run your keurig then?

Sure, during the day when running a genset is allowed but I sure wouldn't run mine at my usual rise hour of 6am. :R The solution is simple - either make coffee by any alternative method that doesn't require electrical power at all OR ditch the power sucking Keurig and use a simple drip coffee maker that doesn't require anywhere near as much power. For camping we've got a simple 5 cup machine that draws 505 watts over a 6 minute period to make coffee, whether we're running on shore power or my single G27 feeding a 1000 watt PSW inverter. We leave our power sucking Tassimo at home and surprising as it may seem do manage to survive camping without it. :W

Have you ever read The 12 Volt Side of Life?
It may help.

196 A current is too much for your batteries. I don't want to turn this into "50 ways of making coffee" (myself gave up coffee long time ago), but this is the case when you have to sacrifice either Keurig, or the silent way of inverter - and run a generator every single time you run Keurig. Or - double the battery bank.

Here is why:
6.88 AH calculated in other post doesn't include Peuker effect - abrupt increase of AH "actually taken" from the battery at high currents, compared to calculated current*time. Because of this high current, 196A becomes at least 350A of "Peukert corrected current", possibly 400-500A, and can be as high as 1000A for some flooded batteries.

400A*0.05 hr = 20 AH every time. With 225 AH bank you only have 112 AH available. Run your Keurig 5 times and the battery is down to 50%.

This is - if your batteries are still in a good shape and voltage won't drop so low that you won't be able to run Keurig at all.

For best performance you need 4+ batteries. Although I would give it a go. After you make coffee and turn Keurig off check battery voltage after about 5 minutes to see how it recovers. Post the results.

You will not kill your batteries giving it a few tries.

Boil water and get a french press coffee maker. No math involved, no formulas either. Electricity for heating is a very poor use of electrons, and not very efficient.

1400/12V= 167amps X 0.05 hours (3/60= 0.05) equals 5.85 Amp/Hours at 100% efficiency. Inverter at 85% increases the 5.85 to 6.88 AH... BUT 196 amps from your two batteries will probably pull the voltage down to where the inverter shuts off. Anytime you use that many amps (even for 3 minutes) I'd crank the generator or boil water with your propane stove.

That's a 100+ amp draw on the batteries...on each battery. It's not recommended (by me) to use just 2 batteries for such a large load - the voltage drop will be severe, and your inverter may shut down. I recommend 4.

Whether it hurts them over time.. I'm just not sure. Hopefully the thread won't morph into "50 ways to make coffee."

Why not just run the generator in the morning and run your keurig then? That way, you can make coffee and charge batteries at same time. From what I am hearing, people say 100 watt panel per battery. So the keurig may take a good jolt off your batteries and extend the time to get them back up during the day. Go ahead and run that genny in the morning for an hour or so and then let the solar panel catch the rest up. Then you won't need to worry. That's saying you have good sun all day long.