How much battery do I really need, if I've got a 3kW generator?

[Grand Tour]

Originally Posted by pasdad1

For the most useable power in the smallest and lightest package you should get one or two of these....

Don't care about smaller and lighter. I've got the room for conventional batteries, and I've also got the load-carrying (weight) capacity for them.

[Soppy]

I have a small 250 watt sine wave inverter that is used for charging the laptop , drone, camera , etc. I also have a few 12v USB chargers for the phones, Ipads, etc. Most of the places I camp do not have cell or wifi service , so the laptop use is limited.

If you want to use a remote tank for the EU3000 , I'm sure you could install a fuel pump on the engine . You could install a soft start on the A/C that would limit the startup current to around 17 amps , but they are a little pricey , around $400.

[Grand Tour]

I thought the soft start was just a capacitor...

[Harrysait]

GrabdToir, have you seen this Hybrid a/c?
(Do you have a name?)

LEZETi Hybrid Solar PV Powered Mini-Split Ductless Air Conditioner —

Why not look at what Roadtrek has been building for years and copy what you like?

[Soppy]

Originally Posted by Grand Tour

I thought the soft start was just a capacitor...

The soft start is an electronic control module that will limit the incoming current and change the voltage , frequency & current to the motor for starting.
The capacitor is normally referred to as a hard start capacitor and helps if the line voltage is low , but it will not limit the startup current.

[knit]

The loads you describe (frig, phones, laptop, lights but not AC) pretty much match the way we use ours. And we find that 200 Ah of battery at 12v has always worked fine for overnight use and has kept the batteries above 50% state of charge.

We almost always drive some every day for alternator charging and have a 2500w generator for AC and microwave when needed. One thing we also have is 200w of solar. A few times we have gone several nights without alternator or the generator when the solar has enough sunlight. We have 2 6v AGM golf cart batteries. The first set lasted about 4 years. Next time I plan to switch to A single LFP to save a few pounds.

We have a 750w inverter/Charger to both charge the battery when on shore power and to provide 110v to a few circuits.

So in my experience about 200Ah of batteries has worked well when we know that we get significant charging everyday. I do like having a battery monitor to keep track of loads and charge levels. I use a Victron 700 series but the are a number of other brands that would work.

There are lots of RVs with a configuration like this. Ours is a 2013 Roadtrek. You can see electrical diagrams by downloading a 2013 or earlier Sprinter manual from Roadtrek’s support link at their web site.

Good luck on your adventure.