Simplest dual-battery & 2000W inverter setup

Hey guys,

Need some thoughts from guys who have dual battery / big inverter setups installed in their trucks.

Here is the use case: I want to be able to run a Keurig or a small microwave while overlanding, for short periods, powered by the truck.

Here is the solution we are thinking of:
- Add an identical second battery in parallel to the stock battery. We are thinking we need a second battery since a Keurig or small microwave will likely pull a lot of amps at startup, and so a single battery will not have enough juice for startup even with truck running.
- Run zero gauge wiring from it to bed, and install a 2000W inverter in the bed.

Pros to this setup:
- Easy to install,
- Relatively inexpensive option as it has no switches or solenoids.

Cons:
- Yes, there is no run-down protection and stock battery is at risk of getting drained and truck may not start if the accessories we are running off the second battery are left on for long periods. I don't plan on running a fridge or leaving any accessories connected, I only need the inverter to work while truck is running.

Questions:
- Stock alternator is beefy enough to keep two batteries charged, correct? I am not concerned about how long it takes to charge as I won't be drawing any power from the second battery while stationary.
- Will wiring in a second battery in line with the stock battery confuse the electrical system in any way, and throw codes etc. ?

What do you guys think? Interested in thoughts from folks with personal experience with dual battery setups.

No dual battery experience with the Raptor yet. My advice, you should be able to isolate the batteries. A switch like this https://www.westmarine.com/buy/perk...1-all-2-battery-switch--14996433?recordNum=10 is cheap and easy insurance that you won't be stranded with a dead battery. Personally I would not take an electric coffee maker or microwave overland.

What do you guys think

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I think there are going to be many ensuing starbucks posts, that’s what I think.

Although I would like to entertain the thought of a bigger inverter, I’m not yet into “overlanding”. I think the 2nd battery will add a lot of weight that you could possibly avoid or workaround.

something wrong with a good thermos? Not joking here, I’ve had my Nissan(?) thermos keep coffee warm more than 24 hours - and by warm I mean hot enough to drink and this was in the winter, used it at the range, etc..

Ok, I won’t wait for the gen1 starbucks gurus.
With your Raptor and a thermos, just stop by any starbucks, hand over your thermos and get a fill up of house blend black and move out sharply.

The ‘wave to cook with. well, IMO, that’s why God invented fire. for the same weight payload you can have a portable propane stove and camp cookware.

Guys, not interested in anyone's critique of my overlanding philosophy or suggestions on thermos (sorry smurf).

Interested in your feedback on the approach I outlined for my dual battery / inverter setup. Can we keep it to just that please? Seems next to impossible to get constructive feedback on specific questions on FRF without every thread turning into an unrelated circle jerk.

My first thought - are you overthinking it? I think my small Keuring in my RV pulls 1500 watts. Can't you run that off of one battery/inverter? Sure, you wouldn't want to run it for long, but shouldn't it work? I'd try it.

I've run a dual battery system in two jeeps (but not my Raptor) and my best advice mirrors some of that above. Make sure you can isolate them or when one dies you don't know it and eventually end up with two dead batteries. It makes me ponder setting up a system where one battery is charging from the vehicle only, but not powering it unless you engage it (use this battery for accessories such as your Keurig).

As long as you are wiring in parallel (not series) your electrical system shouldn't care.

Also, on a side note, make sure your second battery tray is really mounted beefy or it will fall out in the sand dunes and your friend will run it over. Ask me how I know...

That's when I found out my other battery was dead.

They make automatic battery isolators for exactly what you're trying to do. No need to run the risk of draining your starting battery.

ReefBlue said:

They make automatic battery isolators for exactly what you're trying to do. No need to run the risk of draining your starting battery.

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Quick search on Amazon and you're totally right!! Perfect and easy! My previous setups had a switch, Batt A, Batt B, or both, but it wasn't smart like this. I like it. I'd really like to find one that let's you manually engage the second battery like a jump start if needed. I'm sure there probably is something.

I've posted about this before on FRF because it's a great idea for a number of reasons.

Dual batteries are great and there are many ways and products to use to do it right. Of course you'll want to isolate the main battery from the house battery so if/when the main battery goes down you'll have a backup (house) battery while being able to charge them both.

My question to you is - where are you going to put the house (2nd) battery to ensure it's securely installed?


Here's a great thread on making your own battery isolator with lots of related information: How to make a cheap isolated dual-battery setup for $50 - Expedition Portal



Blue Sea Systems makes great products - here's theirs:
http://assets.bluesea.com/files/resources/brochures/980006440.pdf

Thanks for the suggestions guys, appreciate it.

I am not really concerned about draining my starter battery, for my use case, I don't quite see the need for a battery isolator. Here's why: I don't have lights, fridge, or any other accessories that will make a standing draw on the battery. All I want is enough cold cranking amps to get a 1500w-2000w appliance going till the inverter is able to support it on its own for 5 minutes or less.

I understand that a 2000w inverter provides much less than 2000w at start (peak) and provides about 1500-1700 continuous. Is that correct? Hence the need for a second battery to get the Keurig started.

So, even if I isolate the house battery, I would still need to flip the switch to have both batteries working to use my appliance, rendering the battery isolator redundant in my case.

Besides, I am not that worried about having a dead starter battery. I carry an anti-gravity AG-XP-10 portable battery jump start box in the car at all times (plugged in and charging all the time too) and it will not be a big deal to jump start in the worst case.

So... back to the original scenario of just wiring in a second battery in parallel to the car battery and running zero gauge wiring to a 2000w inverter - other than the risk of draining the starter battery (which I fully acknowledge), any other downsides to that setup?

Get a glow plug relay out of an early model goat. Looks like a solenoid but rated for 80 or 100 amp continuous.