2020 Honda Pilot - second battery questions

[MechEngnr68]

My wife and I just purchased a 2020 Honda Pilot EX-L. We don't do much "real" overlanding, other than maybe exploring local fire roads and such, plus we stealth camp in the back of our vehicle, so this AWD Pilot is perfectly adequate for our needs. Since I use a CPAP at night, I was pretty stoked to find that this trim level of the Pilot has a rear accessory power port that I can use to run my CPAP. However, last weekend we found that the rear accessory power port is a switched power port, and the Pilot's onboard computer will only allow it to remain in accessory mode (it uses a push-button start, and RFID rather than an actual ignition switch) for about 2 hours before shutting everything down, including my CPAP - waking up every two hours or so in order to sit up, crawl forward, and hit the start button again to put the car back into accessory mode is not conducive to a good night's rest. Therefore I'm looking for some advice on installing a second battery to run my CPAP, and maybe some low-voltage LED lighting while camping.

From previous experience, I've found that a 100amp deep-cycle marine battery will run my CPAP without recharging for 4-5 nights, or about 40-ish hours. However, when stealth camping, we typically only spend one night in a location, so the second battery doesn't need to be that large.

So, I'm looking for recommendations on a smaller-sized battery, or batteries, where to mount them so they're hidden, and the best way to connect them to the vehicle's charging system as I believe the pilot has a smart charging system, so the standard isolation relay likely won't work.

Thanks,
Dennis

 

[Boostpowered]

Is this an electric vehicle? That is the only info I can find about smart charge, you will likely need to get with someone at Honda to find out if you can run secondary battery. Ev or normal if it has some proprietary way of charging it will likely either no be doable or take a special isolator.

Does a battery for you cpap not hold a charge for the drive out? If driving during the day and you just want it topped off use a solar panel to trickle charge it that would be the easiest and likely cheapest way.
In regard to hiding the battery look for somewhere under the hood to put a tray to hold one, depending on the room under the hood you may not be able to hide it.

 

[leeloo]

The easy solution - a small power pack that you can recharge off the vehicle while driving or from a small solar panel when staying in one spot, even from shore power in a paying camp site.
It is flexible and you can even power a small fridge.
You don't need any electrical skills or to modify your vehicle in any way..
The problem it is taking very long to charge as opposed to dual battery systems - 4-5 h of driving, or shore power or solar, does not matter really the source.
There are even much cheaper smaller versions if you CPAP machine has an 12v input.
If you opt out for this solution, any 60W or maximum 80 w solar panale will do if you think you will need it( for example staying 2-3 days in the same spot with no access to shore power) . Anything bigger is waisted money as most units of this type cant take more amps while charging..
If you only use your CPAP machine it should run 2-3 nights with no charge need it easily..

 

[Shakes355]

Most newer vehicles regardless of brand use "smart charging", it just means the it's controlled by proprietary ecu software instead of the old style voltage regulators. So don't worry about that too much as nice dual setups are used successfully by many people these days without issue. I'd be more worried about warranty issues when hooking up them up since the vehicle is new.

I'd personally spend the money on a Jackery and call it good. After it's all said and done, it's probably cheaper than the whole dual setup and you can choose one large enough to suit your needs. Just plug it into a 12v outlet as you drive and Bob's your uncle. No install. No warranty concerns. And very reliable. Maybe search some of the forums here for other threads related to CPAP use, I've seen a few kicking around.