TravelTalkOnline Forums Travel and Vacation Forums British Virgin Islands C-pap question

One of our guests uses a C-pap. If we charter a non-generator boat (ie, Sunsail '41) > will the house batteries (separate from the engine battery) support one of these? He's trying not to have to purchase a separate portable unit.

thx

It should.

However, most CPAP users would bring along there own portable unit, just in case.

If I were you, I would make it clear that your power supply could fail.

You need to first determine if his Cpap will operate on 12 volts. If it won’t you will need to insure the boat has an inverter. If it has an inverter you should be fine if the battery bank is in good shape. Be warned however that charter boat batteries get abused by over discharge and are often not in the best shape.
Edit: It does not appear the 41 has an inverter. It’s possible Sunsail has not updated their website. I would give them a call.

Also, after making sure you have the power required, good idea to bring a couple power strips and extension cords, you likely won’t need a 50footer, but plugs aren’t always conveniently located. On my last trip (we had a cat with a generator) My parents in law both need cpaps, without a 3ft. Cord and a plug splitter, they would’ve been sleeping separately to both be near a plug.

I just checked CPAP power consumption. 60-90 watts. You can buy a SMALL inverter for few $. Do NOT get a larger one than about 175 watts or so. Reason? A small inverter will power your CPAP from a 12 volt outlet typically seen on boats. Anything larger could overload that circuit (usually 15 AMP maximum) and blow a fuse.

Which you may not be able to find or replace.

This size of inverter is also great for charging cellphones.

The typical charter boat has only a few house bank batteries, and usually these are in bad condition and won't store even close to their rated capacity. Let's assume 3x100Ah battery. Realistically that gives you less than 150Ah capacity to work with (only charged to 90% due to lead-acid and discharge only to 50%).

The CPAP with 90Watts will use 75A over a 10-hour sleep period. That leaves only 75A and with a fridge, freezer and anchor light that is cutting it very close. And if anyone else on board is using or charging smartphones then you'll most likely discharge the batteries before dawn. Do CPAP devices have a low voltage/power acoustic warning?

The CPAPs I have owned haven't had a low voltage/low power acoustic warning. They simply stop.
The acoustic warning comes from me, once I realize the air pressure has stopped!

I would think a battery backup might be cheap insurance to have in case the other ideas don't work!