# Thread: GSA Battery Charging Capacity vs CPAP

1. ## GSA Battery Charging Capacity vs CPAP

I'm asking a bunch of questions in this discussion, sorry I just lack some basic skills in this area. I'm sure a bunch of folks have had to figure this out before - hope you kept some notes.

I am having to learn how to travel and camp with a CPAP. Need to figure out what would be a safe battery capacity to recharge via the GSA alternator on a daily basis. We'll have 110 power off and on, but it might be a week to depend on the recharging.

I'm jumping the gun a little here, I don't have the CPAP machine I'll be using, so I don't know it's power requirements, but I think we are talking scale here. The vendors of CPAP machines with battery support really don't provide any capacity specs..........but, I've read where guys are using the XP-1 below with success. The XP-1 is a lithium starting battery but let's use it as an example.

I've got a 2017 GSA that has two add-on Denali D-4 lights, total 80 watts I believe. I also run a phone and radar detector. Does anyone know the output of the 2017 GSA alternator?

If I used a battery like the Antigravity Batteries' Micro-Start XP-1, can I recharge this unit from a 30% level during say a 5 hour riding day? 12 Amp Hours x 70% = 8.4 AH
Specs on the XP-1:
Battery Capacity:12000mAh (44.4Wh)
Starting Current: 200A
Output5V-1A. 5V-2A, 12V-10A, 19V-3.5A (I assume I'd use the 12V output and 10A draw would be about 10 times what I'd expect to need.)
Input 15V-1A (Does this mean the XP-1 is limited to pulling 1 A?

I'll connect the XP-1 via SAE cables from the battery. No charger or other regulator in line.

Given the stats above, how long should it take to pull 8.4 AH into the XP-1. Anyone know the AH of the OEM GSA battery?

If you use formula to calculate answers, could you include the formula so I could recreate the logic with different specs?

2. River-Runner, I will PM you with the email addy of a good friend of mine who figured out the CPAP battery thing years ago. If he can recharge his CPAP battery with a day ride of only a few hours on his airhead, you’ll have no problem doing the same on a GSA.

Best,
DG

3. I am on my second CPAP, and have also gotten a small travel machine. My original travel machine could run on 12VDC, and I had used it with a Zero Gravity battery. However, my new machine runs on a 24VDC supply, and no portable battery is yet aavailable for it. Just something to keep in mind.

4. Resmed Air mini has a optional battery pack, will recharge from 12volt power supply,you might look at this setup

5. Originally Posted by t6pilot
Resmed Air mini has a optional battery pack, will recharge from 12volt power supply,you might look at this setup
OP. I found a local retailer and will go look at it.

Thanks.

6. Originally Posted by MANICMECHANIC
I am on my second CPAP, and have also gotten a small travel machine. My original travel machine could run on 12VDC, and I had used it with a Zero Gravity battery. However, my new machine runs on a 24VDC supply, and no portable battery is yet aavailable for it. Just something to keep in mind.
Can't you cable two 12-volts to make 24V? Makes things a little more complex.....