Battery back up for my Remstar M Series

[cajun]

Procrastinated long enough...finally putting together a back up system. My goals are to have it for the (very) rare power outage, and to take it camping. My son is in Scouts, so we may do 1-2 trips that last 1-2 nights. Please let me know if I'm thinking wrong on any of this, or missing any pieces. As of now, looks like the entire system is ~$200.

Power Cord Kit, $44/shipped (ordered) http://www.bestcpapprice.com/Respironic ... _1117.html

Luggage Cart, 175 lbs capacity, $25/shipped (ordered) http://www.shoplet.com/Safco-175lb-Capa ... 057NC/spdv

Battery Tender Jr, $23 (ordered) http://www.walmart.com/ip/Battery-Tende ... r/15779492

27DC marine battery, $80 (need to buy) http://www.walmart.com/ip/EverStart-27D ... y/16795212

Battery Box, $11, (need to buy) http://www.walmart.com/ip/Attwood-Power ... ethod=p13n

[lido14]

I suggest getting a portable 12 volt battery to conserve on space etc. It might cost $100-$200 more up front but you will have flexibility. There are several available now.

[CapnLoki]

...
27DC marine battery, $80 (need to buy) http://www.walmart.com/ip/EverStart-27D ... y/16795212
...

I like the setup. The weak point is the Walmart battery. I've always been skeptical of starting/deep cycle hybrids, which compromise deep cycle performance to put out the high current needed for starting. Also, the concept "maintenance free" really doesn't apply for a flooded battery that's on a charger 24/7. At some point water has to be added. They don't even list the Amp-Hours, though in the Q&A they claim 109 AH, which is in line with its size. I might go for a better looking $100 option:
http://www.sears.com/diehard-marine-dee ... ckType=G10
Unfortunately, there's not way way of telling if either are true deep cycle, or hybrids without cutting them open.

On the other hand, the Walmart low price is tempting and if the battery lives for 3 years or so its earned its keep. It probably won't last as long as a Trojan, but then you won't feel as bad if you kill it prematurely.

I suggest getting a portable 12 volt battery to conserve on space etc. It might cost $100-$200 more up front but you will have flexibility.

Paying twice as much (or more) for a battery with only 10 to 20 Amp-hours is only an advantage if you're back-packing or flying. For home use or "car-camping" a 100 AH battery that can also run a TV or start a car is better. Also, the bigger battery will accept a charge quicker - its can probably accept enough current from an alternator or generator in well under an hour to run a CPAP for a night.

[cajun]

The weak point is the Walmart battery. I might go for a better looking $100 option:

I can't disagree, but like you said, it's a bit of a coin flip on which one will last longer. For $20 less and convenience, I'll stick with the Wmart battery for now. The Wmart batt is rated pretty well, but time will tell.

I have all the pieces now, and just ran the CPAP off the batt. Works great. Now have the batt charging on the tender.

Big thanks to all who have posted about these types of back-up systems! You guys are awesome.

[Nozzelnut]

I have the same battery for my backup system. I purchased the DC PRS1 cable from our site sponsor. Bought my alligator clips/ 12v connector from radio shack. I haven't had a problem with the Everstart; I've had it about 9 months. Longest I've used it was 3 nights (6-7 hours/night); with the heated humidifier. No problems and didn't run it down too low. I like my PRS1 better for using 12v batteries than using my first line Resmed; less of a hassle and less expensive.

I have the battery tender Jr; it will take days to charge your battery; just a heads up. It works better as a trickle charger. I bought the Battery Tender Plus. It will charge my battery in a day or less.

Overall I'm happy with my backup setup. I did purchase an 800 watt inverter so I can run some 120v things around the house in case of power outage so my battery is pulling double duty; instead of getting a dedicated xPAP battery.

[jscholz]

lido14 wrote:
I suggest getting a portable 12 volt battery to conserve on space etc. It might cost $100-$200 more up front but you will have flexibility.

CapnLoki wrote:

Paying twice as much (or more) for a battery with only 10 to 20 Amp-hours is only an advantage if you're back-packing or flying. For home use or "car-camping" a 100 AH battery that can also run a TV or start a car is better. Also, the bigger battery will accept a charge quicker - its can probably accept enough current from an alternator or generator in well under an hour to run a CPAP for a night.

lido14 writes back:
I primarily use it for backpacking, boating, flying where I am without power for 3 -5 days so I paid more to reduce the size and weight.