Testing The Size 24 Battery With Bi-Pap

[modemem]

Going out to our seasonal site tonight to turn off the 30amp connection and sleep with the bi-pap (without the heater) while using our 450W inverter. I have a 110 outlet on the side of the bed connected to the inverter. This will put our cheap "marine" size 24 battery to the test. The size 27 marine battery in our old motorhome would run the Bi-pap all night with no problem.

If the battery does not survive the night I'm going to replace it with this battery https://www.batteriesplus.com/productdetails/sli27mdc

[bradaz79]

Let me know how it goes please

[modemem]

Originally Posted by bradaz79

Let me know how it goes please

Success. Ran the bi-pap 8hrs, tv for about 3 hrs, fridge on propane all night, and furnace about 3 hrs (it kicked on 4 times). As i walk out of the camper to turn the pedestal back on the battery monitor has three out of four lights lit.

We will be stopping at rest areas and walmarts on trip to florida and back this winter and need the battery to last all night, the truck should renew the charge during next days driving.

[kcmusa]

online calc
https://www.batterystuff.com/kb/tool...to-a-load.html

[Awilson]

Originally Posted by modemem

Success. Ran the bi-pap 8hrs, tv for about 3 hrs, fridge on propane all night, and furnace about 3 hrs (it kicked on 4 times). As i walk out of the camper to turn the pedestal back on the battery monitor has three out of four lights lit.



We will be stopping at rest areas and walmarts on trip to florida and back this winter and need the battery to last all night, the truck should renew the charge during next days driving.

That is awesome! I use a bi-pap but have a 12V adapter for it as I was told mine is already 12V and to take 12V and invert it to 120V to only go back to 12V uses a lot of battery power. I assume he knows what he's talking about as he builds motorhomes and trailers. I have two group 27 batteries and getting a 2000 watt inverter from him to use for a trip to Florida next year and Alaska the next year.

[clintbonnie73]

The first thing I would do is check your battery with a battery Hydrometer.. the battery must be fully charged to do this test.. (AutoZone sells them). Check each cell by removing the fill caps..
If you replace the battery, get two 6v golf cart batteries... (Costco sells them) and you will not have any problems running your bi-pap all nite..

[UT_Grandpa]

In days past we were partners in a houseboat on Lake Powell. One of the owners installed a 2000W inverter in the battery compartment so they could run the microwave and coffee pot instead of the generator ($$$).

One year we followed them in the rotation and it took nearly 3 days of running the generator and the battery charger to replenish the 12 batteries their inverter use ran down. Needless to say the inverter took a swim in the lake and didn't return.

A 2000 watt inverter at full load can pull 200 Amp (worst case) so a single Group 24 battery is junk in 25 minutes unless it has a low voltage cutoff on the inverter.

If the load is more than 150 Watts, I fire the Honda EU2000i up at the end of a really long extension cord. I dislike generator noise but you can't reason yourself out of the laws of physics.

My CPAP runs just fine on two Group 24 batteries (the largest my tongue box can hold) and will recharge in a few hours from my solar setup (165 Watts). My CPAP runs 95 watts with the heater on so a 8 hour sleep takes about 60 AH from my batteries. If I need serious battery life I have two 300 AH Eaton gel cell batteries that are pulls from a commercial solar system. Probably could run them for several nights before charging. The downside is that they weight 100# per battery.

[Awilson]

Originally Posted by UT_Grandpa

In days past we were partners in a houseboat on Lake Powell. One of the owners installed a 2000W inverter in the battery compartment so they could run the microwave and coffee pot instead of the generator ($$$).

One year we followed them in the rotation and it took nearly 3 days of running the generator and the battery charger to replenish the 12 batteries their inverter use ran down. Needless to say the inverter took a swim in the lake and didn't return.

A 2000 watt inverter at full load can pull 200 Amp (worst case) so a single Group 24 battery is junk in 25 minutes unless it has a low voltage cutoff on the inverter.

If the load is more than 150 Watts, I fire the Honda EU2000i up at the end of a really long extension cord. I dislike generator noise but you can't reason yourself out of the laws of physics.

My CPAP runs just fine on two Group 24 batteries (the largest my tongue box can hold) and will recharge in a few hours from my solar setup (165 Watts). My CPAP runs 95 watts with the heater on so a 8 hour sleep takes about 60 AH from my batteries. If I need serious battery life I have two 300 AH Eaton gel cell batteries that are pulls from a commercial solar system. Probably could run them for several nights before charging. The downside is that they weight 100# per battery.

I don't need a 2000 watt inverter as I only plan to use it for the TV system and coffee pot. No need to run microwave or any other high draw electrical appliances. He has it left from another job and I'm getting it dirt cheap. Less than a 1000 watt inverter so why not? Plenty of reserve if/when I can add solar AND run the microwave. Just trying not to undersize and save a few bucks.

[Chuck.C]

That Duracell may in fact be all you need, but don't be fooled by the name. It doesn't seem to be a true Deep Cycle, but rather a somewhat better Marine battery (compared to the junk that is usually installed). If you want real peace of mind, go with a group 24 or 27 from Trojan, or one of the other better manufacturers, and insist that "Marine/RV" isn't in the specs.
I replaced my 2 group 24 house batteries with a single Trojan T1275+, and couldn't be happier.

[Cahriad]

Originally Posted by modemem

Going out to our seasonal site tonight to turn off the 30amp connection and sleep with the bi-pap (without the heater) while using our 450W inverter. I have a 110 outlet on the side of the bed connected to the inverter. This will put our cheap "marine" size 24 battery to the test. The size 27 marine battery in our old motorhome would run the Bi-pap all night with no problem.

If the battery does not survive the night I'm going to replace it with this battery https://www.batteriesplus.com/productdetails/sli27mdc

Be very careful using an inverter. It is best to buy the 12 volt connecter designed for the Bpap. The unit may not like the sine wave the converter puts out. I fried my Resmed by doing this test.

[georandycorbin]

Originally Posted by clintbonnie73

The first thing I would do is check your battery with a battery Hydrometer.. the battery must be fully charged to do this test.. (AutoZone sells them). Check each cell by removing the fill caps..
If you replace the battery, get two 6v golf cart batteries... (Costco sells them) and you will not have any problems running your bi-pap all nite..

Buying batteries this week, so tell me more!
Any additional rewiring or on-board inverter/charger changes needed? I get the series vs. parallel, but any other compromises/advantages? Can you quantify how much better the performance is? Battery boxes still work? Anything else?

[clintbonnie73]

Originally Posted by georandycorbin

Buying batteries this week, so tell me more!
Any additional rewiring or on-board inverter/charger changes needed? I get the series vs. parallel, but any other compromises/advantages? Can you quantify how much better the performance is? Battery boxes still work? Anything else?

No changes needed other than wire the batteries in series.. The batteries are usually the same size, except the 6v are taller (and much heavier) .. new battery boxes would be nice. Had a RV dealer in town tell me the two 6v batteries are the equiv to three 12 v batteries.. or close to it.. I been using them for about ten years now and they are more trouble free and hold a charge longer.. They are a true deep cell battery.
Costco a good place to buy them. (Interstate) however there are better 6v available .. like Trojans..a little more money.
If you do off the grid camping, I would suggest a solar panel with controller, say 100 watts.. and you will keep a good charge on the batteries for several days, depending on what using for power draw.. I made mine portable) not on the roof) so I can following sun. Here is good complete setup:

https://www.amazon.com/dp/B00JML23X0...d=BYFWLHEZIKSN

[FrankMor]

If you are going with a marine cranking/deep cycle battery, look at this one. Group 29 and 18 month free replacement.
https://www.walmart.com/ip/EverStart...-29DC/20531539

Frank

[Jeff_and_Abby]

Originally Posted by georandycorbin

Buying batteries this week, so tell me more!
Any additional rewiring or on-board inverter/charger changes needed? I get the series vs. parallel, but any other compromises/advantages? Can you quantify how much better the performance is? Battery boxes still work? Anything else?

We did what is described in some of the above posts, went with a pair of the Sams Club "Duracell" Golf Cart batteries - they are really Deka / West Penn manufacture. Two in series limited the wiring to adding a single jumper between the two. Also did a frame "upgrade" as we anticipate some particular bumps to our destination ... literally the "last mile" to our boondocking spot is not so kind, plus never know what the roads have in store. Details in this link:

http://www.forestriverforums.com/for...es-141622.html