Battery Review: N-C18500 Li-Ion CPAP Battery

[AndyCelt]

Since being prescribed a CPAP I have been looking for a battery for extended camping and power outages. The battery I purchased was the N-C18500 Li-Ion CPAP, BiPAP and VPAP BATTERY from the Battery Geeks.



It arrived just a couple of days after I ordered it and came with a nice carrying case, multiple adapters to fit various CPAP, BiPAP and VPAP machines, a manual, a power adapter to charge the battery and a DC cable which can charge the battery from a car or power a CPAP, BiPAP and VPAP machine. Everything seemed to be in order; one note however, the manual consisted of a single page and referenced older battery models. The battery model I purchased was not even mentioned. Not a critical problem but disappointing. Here are my thoughts and observations:

• Longevity: How long will it power the CPAP? With my PR System One REMstar Pro CPAP Machine with C-Flex Plus set at 10cm of pressure I was able to get four full nights and about ¼ of a fifth night from this battery. Obviously with a higher pressure I would get less power and clearly there will be variances depending on what model CPAP, BiPAP or VPAP is used with this battery.
• Portability: This is a huge factor for me because I love camping. There are two factors here, size and weight:
  Size:
  
  The dimensions of the battery are 9.8” x 5.9” x 1.3” which makes it a very small battery for the charge it holds. As you can see it easily fits into a standard backpack and would clearly fit into a larger backpacking pack. I am very pleased with the size.
  
  Weight: 4.8lbs. This is a great weight for a battery as compared to equivalent lead acid or NiMH batteries. However, this will make any backcountry camping a real challenge but it seems to be the best compromise out there in terms of weight/size/performance. I am still cringing at the fact that between this and my actual CPAP machine I have eight extra pounds of equipment to haul wherever I am headed. Well, so be it. Better that than not backpacking at all.
• Safety: according to the salesman and the website the battery has a circuit board to prevent overheating, overcharging and short circuits. This is important for Li-Ion batteries. In the past various companies have had problems with Li-Ion batteries catching fire from overheating. This is also a consideration for tent camping… it would be terrible to have the battery melt the plastic bottom of the tent. Based on the heat from the battery in the morning after running all night I don’t think this battery gets too hot.
• Comes with a full year warranty.
• Uninterruptable power supply: this battery can be left plugged into the wall with the CPAP plugged into this battery so that if there is a power outage, the CPAP continues working without interruption. I’ve tested this and it works as advertised.
• Durability: while the external case certainly seems durable, I have no way of testing this in an empirical manner.
• The battery can be charged in other countries with different voltages. It does not come with the adapter to do so; the correct adapter for the country in question must be purchased separately.
• Allowed on airplanes: I have not tested this yet, I will be doing so in July. However the website states:

  Novuscell Batteries …are DOT and FAA approved for use in airports and on airplanes according to the DOT and FAA rules and regulations pertaining to the acceptable transport of Lithium-ion batteries effective as of 1/1/2008. They will also always clear all airport security checkpoints and will never be affected by the security x-rays.

• Affordability: this is NOT a cheap battery. I figure that is one of the tradeoffs to gain portability and performance.

Overall, I am happy with this battery. It should do everything I want it to do for my purposes.

Although I would recommend this battery and the Battery Geeks to purchase from, I do advise emailing or calling them before purchasing because each machine is different (ResMed machines, as I understand it, need a special adapter to run off of batteries). Depending on your pressure, the performance of any battery will vary and they should be able to help you determine what battery will meet your needs.

It is also important to note that there are drawbacks and limitations to Li-Ion batteries in general. They can sometimes fail for no apparent reason – just stop working altogether. I have never had that happen but I have read of it happening. There is also maintenance for the battery – taking the fully charged battery and fully discharging it and recharging it about once every three months, making sure that when stored for any significant length of time it has half a charge.

I am not affiliated with any battery or CPAP company in any way.

[archangle]

Thanks for the review.

Re: overheating

A lithium battery is not going to get hot enough to melt plastic unless it's having a major malfunction and is about to die. If it gets that hot for whatever reason, the cells will probably have a very short lifetime. It might be warm enough that you wouldn't want to be sleeping on directly on top of it for a few hours. They're also going to get hotter while charging than while discharging, although there will be some heat while they're being used. A CPAP should only discharge the battery slowly, so there will be even less heat problem when using it.

[AndyCelt]

Re: overheating

A lithium battery is not going to get hot enough to melt plastic unless it's having a major malfunction and is about to die. If it gets that hot for whatever reason, the cells will probably have a very short lifetime. It might be warm enough that you wouldn't want to be sleeping on directly on top of it for a few hours. They're also going to get hotter while charging than while discharging, although there will be some heat while they're being used. A CPAP should only discharge the battery slowly, so there will be even less heat problem when using it.

Thank you for explaining the heat and how charging/discharging affects it. When I charge it I will see how hot it gets and add that information if it changes things materially. I did not think the battery was very hot when it was running. I'll have to check and see how hot it is when charging. You know a great deal about batteries!

[tschultz]

Having worked a number of years in the battery industry I would add the following for the (any) Li-ION pack
- keep temperature below 45 degrees C, even in storage (try to avoid direct sunlight) as battery capacity will be degraded and can not be fully recovered
- never charge unattended. Even with the "protection" electronics, internal battery failures are possible and the results can be (are usually) fire.
- if storing the pack try to have approx 75% charge level when starting. A 100% charge at one temperature can actually become an overcharged if the storage temperature goes up by as little at 10 degrees C for any reason.
- recharge every 4 months or so if the manual did not already state this.
- I would hope that their "protection" electronics actually monitors each individual cell and performs cell balancing during charge to ensure optimal life from the pack.

As a general rule these kinds of batteries are expected to yield approx 500 cycles if not abused. Keep in mind however that at this point the pack will have actually lost 80% of its total available capacity. This is what the industry considers end of life for the pack.

[archangle]

As a general rule these kinds of batteries are expected to yield approx 500 cycles if not abused. Keep in mind however that at this point the pack will have actually lost 80% of its total available capacity. This is what the industry considers end of life for the pack.

Lost 80%? YOW!!! As in a 10 Ah battery is now 2 Ah?

Or do you mean "still has 80%?"

[AndyCelt]

Having worked a number of years in the battery industry I would add the following for the (any) Li-ION pack
- keep temperature below 45 degrees C, even in storage (try to avoid direct sunlight) as battery capacity will be degraded and can not be fully recovered
- never charge unattended. Even with the "protection" electronics, internal battery failures are possible and the results can be (are usually) fire.
- if storing the pack try to have approx 75% charge level when starting. A 100% charge at one temperature can actually become an overcharged if the storage temperature goes up by as little at 10 degrees C for any reason.
- recharge every 4 months or so if the manual did not already state this.
- I would hope that their "protection" electronics actually monitors each individual cell and performs cell balancing during charge to ensure optimal life from the pack.

As a general rule these kinds of batteries are expected to yield approx 500 cycles if not abused. Keep in mind however that at this point the pack will have actually lost 80% of its total available capacity. This is what the industry considers end of life for the pack.

Before I purchased I spoke on the phone to a person at Battery Geeks and he gave me very similar advice. He did recommend completely discharging and recharging the battery on a quarterly basis. They claim that the protection electronics do monitor each cell and balances. I have no way of checking that myself though... I just have to take their word on that.

Like archangle, I'd like to know if your last sentence really means that an 10 AH battery is a 2 AH battery at the end of its 500 cycles; thanks.

[archangle]

Before I purchased I spoke on the phone to a person at Battery Geeks and he gave me very similar advice. He did recommend completely discharging and recharging the battery on a quarterly basis. They claim that the protection electronics do monitor each cell and balances. I have no way of checking that myself though... I just have to take their word on that.

By the way, "completely discharge" is ONLY a good idea on these batteries because of the protection circuitry. The protection circuitry will probably stop the discharge before the voltage drops to a level that's bad for the batteries. It's not really a "complete" discharge. If you had an unprotected lithium battery, a complete discharge would probably be fatal for the batteries. It's also one of the forms of abuse that makes unprotected cells likely to catch fire.

[archangle]

Thank you for explaining the heat and how charging/discharging affects it. When I charge it I will see how hot it gets and add that information if it changes things materially. I did not think the battery was very hot when it was running. I'll have to check and see how hot it is when charging. You know a great deal about batteries!

These particular battery packs sound like they're well designed. I wouldn't expect them to get too hot while charging, but it's worth watching. I would be careful not to do something like put the battery inside a backpack or set something on top of it and then charge it. When charging many batteries, once they are nearly fully charged, the batteries start producing heat until the charger shuts down. If you start charging it, and check it, it may not produce much heat. Once it's almost fully charged, it may produce a lot more heat than it did at first.

[TheDreamer]

I've been wanting to get something like this for a while....first it was Battery Geek and then somebody else that made similar but slight higher capacity....so now here's Battery Geek with that stepped up capacity....guess its an arms race on capacity Though what's the limit on airline approved?

I keep saying someday I'll travel, and need one of these....or that I'll just get one anyways as part of my backup power solution (though I had gotten one of those jumpstart batteries with built-in inverters, etc.....but, knock on wood, I haven't used it yet.) I've also thought about getting a backup/travel xPAP machine (been eyeballing the Intellipap Auto)

I did recently finally convince a doctor to write me a new cpap script. At first he was why isn't the one on file with my DME enough to get a replacement, or he didn't think insurance would let me have an extra. I didn't say I was looking at buying from cpap.com, just that I wanted to have one for emergencies or backup that I was going to pay for out of my own pocket. In fact, there was a tornado watch recently where they were talking about keeping us in at work overnight (it was where everybody was when the tornado hit town two years ago, except me...because I was out of town that week.) The hallway outside our office is the designated tornado shelter for the area....and the office is in the basement of a big stone building, and has gas generator backup...where the backup runs the entire basement, not just the datacenter.

However, like the last couple of years, I seem to get smacked with a whole pile of medical bills....have my FSA wiped out in a matter of months...and so I don't have a whole lot for extra spending on one of the batteries or a new xPAP....

My brother had wanted me to visit him this summer in Australia....but that's not going to happen. Not sure my upcoming trip to Las Vegas is enough to need me to get the battery/cpap....

My parents did want me to come and cruise around Hawaii for my dad's 70th...though I don't think I can afford it. Though I used to like cruise travel, and keep saying that someday I'll experience my first with CPAP. Plus I'd rather that I went on a cruise where I could get some enjoyment out of it. Ya...someday I hope to not be sleepy all the time....at least like I was before CPAP....

The solar charger they sell for it, is interesting too....and expensive. Wonder how that would work in a longer term outage? Though not sure how well solar would work for me during the next icepocalyse... Most of my co-workers were without power in the 1-2 week range....I was lucky, was only without power for 16 hours (guess its good I had underground service off of the same overhead that feeds the hospital, one of my co-workers was on that line, but the overhead cable was ripped off of his home...so he was on the 2 week side)

The Dreamer.

[ColoZZZ]

Hi Folks - It's been awhile since I've been on but I have a question:

I'm considering a "Novuscell N-C20000" that's on CL in Denver right now. Here's the battery for sale:
http://www.thebatterygeeks.com/CPAP-Bat ... attery.htm
Does anyone have any info on this battery? Based on the dimensions and weight, it appears to be the same as the one reviewed above but with a slightly different model number. However, I haven't been able to find out how many Ampre Hours capacity it has, only that it's 150 Wh.

I've got a couple of SLABs that I use when camping but would love something that's a little lighter than 15 lbs!

Any info would be greatly appreciated.

Thanks!

-ColoZZZ

[archangle]

However, I haven't been able to find out how many Ampre Hours capacity it has, only that it's 150 Wh.

150 Watt Hours at 12 V is 150/12 = 12.5 Amp Hours.

[BobHale]

Take a look at this battery.
http://www.bestcpapprice.com/Compact-Po ... p_516.html
You can save over $100

[ColoZZZ]

Archangel and Bob,

Thanks so much for your help. Now I know that Wh/V = Ah. Electricity has never been my strong suit...

Wow, I'm surprised the N-C20000 only has 12.5 Ah capacity. I need something to keep me going for at least a couple of nights at 10 cm H2O and I don't think that unit would cut it based on my experience with the 18 and 25 Ah sealed lead acid batteries I've typically used when rafting or car camping.

At 266 Wh, the result is that this is a 22 Ah battery. That should get me through a weekend outing and more with my solar charger!

I'm going to give them a call and ask the following additional info:

• Can it be used as a UPS?
  Does it have internal electronics to prevent total discharge and damage?
  How do the solar / 12V DC charging setups work?
  How many cycles can be expected before reaching 60% capacity?
  Are the complete specs and discharge / lifetime cycle curves available?

Does anyone have anything they'd add to the questions?

Thanks again,

-CZ