WARNING to CPAP Users: PREPARE for the Unexpected - When the power goes out

[GWild]

JVinNE -- does that trickle charger have a gel setting? If not, it may bake your $414 battery in a matter of weeks or months. Just sayin'.


As for voltmeters ... can't emphasize enough that you get what you pay for. 1% accuracy is NOT good enough for battery charge tests. Ballpark sure, but not nearly close enough for checking the millivolt difference between 50% vs. 70% capacity. Hidden specs like linearity and monotonic plus the often FS rated misinformation makes the cheapies useless except for charge/no-charge checks. May as well use a test light and save $15.

[GeoffD]

I just got back from the Marine store. I bought a west-marine--15-amp-automatic-battery-charger-with-engine-start-timer--14982045
and a west-marine--gel-deep-cycle-marine-gel-battery, with 97 amp hours at 12v--P015020365

As long as you might be considering going back to the vender, it looks like to me that the model number you listed (if you look on West Marine's website) is the P015020365 model... (look at the list of model numbers on their web page).

According to that list, model P015020365 [on the bottom] is the 31.6 amp hour version for $159.99, not the 97 amp hour version, which they list for $414.99.

If you paid $159.99, you probably got the 31.6 amp-hour version.

Paid $414.99

Ouch!

You can buy 35 amp-hour AGM wheelchair/scooter batteries online for $60-something dollars with free shipping. You can get 105 amp-hours out of three batteries for sub-$200. Just run them in parallel. They only weigh 25 pounds so they are easy to move around.

...and friends don't let friends buy at West Marine. That is the absolute most expensive to buy anything for a boat.

[GWild]

The upside of a GELLED ELECTROLYTE battery is they have extremely low self discharge. They can be charged, then left alone sitting disconnected for 6 months with little loss of charge (1% a month) with little internal damage (no odd sulfation common of AGM and other wet cell tech).

So a gel can be virtually maintenance free, unlike wet cells. And yes, AGM's are almost as bad as fully wet cells when it comes to self discharge and associated damage. AGM's really need a trickle charge and kept full.

[JVinNE]

The upside of a GELLED ELECTROLYTE battery is they have extremely low self discharge. They can be charged, then left alone sitting disconnected for 6 months with little loss of charge (1% a month) with little internal damage (no odd sulfation common of AGM and other wet cell tech).

So a gel can be virtually maintenance free, unlike wet cells. And yes, AGM's are almost as bad as fully wet cells when it comes to self discharge and associated damage. AGM's really need a trickle charge and kept full.

If I leave my gel battery on the trickle charger at all times, will it mess it up? Also, what meter do you recommend I purchase? Thank you.

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JVinNE -- does that trickle charger have a gel setting? If not, it may bake your $414 battery in a matter of weeks or months. Just sayin'.


As for voltmeters ... can't emphasize enough that you get what you pay for. 1% accuracy is NOT good enough for battery charge tests. Ballpark sure, but not nearly close enough for checking the millivolt difference between 50% vs. 70% capacity. Hidden specs like linearity and monotonic plus the often FS rated misinformation makes the cheapies useless except for charge/no-charge checks. May as well use a test light and save $15.

I don't know if it does. Sh*t, this is so frustrating.

[JVinNE]

OK, this seems to be the best one for gel batteries. I looked.

[direct commercial link to Battery Tender 021-0156 on Amazon removed]

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Moderator Action: Link Removed

To maintain our status as an educational organization, the only commercial links allowed in this forum are to CPAP-related manufacturer websites. This is stated in the Apnea Board Rules with details given in the Commercial Links Policy section.

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[OMyMyOHellYes]

Many think the Deltran Battery Tender is the school solution to charging lead acid batteries. I have two a wall wart charger that takes a long time and a 6 amp version that is speedier. They are great.

OMMOHY

[GWild]

The upside of a GELLED ELECTROLYTE battery is they have extremely low self discharge. They can be charged, then left alone sitting disconnected for 6 months with little loss of charge (1% a month) with little internal damage (no odd sulfation common of AGM and other wet cell tech).

So a gel can be virtually maintenance free, unlike wet cells. And yes, AGM's are almost as bad as fully wet cells when it comes to self discharge and associated damage. AGM's really need a trickle charge and kept full.

If I leave my gel battery on the trickle charger at all times, will it mess it up? Also, what meter do you recommend I purchase? Thank you.

---

JVinNE -- does that trickle charger have a gel setting? If not, it may bake your $414 battery in a matter of weeks or months. Just sayin'.


As for voltmeters ... can't emphasize enough that you get what you pay for. 1% accuracy is NOT good enough for battery charge tests. Ballpark sure, but not nearly close enough for checking the millivolt difference between 50% vs. 70% capacity. Hidden specs like linearity and monotonic plus the often FS rated misinformation makes the cheapies useless except for charge/no-charge checks. May as well use a test light and save $15.

I don't know if it does. Sh*t, this is so frustrating.

That Battery Tender has a good reputation. And since it has a GEL setting, I'd probably go with it. Keep in mind you can charge the gel and leave it sit without harming it too much ... and it will hold 94% of its charge for 6 months. I'd be conservative and schedule a recharge at least 3 times a year, and after any use.

Batteries are a deep subject and the manufacturers don't make it easy. If it were your business and having customers destroy and need new batts ... would you do much different? Or if you knew that a small chemistry change means years of life or less internal leakage and that company X had that advantage and company Y didn't? So companies hold their secrets close and say vague things like "Our plate paste is designed to more evenly spread and diffuse HSO4 and reduces Sulfation and the need for equalization." They're basically saying "Our battery lasts longer." But how can we really understand without a degree in chemistry or without access to the actual formulations?

On the other hand - there are really good batts out there that almost last forever - just the average customer won't pay for them. The gel you bought is more than likely above average in quality and build -- but you paid a premium. That isn't a bad thing, as long as you understand it.

Perhaps you can relax and trust your warranty.

I found an article that says West Marine was reselling private label East Penn batteries. Here's an East Penn blurb about charging their Gel batteries - they say 14.6 volts is okay:

http://www.eastpennmanufacturing.com/app...ns/marine/

VRLA Gel Batteries
Valve-Regulated Lead-Acid (VRLA) Gelled-electrolyte batteries offer many significant advantages over conventional “flooded” batteries. Gel batteries are spillproof* and leakproof, and resist over-discharges that can shorten the life of the battery.

Gel batteries have a self-discharge rate of less than 1% per month (at 68°F). They provide ample cranking amperage for quick, sure starts, and deliver longer trolling time than comparable flooded models. Their VRLA design minimizes gassing, making them safe to install around people and sensitive electronic equipment. Gel batteries offer a viable alternative when you can only choose one battery. Gel batteries are maintenance-free.

§ Charge/Absorption/Equalize between 13.8 – 14.6 Volts @ 77°F (25°C).
Float/Standby between 13.4 – 13.6 Volts @ 77°F (25°C).
Temperature corrected charging required.


On the other hand, here's a West Marine advisor column suggesting 14.1 volts max. It is a shame you can't get a straight - and accurate - answer from your West Marine store. Though I am inclined to trust the battery manufacturer over the generic WM article.

[commercial link to West Marine's 'choosing a battery' article removed]

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Moderator Action: Link Removed

To maintain our status as an educational organization, the only commercial links allowed in this forum are to CPAP-related manufacturer websites. This is stated in the Apnea Board Rules with details given in the Commercial Links Policy section.

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[JVinNE]

Thank you.

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If I need a faster charge, would the Cliplight 12 Volt 6 Amp Gel Cell Battery Charger work well?

[GWild]

Thank you.

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If I need a faster charge, would the Cliplight 12 Volt 6 Amp Gel Cell Battery Charger work well?

That WM charger you took back would be better from a warranty/insurance perspective: How could they support a claim you used the wrong charger when they sold it to you?

And, per an un-common knowledge rule, you want a minimum charge of C/10 (temp corrected, of course)... so your 105AH battery wants at least 10 amps during bulk charge phase.

However, a 6 amp charger will work, C/20 doesn't exercise the battery as well and it will never really get to that magic 100% charged level (no big deal for what you are doing -- who cares if it's only got 98.7 AH when you need to use it, it'll still run the apap sans humidore for many days).

[JVinNE]

Thank you.

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If I need a faster charge, would the Cliplight 12 Volt 6 Amp Gel Cell Battery Charger work well?

That WM charger you took back would be better from a warranty/insurance perspective: How could they support a claim you used the wrong charger when they sold it to you?

And, per an un-common knowledge rule, you want a minimum charge of C/10 (temp corrected, of course)... so your 105AH battery wants at least 10 amps during bulk charge phase.

However, a 6 amp charger will work, C/20 doesn't exercise the battery as well and it will never really get to that magic 100% charged level (no big deal for what you are doing -- who cares if it's only got 98.7 AH when you need to use it, it'll still run the apap sans humidore for many days).

I found the Deltran Battery Tender, for gel, at my local auto parts store today, and my converter cable arrived in the post.