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Slartybartfast wrote:Belkin says it's a "simulated sine wave," which I suppose is MSW which can mean anything from a stepped square wave to something pretty smooth.

Weasel words. It's a MSW, they're just trying to fool the customer.

SgtWilko wrote:Actually archangle, the problem with MSW inverters is not that they put out a lower voltage (the RMS voltage is the same as the utility sine wave) but rather that they are incompatible with modern Power Factor Corrected (PFC) power supplies found in higher end electronic devices.

I don't agree.

Most DC power supplies, even switchers, will not "see" the RMS voltage, they "see" the peak voltage. A 120V RMS sine wave voltage has a higher peak voltage than a 120V RMS MSW voltage. Almost all DC supplies, even switchers, convert the AC to DC with a diode rectifier circuit followed by filter caps. This kind of circuit "sees" the peak voltage, not the RMS. Then they do more complicated things such as regulation starting working with that rough DC supply.

The more modern CPAP machines with external brick supplies seem to handle MSW voltages very well, since they're usually worldwide voltage capable and handle the lower voltages better.

I believe the reason older AC powered humidifiers have problems is that they use a triac dimmer style circuit to regulate the heating element and that doesn't work properly with a MSW waveform.

avi123 wrote:SB, how do you reach from your bed to operate the S9?

I don't. I never even touch it except to fill the reservoir. Just strap on, take a few deep breaths and it starts right up. In the morning, I take off the mask, the blower goes to max for about 10 seconds, then goes into shutdown mode.

Starlette wrote:@Slartybartfast - Can you rephrase what "maintenance-free" means?

So-called "maintenance-free" batteries don't have filling caps so you can't add water. And you shouldn't need to add water over the life of the battery unless you overcharge the battery. Other than that, there isn't any difference. Deep cycle batteries are constructed a little more ruggedly and usually have filling holes with caps because they're intended to be charged and discharged more heavily than are the maintenance-free type. For the use we're discussing, a Series 24 deep cycle battery in a plastic battery box available from an auto parts store, Wal-Mart, Costco, or Sears will work fine.

There are also absorbent glass mat (AGM) batteries that are spill proof because the acid is contained in a gel form. But they cost more than 2x what a normal battery (called a flooded cell battery) costs.

The plastic battery box is totally impervious to acid and will keep the battery clean and secure.

@ Slartybartfast - Thank you for responding. FINALLY getting the questions I've wanted answered since this whole thing started with Superstorm Sandy.

Another question: Some time ago I contacted Respironics about this whole battery thing. I asked them what battery would they recommend for my auto. They stated a 12V Deep Cycle marine type battery. So, the "Series 24 deep cycle battery" that you stated is it the same as what they recommended to me or different?

Starlette wrote:@ Slartybartfast - Thank you for responding. FINALLY getting the questions I've wanted answered since this whole thing started with Superstorm Sandy.

Another question: Some time ago I contacted Respironics about this whole battery thing. I asked them what battery would they recommend for my auto. They stated a 12V Deep Cycle marine type battery. So, the "Series 24 deep cycle battery" that you stated is it the same as what they recommended to me or different?

My pleasure. Yes, the Series 24 size deep cycle marine battery is indeed the same as the one you were recommended. It's about the same size as you'd find in a full size automobile. Import cars use slightly smaller batteries. There are larger batteries, such as the Series 27, which would be used in, for instance, a motorhome or a truck. And there are smaller deep cycle batteries like the U-1 which are used in motorized wheelchairs and mobility scooters, and as starting batteries in lawn tractors. But the Series 24 is a very common size and because they're so common, they will likely be cheaper than either the smaller or the larger battery. And, importantly, they will be available just about everywhere.

Slartybartfast wrote:

Starlette wrote:@ Slartybartfast - Thank you for responding. FINALLY getting the questions I've wanted answered since this whole thing started with Superstorm Sandy.

Another question: Some time ago I contacted Respironics about this whole battery thing. I asked them what battery would they recommend for my auto. They stated a 12V Deep Cycle marine type battery. So, the "Series 24 deep cycle battery" that you stated is it the same as what they recommended to me or different?

My pleasure. Yes, the Series 24 size deep cycle marine battery is indeed the same as the one you were recommended. It's about the same size as you'd find in a full size automobile. Import cars use slightly smaller batteries. There are larger batteries, such as the Series 27, which would be used in, for instance, a motorhome or a truck. And there are smaller deep cycle batteries like the U-1 which are used in motorized wheelchairs and mobility scooters, and as starting batteries in lawn tractors. But the Series 24 is a very common size and because they're so common, they will likely be cheaper than either the smaller or the larger battery. And, importantly, they will be available just about everywhere.

Hi Slartybartfast!

Great Idea! Great Thread!

I suppose it is the differance between a power supply you could do heavy soldering with and one you could do a light weld with but I do have a bit of concern in using the much greater capacity supply. Designers design with safety in mind - if you make a big change such as you have you may create a safety issue.

Perhaps a carefully chosen breaker between Big Bertha Battery and medium sized UPS would be wise?

Thanks again!

Todzo

Slartybartfast wrote:

avi123 wrote:SB, how do you reach from your bed to operate the S9?

I don't. I never even touch it except to fill the reservoir. Just strap on, take a few deep breaths and it starts right up. In the morning, I take off the mask, the blower goes to max for about 10 seconds, then goes into shutdown mode.

Questions,

1) So when you go to pee at night is the S9 machine left running, or the machine shuts itself off?

2) How would you move your hardware if the weather gets cold (freezes) while the electric power stops, and you decide to move near the fireplace? Most of the power stoppages in my place (NC) occur b/c of frozen tree limbs fall on power lines. Thanks to our fireplace we don't freeze.

3) The gentleman from Oslo says that it's possible to charge the Sears Dieahard JumpStarter 1150, faster than the trickle charger supplied with it (from the 110V AC wall receptacle, to a special socket in the back), by using a fancy charger, connected directly to the alligator clips of the JumpStarter. But the 1150 Operator's Manual says "When Using a 12 V DC cable from the car cigarette lighter to the 12 V DC outlet of the JumpStarter, do not charge for more than 4 hours or leave the battery unattended b/c it could explode" (and you better be near it when it explodes! my addition).

Any thoughts if the fellow from Norway is correct? The trickle charger supplied takes days to recharge the JumpStarter's battery from 60% to 100%.

Link:
http://www.sears.com/diehard-platinum-p ... 871988000P

Lead acid batteries break down the water in the battery into hydrogen and oxygen unless you get the charge just right. That's the main reason you have to add water to a car battery occasionally.

The main thing that makes a battery maintenance free is that they are built with some chemicals to recombine the hydrogen and oxygen back into water so you don't have to add water back to it.

The chemicals can only recombine the hydrogen at a certain rate. If you overcharge them badly, you'll "outrun" the hydrogen recombiner and use up the water. This can even happen to gel cells or AGM batteries.

The most important thing to keep a battery maintenance free is to use the right charger, especially for 24/7 charging.

avi123 wrote:
Questions,

1) So when you go to pee at night is the S9 machine left running, or the machine shuts itself off?

2) How would you move your hardware if the weather gets cold (freezes) while the electric power stops, and you decide to move near the fireplace? Most of the power stoppages in my place (NC) occur b/c of frozen tree limbs fall on power lines. Thanks to our fireplace we don't freeze.

3) The gentleman from Oslo says that it's possible to charge the Sears Dieahard JumpStarter 1150, faster than the trickle charger supplied with it (from the 110V AC wall receptacle, to a special socket in the back), by using a fancy charger, connected directly to the alligator clips of the JumpStarter. But the 1150 Operator's Manual says "When Using a 12 V DC cable from the car cigarette lighter to the 12 V DC outlet of the JumpStarter, do not charge for more than 4 hours or leave the battery unattended b/c it could explode" (and you better be near it when it explodes! my addition).

Any thoughts if the fellow from Norway is correct? The trickle charger supplied takes days to recharge the JumpStarter's battery from 60% to 100%.

Link:
http://www.sears.com/diehard-platinum-p ... 871988000P

Avi,

1) Usually I don't have to get up to "P." But if I do, I simply take off the mask and drop it on my pillow. By the time I've apologized to the cat for disturbing her sleep and stumbled out of the room the machine has shut off. If I wanted to turn it off, I'd simply reach over and hit the button.

2) I'd have to unplug everything, lug the battery and UPS, since they're hard-wired together, to the other room. But I never foresaw any need to ever do so, so I didn't configure my installation to make that easy. The weather in southern California near the beach is boringly mild; the power outages that affect me are the result of drunk drivers running into utility poles and the odd wildfire. Many older homes in town are of single-wall construction, with no insulation and were never built with central heat. I have heard that it's not that way elsewhere in the country.

3) The Sears JumpStarter is almost certainly running a common U-1 lead-acid utility battery (OK it's an expensive AGM battery but same chemistry). There is no circuitry in the charging system that treats the smaller AGM battery more kindly than the car's more rugged flooded cell starting battery. It's never good to connect two batteries in parallel to a single charger. That's why they say don't leave it connected to your car's lighter plug. Charging any battery faster than recommended is not good for it. The slower you charge, the better for the battery. That's one reason I like using the internal UPS battery charger for maintaining the external deep cycle battery I'm using: the charge rate is so low, the battery will not suffer from the effects of charging over its lifetime.

Slartybartfast wrote:

avi123 wrote: 3) The Sears JumpStarter is almost certainly running a common U-1 lead-acid utility battery (OK it's an expensive AGM battery but same chemistry). There is no circuitry in the charging system that treats the smaller AGM battery more kindly than the car's more rugged flooded cell starting battery. It's never good to connect two batteries in parallel to a single charger. That's why they say don't leave it connected to your car's lighter plug. Charging any battery faster than recommended is not good for it. The slower you charge, the better for the battery. That's one reason I like using the internal UPS battery charger for maintaining the external deep cycle battery I'm using: the charge rate is so low, the battery will not suffer from the effects of charging over its lifetime.

Have you disassembled the Diehard 1150 battery or seen the schematic?

I would not be surprised to find that the jumper battery has a "smart" charger circuit that drops back to a "float" mode or does other "smart" things with the current to keep the battery happy. Watching the percent charged indicator as it charges makes me think it may be doing some kind of variable charging steps.

Slartybartfast wrote:

avi123 wrote:
Many older homes in town are of single-wall construction, with no insulation and were never built with central heat. I have heard that it's not that way elsewhere in the country.

If you decide to move to Santa Monica, you will want to be near the non electric fireplace during power stoppage in the winter time.

avi123 wrote:

Slartybartfast wrote:

avi123 wrote:
Many older homes in town are of single-wall construction, with no insulation and were never built with central heat. I have heard that it's not that way elsewhere in the country.

If you decide to move to Santa Monica, you will want to be near the non electric fireplace during power stoppage in the winter time.

Yeah, I've seen those. About as tacky as the plastic pink flamingos people put on their lawns.

Just got back from the wife's place under the big drippy trees in Washington where the roving herds of banana slugs frolic and play. We were glad for the fireplace. And all the trash trees and limbs I cut into firewood over the summer. It was dipping into the mid-40s. I hear if it gets colder water can actually freeze. That really amazes me.

Archangle,

No I haven't seen the inside of the Sears 1150 charger, however the spec sheet says it contains a 22 AH lead acid battery, so it's likely a U-1 since they're about that size, available everywhere and relatively cheap. What makes me wonder about the charging circuitry, though, is the warning to not leave it connected to the car's charging system or the battery might explode. To me that sounds like there's no charge limiting. I think what that warning presumes is the failure of the car's voltage regulator. If it fails and puts out 15 to 17V on the bus, the little U-1 battery will gas off and die of hydrogen/oxygen flatulence before the starting battery will.

Slartybartfast wrote: Archangle,

No I haven't seen the inside of the Sears 1150 charger, however the spec sheet says it contains a 22 AH lead acid battery, so it's likely a U-1 since they're about that size, available everywhere and relatively cheap. What makes me wonder about the charging circuitry, though, is the warning to not leave it connected to the car's charging system or the battery might explode. To me that sounds like there's no charge limiting. I think what that warning presumes is the failure of the car's voltage regulator. If it fails and puts out 15 to 17V on the bus, the little U-1 battery will gas off and die of hydrogen/oxygen flatulence before the starting battery will.

I'm assuming that you're talking about going through a double ended cigarette lighter cord. They explain that "Using this method to charge the battery overrides the maintain mode and the battery can be overcharged." I presume this means it's simply connected between the cigarette plug and the battery with no "smarts" between.

Note also, that it mentions "maintain mode," so that sort of implies something like a "float" mode. Also it says, "The charger will automatically go into maintain mode and maintain the battery at full 4. charge without damaging it." implying a float mode when using the charger, not the DC cord.

I've realized there's a potential safety hazard with this kind of setup. The wires going to the battery may not be "safe" to touch. You should treat the battery wiring on a modified UPS as if the battery and wires have 120 VAC connected to them.

Let me do some background here. When I used to do electrical safety for electronic equipment, there were "customer safe" circuits and "non customer safe" circuits.

For customer safe circuits, there were several requirements. First, the voltage had to be low enough to not be hazardous to the customer. It also had to be safely and reliably isolated from the AC wall current such that the customer couldn't get exposed to those voltages.

It's not just whether there is a dangerous voltage there in normal circumstances. If the customer could touch the wiring, that circuitry had to meet requirements for spacing, type and thickness of insulation between that circuit and the AC mains, and had to survive "Hipot" testing that put a high voltage on the AC input.

You might think that because the internal UPS battery is 12V, there's no risk of electrocution. You can't assume that in this case. There will be 12V between the plus and minus terminals on the battery, but there could be 120 VAC between both terminals with respect to earth ground. Many devices save money by skipping the isolation transformer for their internal DC supply, and even the "low voltage" internal voltages may be hazardous to the touch. Even if they do use an isolation transformer, it may not have the spacing or insulation thickness needed for customer safe voltage. If there is a short or leakage between the AC and DC side, dangerous voltages will be present, but the device will still work.

In a UPS like this, the wiring to the battery is not intended to be exposed to the customer. The wiring to the battery may not be safe to touch. Even if you probe it with a voltmeter, and it's safe when you check it, it might not be reliably safe. It could also be safe if you plug the cord into the wall one way, but not be safe if you turn the plug over.

This would be doubly dangerous if you're using a modified UPS to charge an external battery that you then use to power a CPAP through the DC adapter.