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Jackery efficiency

David D

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Jul 3, 2021
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Hello folks! I joined the forum specifically to post this question, because I love Will's YouTube channel and straight-shooting smarts. I don't have the resources or ability for solar power at home, and my needs are on the road, portable, for car camping and remote travel in different vehicles, thus a portable solar generator (with maybe on day some solar panels). I have already purchased a Jackery (details below).

My needs: two people using CPAP at night, probably in the range of 45 watts on average between the two, should be able to handle at least 2 nights at 8 hours each. In theory that's 720 Wh needed via the inverter. I considered Jackery, Goal Zero, Bluetti, and EcoFlow, but since the main use case is sleeping at night, and the Bluetti and EcoFlow seem to have loud fans, I ruled those out. Jackery seemed to have better customer service compared to Goal Zero online, and non-techie, non-DIYers seem to be in love with Jackery, so that is the way I went. I would have much rather had better LiFePO4 batteries, but I it is simply a juggling balance of many things, so don't shoot me for the decision! Pretty rugged, reliable, easy to haul around, etc....

With that in mind, and with Jackery's claim of 85% efficiency, I purchased the Explorer 1000. Testing at home with a single CPAP for a few nights, I estimated about 670 Wh effective capacity based on measurements with a new Kill-a-watt P4460. Since that was nowhere near claimed or what I needed, with great effort and terrible customer service, I was finally able to return it. I figured that if the Explorer 1500 had a similar efficiency, that would be about 1000 Wh, which should be more than adequate for my needs. So, for all the same reasons as above, despite the terrible customer service, I then purchased an Explorer 1500, which I have had for almost 2 weeks.

Lo and behold, but the 1500 did little better than the 1000 with the low power CPAP draw, getting about 720 Wh estimated out of the battery using only the AC inverter. I believe that at low power the inverter inefficiencies add up over the hours, and so I tested again with higher power and shorter time, and then with higher power yet again. Basically all of my data is on the attached graphs, and I would love some thoughts about this. Do all AC inverters operate on a logarithmic efficiency scale like this one seems to? With just the CPAP, the fan never turned on. With the lamp, it turned on briefly on occasion, and with the coffee pot, it was on continuously. Can we tell where these inefficiencies are coming from based on this data? Is it solely from the inverter? Is this simple Kill-a-watt meter up to the task? I assume so, since the data is so consistent and clear. Am I missing something here? I have not yet tried doing the math to see how much power the inverter is using at baseline and how much it might be losing as a percentage of the power going through it, and not sure if I need to know that, but any observations would be appreciated.
 

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This makes sense to me. With zero load, my Jackery 1500 will run out of juice in about a week with the inverter running. That equals zero efficiency.
A tiny load will bump the efficiency up just a little. So apparently the 85% efficiency is measured at maximum output. At maximum output, the standby power consumption of the inverter is negligible.
 
So that's why low power 12VDC appliances make a lot more sense to use. Do they make a reliable 12V CPAP?
By the same token, a 12V coffee pot does not make sense.
Also, the inverter does shut itself off after a few hours of no load.
I don't think the low voltage outputs do so.
The Jackery 1500 does not last much longer than the 1000 at low load because the 1500's inverter has a higher parasitic draw so the apparent efficiency is lower.
 
This could be a solution to the problem of the Jackery/CPAP efficiency:

A low power inverter like this $15 one from Walmart plugged into the Jackery 1500 should have many times less parasitic draw.
 
Do you recommend charging the Jackery off a car battery overnight?

I think charging the Jackery with 750 wh of battery power overnight fromthe vehicle would likely ruin a car battery in one night. A typical Battery in a vehicle has less than 1000 wh, and is not deigned for constant draw, so would likely die quicker.
 
Thanks for the great idea, Kevin. I love the idea of buying a low powered DC to AC inverter for this. Basically, fine one with a good enough reputation for quality and efficiency, and then choose a size that is just above my needed output, but with enough headroom that I won't fry the inverter or lose efficiency through overheating on the way to burning up.

Knowing that the DC to DC converters are a lot more efficient than an inverter, and seeing the issues raised in this thread, I am most definitely going to look for a 12V car adapter for the CPAPs (I assume with an inline converter or maybe there is already one inside the machine?), or potentially getting a DC travel CPAP (but any CPAP is really expensive).

Just checked the CPAP input: The CPAPs plug in at home with an inline 90W AC adapter, which outputs 24V 3.75A. It makes so little sense to invert Jackery DC storage to AC output, just to be inverted back to DC in the CPAP inline inverter. Seeing this confirmed, I'm sure that the CPAP maker sells a DC-DC 12V converter. I'm gonna make this work well now, and keep that Jackery inverter reserved for a small coffee pot for the morning after a good night's sleep.
 

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But, I kind of dislike their marketing claims of 85% efficiency, especially since their example is with a "box fan" running at 60W. Noting that actual power consumption varies from different usages does not really explain the huge range of real-world variation from the stated efficiency, especially with the 60W example claiming 85%:

"How do I know the working times for my device?"
A: Working time = 1488Wh* 0.85 / operating wattage of your device
For reference, assuming power consumption of your device is 60W (might be a box fan), working time will be 1488Wh*0.85/60w=21.1hrs (rough calculated) .
Please note: actual power consumption varies from different usages, please consult Jackery for better purchase decision.

I will point out that the 1488 Wh figure does not match the main Explorer 1500 page, which states 1534 Wh. On the Explorer 1000 page, the two values match.
 
My question would be, is the wave form off this unit or a cheap inverter going to be Ok for his Cpap unit or would a better Square Wave Inverter work more efficient.
Also does what ever your going to use need to be portable or will it always be used in the same place?
 
Thanks for the great idea, Kevin. I love the idea of buying a low powered DC to AC inverter for this. Basically, fine one with a good enough reputation for quality and efficiency, and then choose a size that is just above my needed output, but with enough headroom that I won't fry the inverter or lose efficiency through overheating on the way to burning up.

Knowing that the DC to DC converters are a lot more efficient than an inverter, and seeing the issues raised in this thread, I am most definitely going to look for a 12V car adapter for the CPAPs (I assume with an inline converter or maybe there is already one inside the machine?), or potentially getting a DC travel CPAP (but any CPAP is really expensive).

Just checked the CPAP input: The CPAPs plug in at home with an inline 90W AC adapter, which outputs 24V 3.75A. It makes so little sense to invert Jackery DC storage to AC output, just to be inverted back to DC in the CPAP inline inverter. Seeing this confirmed, I'm sure that the CPAP maker sells a DC-DC 12V converter. I'm gonna make this work well now, and keep that Jackery inverter reserved for a small coffee pot for the morning after a good night's sleep.
Hi David. I'm new here. I agree - on such a small DC draw it's perhaps best to look at DC-DC conversion rather than DC-AC-DC. ResMed do sell DC-DC converters in the UK and I would imagine in the US too.

There's also the PowerOak K5 which has a dedicated 24v DC 5.5mm x 2.5mm output port. Mine came with a ResMed DC cable in the box. My personal experience with the K5 has not been great. Sudden drop in capacity and fast battery degradation are amongst some of the issues I have faced. Support from PowerOak has been poor. Drawbacks include no pass-through charging, no solar charging and lack of charging from vehicle. The lack of pass-through charging means if the unit is low, you've no option but to charge the unit and power your CPAP machine individually.
 
Former CPAP user here, with some non solar generator options. A solutionthat might work for one of you, is an oral appliance in lieu of the CPAP machine. I was skeptical of these, but tried one and my O2 levels are fine. Doesn't work for severe SA. Also, the tiny Resmed Air Mini sips power and runs on 24v IIRC. Uses a chemical desiccant for dehumidifier.
 
I'm not sure if available in the US but another DC-DC option would be a Powertraveller Powergorilla. In a nutshell it is a multi-voltage powerbank, though I must admit a bit pricey. It can output @24v, supports daisy chain/pass-through charging and has a built-in MPPT charge controller for solar charging.

I have owned one since 2010. Last week I reviewed the unit and the exceptional customer service of the manufacturer:
 
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My question would be, is the wave form off this unit or a cheap inverter going to be Ok for his Cpap unit or would a better Square Wave Inverter work more efficient.
Also does what ever your going to use need to be portable or will it always be used in the same place?
The Jackery should have a pure sine inverter, which is a good wave form. You do not want a modified sine wave or gasp… a square wave inverter. Many things will not work well on modified sine or square waves (worst).
 
I contacted Jackery support and confirmed that there are 2 forms of the 1500 unit. The early versions, they call 1500A have 1488wh capacity with a DC input that can accept up to 51V but max at 6.25A. The current versions, called 1500B, have just over 1.5kwh capacity and a DC input that takes 24V at 12.5A (it is unknown whether it can accept higher voltage).

Back to efficiency, it appears that the inverter of the 1500 has significant idle wattage, likely around 15W based on the data points provided by the OP. Unfortunately, that consumption is not shown in the output display, unlike goal zero units which does show inverter idle draw (my yeti 400 shows around 5watt when inverter is on without any load). This is unfortunate.
 
It seems the GZ (Yeti x series) shows the AC idle only without a load. If a load is connected the AC shows only the load without the idle.

I have a old AGM Yeti 400, a 500x, a 1000x and a Jackery 1000 too. The 400 and the Jackery displays about 70 watts when I use the TV, the 500x and 1000x showing 54 watts each.

It‘s cracy. The remain run time at the 500 and 1000 according approximately the 54 watts ? The refresh rate of the Yeti x wattmeter is very slow, the Jackery and the old AGM Yeti are very fast.
 
It seems the GZ (Yeti x series) shows the AC idle only without a load. If a load is connected the AC shows only the load without the idle.

I have a old AGM Yeti 400, a 500x, a 1000x and a Jackery 1000 too. The 400 and the Jackery displays about 70 watts when I use the TV, the 500x and 1000x showing 54 watts each.

It‘s cracy. The remain run time at the 500 and 1000 according approximately the 54 watts ? The refresh rate of the Yeti x wattmeter is very slow, the Jackery and the old AGM Yeti are very fast.
You sure about that? It seems like a much harder thing to build rather than just measuring voltage & voltage drop across a known shunt right after the battery to measure total output. You either measure before or after the inverter, measuring both and deciding which one to show base on state would add a bunch of cost/complexity that no one would pay more for.
 
You sure about that? It seems like a much harder thing to build rather than just measuring voltage & voltage drop across a known shunt right after the battery to measure total output. You either measure before or after the inverter, measuring both and deciding which one to show base on state would add a bunch of cost/complexity that no one would pay more for.

Not sure, I guess only.

A easy way is, subtract the idle wattage if a load is plugged in.
 
My experience with Jackery 500 just charged today on 12-volt accessory socket:
Night 1- 6 hours CPAP - remaining power: 85%
Night 2 - 7 hours - remaining - 66%
Night 3 - 2 hours - remaining - 61%
Plugged into van solar 12-volt accessory outlet and took 220 minutes to get to 100% which means .177% per minute, only drawing about 70-85 watts (even though it's a 400ah battery bank). I assume they keep wattage low not to drain a car battery.
Key Point: This is Resmed S9 CPAP WITHOUT heated humidifier attached, because that is what eats up all your power.
It also is good to have the 12-volt adapter for CPAP because that uses less power than the A/C adapter.

I am still doing testing with the EcoDelta.
 
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