Info about Jackery 1000

Socratic Monologue · June 2021

No real issue here, just looking to gain a little knowledge.

I've owned a Jackery 1000 (lithium ion battery/inverter) since last year, and like it. We use it as shore power in the camper, and I was troubleshooting some camper electrical issues and learned that the Jackery actually sends 55vac from each lead to the ground (out of phase, I assume, to total 110vac). I'm glad that the camper turns out to have a floating neutral, or the Jackery would have been an expensive little campfire.

I once hooked up a cheap inverter on our off-grid shed PV system that was the same (that's where I learned about bonded neutrals...), but wanted to know a bit more about this technology. Is it possibly actually pure sine wave as advertised (I realize you can't test it from where you're standing, but is this sort of split phase -- correct term? -- setup possible with PSW)? I'm just looking to understand the pros and cons (and possible deceptive marketing) of this sort of inverter.

Is there anything I shouldn't run on it? We run a basic coffee maker with no electronics (no problems with that, I'm sure -- it is just a resistance heating element), and the camper converter makes 12vdc for everything else to run on (though the three-way fridge can run natively on 120vac -- would that be ok to try?).

I sort of wondered how they packaged 1000wh battery, and a 1000w PSW inverter, and a nice monitor display for the price -- I guess this sort of inverter is part of the compromise. Anyway, any info would be enjoyed.

mike95490 · June 2021

Get a simple electric AC 120V fan, plug it into your house, and listen for noise/vibration, then compare to being plugged into the Jackery. If nosier, the jackery is mod sine.

BB. · June 2021

I could not find a 1,000w Jackery review, but the 500w Jackery they did hang an analyzer on one and the wave form looked like a nice voltage sine wave:

https://www.offgridweb.com/gear/review-jackery-explorer-500-solar-generator/

PSW is "pure sine wave" and TSW is "true sine wave"... Generally a P/TSW inverter is 5% or less THD (total harmonic distortion.

A MSW inverter is "modified square or sine wave" (marketing

). They have something like 25% to 30% or so THD and induction motors, transformer, many "power bricks" and battery chargers do not "like" MSW (they can overheat, run hot, and fail in minutes/hours/months).

For an induction motor/transformer... 30% THD--Means 70% of the power goes though "fine" (transformer/motor)... But 30% "distortion" is usually converted to heat.

And, for the Jackery (and in general any PSW inverter), they do not "care" if you have grounded neutral or not. So don't worry about that. And the 500 Watt Jackery only has AC power connections, there is no electrical contact to the "ground pin" on a North American plug (aka floating AC output). The Jackery sends out 110-120 VAC between the two AC wires. It is floating, so there is no (reliable) voltage between trailer ground the L1/L2 from Jackery. Not 55 VAC from L1 to ground and 55 VAC and L2 and ground... there is not Jackery to ground connection (just like a 12 Volt battery... + to - is 12 volts... Measuring from battery + or - to "ground" has no meaning (unless there is a wire from battery negative to car ground--Then + to ground is 12 volts and - to ground is 0 volts.

MSW inverter--If you have a common ground for a grounded battery bus and "grounded AC neutral"--That will let out the "magic smoke" for most MSW inverter. There is no "electrical isolation" between DC input and AC output and that is the issue with MSW. PSW have "isolated" AC output (i.e., it is a "transformer output") so no "shorts" between DC input and AC output.

"Split Phase power" in North America usually refers to 120/240 VAC 60 Hz power (normal North American Home power). The output is a "center tapped" transformer with the center tap tied to earth ground L1 to N (center-tap) is 120 VAC, L2 to N is 120 VAC, and L1 to L2 is 240VAC.

Nice white paper on split phase power:

https://samlexamerica.com/wp-content/uploads/2019/12/13010-0614_120240VACSingleSplitPhaseandMulti-WireBranchCircuits.pdf

The question is what do you mean by split phase power? With 120 VAC output and no ground reference--It is 120 VAC "floating" output. If there was a Neutral to Ground bond in the trailer, then you would have L1 to ground 120 VAC, and Neutral to ground zero VAC.

If you are very curious... This link for Movie set lighting with portable generators and such is really an interesting and informative read:

http://www.screenlightandgrip.com/html/emailnewsletter_generators.html

-Bill

Socratic Monologue · June 2021

BB. said:

The question is what do you mean by split phase power? With 120 VAC output and no ground reference--It is 120 VAC "floating" output. If there was a Neutral to Ground bond in the trailer, then you would have L1 to ground 120 VAC, and Neutral to ground zero VAC.

Sounds like I'm using the term incorrectly (not surprising; still learning

). I was assuming that because L1 and L2 combine to make the total voltage, then this is split phase. I think I understand the difference between that and 'floating' AC now, though.

Probably boring stuff for some of you, but interesting to me. Thanks!

BB. · June 2021

We are all here to learn and hopefully pass on useful knowledge.

I forgot to answer your other questions...

I would try to avoid any loads that "go over" the Jackery basic rating limits. 1,000 Watts, could start a standard refrigerator (typically around 120 Watts running, and maybe 600 Watts/VA starting surge.

It can probably surge over its rating--But that just puts a strain on everything inside the unit.

Regarding the fridge... Typically 3 way fridge is Propane/120 VAC/12 VDC... Your best bet is to run on Propane/LPG. Three way fridges are "absorption" refrigerators. They have ammonia (and other stuff) internally, and use heat (burner at bottom of fridge and/or 120/12 volt heaters) to drive the absorption cycle. The electric heat is something around 75 Watts or so...

https://www.rvtalk.net/how-does-an-rv-refrigerator-work/

I have never used an absorption fridge--But I gather they run on around 0.5 to 1.0 lbs of propane per day... Not a lot.

75 Watts on your Jackery would be something like:

1,000 WH stored energy / 75 Watts = ~13 hours best case (full charge, low losses)

So--Probably using a 1/4 to 1/2 lb of propane instead is not going to hurt anyone's feelings.

The fridge itself, may use 12 VDC to run the "brains" (thermostat, igniter) of the fridge... So watch your DC house battery and make sure the fridge does not take it low unexpectedly.

The above is brand/model dependent--So just some average numbers for the discussion.

Have fun,
-Bill

Info about Jackery 1000

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