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[Shadow]

I think this is the sort of thing shadow might be interested in.

If you can run a welding rig off the output, things get interesting!

[Lamac]

Hello To All

i am on a project to use my ZERO as a home energy storage.

Its very simple, charge during day with PV,

then use it to power the house on grid or off grid !

All you need is a SMA SB 1,5 inverter

1500 Watt AC ( adjustable with a limit )

This inverter will start at 80 VDC

will post the results later this year !

greetings to all

lamac

[togo]

Thanks Lamac, let us know as you progress.

You must not have many electrical appliances if 1500 watts is enough : - )

[Keith]

OK, I got my 2.5kW inverter today, only took seven days from order to doorstep, FedEx from Wenzhou China to NC, free shipping, wow.  And it works! I hooked it up to a pack with the battery enable trick* and ran 1500W into a hair dryer. For extra fun, I used it to move 1kW from one pack to another. Not useful, but the readouts show the AC output power 1038 watts, 8.89amps, 1.3 volt drop in the SSR (118-116.7), with 107vdc from the source pack. 

2.114kW AC output with the Y cable combining two Quiqs.

* http://electricmotorcycleforum.com/boards/index.php?topic=7116.msg59032#msg59032

[Erasmo]

Nice job Keith.

Thanks Lamac, let us know as you progress.

You must not have many electrical appliances if 1500 watts is enough : - )

For blackouts shouldn't 1500W be enough? You only need to power your fridge, a few lights and a few chargers for you phone etc. The rest is luxury.

[nigezero]

Great test case Keith - we’ll done for being a guinea pig on this, something I’ve been thinking about for ages but wanted to do it bi-directionally so never found the right inverter charger. One thing to beware of is that it’s (more than likely) a very crappy wave shape, with poor protection circuitry and potentially dangerous. Have you put it on an oscillascope?

[Keith]

Don't have a scope these days but I found this on a similar inverter http://www.kerrywong.com/2017/10/01/teardown-and-testing-of-an-800w-puresine-inverter/

Seems pretty well made. Only dangerous thing so far is the DC input terminals, clearly designed for 12V, not 110V. I'll need to cover them! Protection is hard to evaluate without destructive testing, I used to do that to audio power amps. It comes with a whole bunch of spare 10amp fuses so I guess that's the protection. Well, just don't overload it! It ran cool at 2kW.

[Keith]

Here's more fun with my new toys. I got a DC power meter that is pretty cool so I hooked it up to the inverter. What I learned is that the inverter idles at about 30 watts, still draws 10W when switched off and is almost 90% efficient at 1.5kW. All good. The meter will connect wireless for remote battery monitoring, tracks Ah, kWh and has a relay and protection settings. Amazing for the price. https://www.amazon.com/gp/product/B0753CRMWB/ref=ya_st_dp_summary

[togo]

> Don't have a scope these days but I found this on a similar inverter http://www.kerrywong.com/2017/10/01/teardown-and-testing-of-an-800w-puresine-inverter/ ...  Well, just don't overload it! It ran cool at 2kW.

Just to clarify, I assume you are speaking of the 2500w inverter you bought, not the 800w one you just found. : - )

> Here's more fun with my new toys. I got a DC power meter that is pretty cool so I hooked it up to the inverter. What I learned is that the inverter idles at about 30 watts,

Not too bad...

> still draws 10W when switched off

OK, so that's not really off, is it?  That's worse than the worst phone or laptop charger brick I've tested.

> and is almost 90% efficient at 1.5kW. All good. The meter will connect wireless for remote battery monitoring, tracks Ah, kWh and has a relay and protection settings. Amazing for the price. https://www.amazon.com/gp/product/B0753CRMWB/ref=ya_st_dp_summary

Yeah!  Thanks for the update!

PS-

Surprised you got the 30A meter, when the 100A meter is just $1 more

https://www.amazon.com/dp/B0753G4SQ6/

[nigezero]

Don't have a scope these days but I found this on a similar inverter http://www.kerrywong.com/2017/10/01/teardown-and-testing-of-an-800w-puresine-inverter/

Seems pretty well made. Only dangerous thing so far is the DC input terminals, clearly designed for 12V, not 110V. I'll need to cover them! Protection is hard to evaluate without destructive testing, I used to do that to audio power amps. It comes with a whole bunch of spare 10amp fuses so I guess that's the protection. Well, just don't overload it! It ran cool at 2kW.

That’s a pretty good wrap!

[Keith]

Surprised you got the 30A meter, when the 100A meter is just $1 more

Actually I didn't see that version, probably just has a beefier shunt. 100 amps would drain one of my packs in about 20 minutes! But still not enough to wire into the bike which of course I thought about. Oh wait, the bigger deal is the relay, if that's really 100 amps. The relay on mine is rated at 30VDC 30A so it will be damaged if opened at 100V with current flow, DC isn't easy to switch. And the questions have an answer that says this one doesn't include a shunt. And the specs say it can measure 200kW, so who knows but for that price? And I tested the wireless connection, it really works so you could monitor several different batteries with one remote meter. Pictures show a shunt but not a relay so how would it disconnect?

[Keith]

Continuing to test the 2.5kW inverter. I ran it at 1.5kW until the low voltage alarm went off. Spec sheet said 100V but reality for this model is 89.9V as it probably should be. The pack voltage when disconnected was 91.7. I put it in the bike to see what the SOC would read. 93%!!! Right, so the BMS got confused. I rode the bike, turned it on and off, to see if it would reconsider but no, 92%. The throttle response told me it was more like 0%. Anyway I charged it off the bike for a while, put in 500Wh and now it reads 100V and the bike says 35% SOC. OK. The inverter did fine, the fans cycled as you would expect. The AC output voltage was low at the end, 102V but still working. I was going to measure THD, I have an HP333, but it wasn't feeling good after years in the closet. Spec is 5%THD, pretty good I think. I may buy a second unit, I think it is a good deal. I looked into the possibility of phase locking two units and don't see an easy way. The ASIC that generates the 60HZ doesn't have any external sync provision. But I'm still thinking it can be done.

[Shadow]

Running a small MIG welder would be an interesting mobile application... at a guess it would be more than 1500W though.

[togo]

Continuing to test the 2.5kW inverter. I ran it at 1.5kW until the low voltage alarm went off. Spec sheet said 100V but reality for this model is 89.9V as it probably should be. The pack voltage when disconnected was 91.7. I put it in the bike to see what the SOC would read. 93%!!! Right, so the BMS got confused. I rode the bike, turned it on and off, to see if it would reconsider but no, 92%. The throttle response told me it was more like 0%. Anyway I charged it off the bike for a while, put in 500Wh and now it reads 100V and the bike says 35% SOC. OK. The inverter did fine, the fans cycled as you would expect. The AC output voltage was low at the end, 102V but still working. I was going to measure THD, I have an HP333, but it wasn't feeling good after years in the closet. Spec is 5%THD, pretty good I think. I may buy a second unit, I think it is a good deal. I looked into the possibility of phase locking two units and don't see an easy way. The ASIC that generates the 60HZ doesn't have any external sync provision. But I'm still thinking it can be done.

Thanks for the details!  I'm surprised you tried to use the Zero battery at such a low voltage, I'd have fear of damaging the cells.  Did you happen to read balance at low?  Like Luke says, one of the cells has to fall off the cliff first, so imbalance is going to be highest when the battery is discharged, I've seen 99mV on my ZF11.4 pack discharged, hardly ever more than 3mV when charged.

[Keith]

No I didn't check the cell balance. I was a little worried especially since I didn't know how low it would go, only one way to find out. And I think the inverter would have shut down at 85 volts but I didn't have the guts to wait for that, especially with the alarm beeping.So i shut it down myself and charged it immediately, no harm done I think. All in the interest of science of course. If this had been an actual emergency, I would want to know ahead of time what to expect, now I do. And I can set that DC meter to cut off at any voltage, although I think it will burn the relay...