Stress testing new Chinese AIOs.

[Luk88]

Does anyone have a good stress test procedure to ensure the quality of the equipment after buying?

When I was buying a tiny 1KW aio for a friend I was very glad I decided to do all the testing on the bench (including 800W heater as load) when the AC charger decided to self destruct.

We simply packed it back in it's box, sent it back and a new one arrived 2 days later (this one smoked the AC charger too, so we returned it for a refund and later bought a a newer model).

I'd much rather find out the device I've got is defective, or being held by bubblegum before I invest lots of time into installing it.

My stress test procedure looks like this:


Power with just the battery, discharge it at full rated continuous power using a resistive heater.


Plug AC and set charging amps to maximum (assuming the battery is fine with it). Observe if it blows up, etc.


If not, discharge again. This time give it a load that briefly takes the surge current spec.


Then try to charge with solar with maximum power.

That's it.

Now I wonder where do I find a load to test the 12kW surge capability of smh-ii-7k (single phase).

 

[wpns]

Now I wonder where do I find a load to test the 12kW surge capability of smh-ii-7k (single phase).

Yeah, some inverters like the EG4 18Kpv can discharge their batteries into the grid, but there aren’t many programmable 20KW-class loads in my budget. Much less enough to give a real workout to a parallel pair.

 

[42OhmsPA]

I've been thinking about how I'm going to put my next pair of 10kW through there paces.
It's been fairly easy with my current single 10kW, just hooked it up to the entire house... The electric dryer, well pump, water distiller, counter convection oven, induction cook top, electric kettle, space heater, heat guns, steam generator, saws, air compressor, shop vac, etc have easily gotten me there.
When I get the pair and hook them up I'll wire the electric range back into the main panel throw a large pizza in the oven while I'm drying some clothes and running a combination of the above loads, if that's not enough I'll throw one of the burner elements on and sauté some onions, peppers and mushrooms to top off the pizza.
After that's all done and I'm fed and happy I'll fill my spray tank and water the garden to keep the well pump going while I use the air compressor to blow out the radiator and clean the air filter on the tractor, might even hack up some crappy lowes lumber with the miter saw; that should take care of the surge load testing.

TLDR - run your house / shop loads like you normally would on an extremely busy day. Keep your IR camera and clamp meter close by and have Solar Assistant running from a redundant power source.

 

[Luk88]

TLDR - run your house / shop loads like you normally would on an extremely busy day. Keep your IR camera and clamp meter close by and have Solar Assistant running from a redundant power source.

Thanks. That is one way, although you need to have it connected to the house already, while I'm trying to test on the bench. I like to be next to the device the first time it gets stressed to hear (and smell) any problems it might have. That would be difficult if I was switching on every bigger load in the house.

I think yours is definitely a good test of the equipment once it has been connected, panels have been made etc.

With, me it usually goes like this:
1. I buy some equipment.
2. I bench test it
3. Substantial amount of time...
4. Equipment gets installed


With very good warranties it doesn't matter when you report, but even with local sellers I'd much prefer to find out I have a faulty unit in the 14 day "consumer return" period. This way I can skip all the extra troubleshooting. I can request a replacement and if it's not the last one they have I always get it.

With Aliexpress (especially on items that "don't enjoy free returns for personal reasons" as they put it) it is, best to be quick too. BTW, I have no idea how Ali can get away with this in the EU. They even modified their terms of service after one of the Eu regulators complained so now it says "EU customers are entitled to 14 day returns", but there is no way to request this unless the seller chooses such option.

Coming back to the topic, I do have a big compressor, but it's 3phase, my induction hob is two phase, and the well pump is just 1kW

 

[42OhmsPA]

Thanks. That is one way, although you need to have it connected to the house already, while I'm trying to test on the bench. I like to be next to the device the first time it gets stressed to hear (and smell) any problems it might have. That would be difficult if I was switching on every bigger load in the house.

I think yours is definitely a good test of the equipment once it has been connected, panels have been made etc.

With, me it usually goes like this:
1. I buy some equipment.
2. I bench test it
3. Substantial amount of time...
4. Equipment gets installed


With very good warranties it doesn't matter when you report, but even with local sellers I'd much prefer to find out I have a faulty unit in the 14 day "consumer return" period. This way I can skip all the extra troubleshooting. I can request a replacement and if it's not the last one they have I always get it.

With Aliexpress (especially on items that "don't enjoy free returns for personal reasons" as they put it) it is, best to be quick too. BTW, I have no idea how Ali can get away with this in the EU. They even modified their terms of service after one of the Eu regulators complained so now it says "EU customers are entitled to 14 day returns", but there is no way to request this unless the seller chooses such option.

Coming back to the topic, I do have a big compressor, but it's 3phase, my induction hob is two phase, and the well pump is just 1kW

Could you pick up some heating elements for a dryer or oven (of various sizes) and use them on the test bench? I suppose you could also use water heater elements.

On your well pump, pay attention to the locked rotor amps / startup surge current (especially if it's a deep well pump).
My pump is only 1HP but the startup current is ~40A for a split second.

 

[Mattb4]

If you have a local rental shop you could rent something that has a heavy draw on startup. Air compressors are notoriously hard to start.

 

[Naraize]

Testing equipment thoroughly before installation is definitely a smart move. It saves a lot of headache down the road. Your procedure seems pretty comprehensive, covering various scenarios to ensure everything's in working order. Have you considered reaching out to the manufacturer for recommendations? Sometimes they can provide specific tools or advice for testing their products. Also, speaking of stressful situations, I would like to say how difficult it is to say no to people with mental disorders. It is quite a difficult situation and periodically many of us face it. Check https://www.mentalhealth.com/disord...-someone-with-borderline-personality-disorder if you have trouble saying no to people with disorders. It's essential to approach such situations with empathy and understanding.