Solar PV Advice

Off Topic Homesteading
#41

Powerjack update

It took me a while to get around to installing the powerjack.

I had previously unbridged the neutral and earth ground in the breaker panel to use the automotive style inverter.

I also needed some new cables, etc.

Anyway, got it installed a couple of weeks ago, and it has been doing daily duty since then (the cabin is 100% solar powered at this point).

So far, the unit seems to be working well.

However, the loads are modest.

The lighting is all LED bulbs. Probably amounts to a couple of hundred watts max with all the lights on.

The major load is a full sized energy star refrigerator which draws around 1100 watts when the compressor is running (with a brief surge significantly higher than that when it starts up).

Also, a box fan which has been running most of the time since it has gotten hot, as well as intermittent loads of a hot plate or crock pot.

The powerjack is installed in the same room as the batteries, inverter, and refrigerator.

It gets pretty warm in there during these 90+ degree days.

And this is the only problem I have seen with the powerjack so far. It will do a thermal reset once or twice a day when it is really hot.

However, it doesnā€™t do this if the internal fan is left on continuously during these hot spells, which is probably why they added the toggle switch for that.

Also, have done an unintentional torture test on the unit. One light fixture was wired up goofy, and when I reconnected the neutral to earth ground in the breaker panel, it creates a dead short whenever the light switch is flipped. I didnā€™t mean to test the powerjack this strenuously but, as it turns out, it handles is OK (surging to 4000 watts on that leg, then doing a self-reset).

So far, very satisfied for the money.

Am thinking about the powerjack 15 KW unit for my next (upgraded) system.

The only complaint I have so far is that the terminals for connecting house wiring seem a little light duty to me. I used 6 Ga wire, and they would barely accept it.

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#42

On the 8kw power jack and also on the 5kw unit I have 2 outlets for plugs and a row of connector blocks that you wire directly into , but my units are 240 volts , but I am sure if you open the unit up and connect a larger cable with heavier duty socket it should be ok .
I have read that people are running workshops with compressors and welders all at the same time on these units so there must be a safe way to do it ā€¦
Dave

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#43

Dave - You had asked me for a picture, but I keep forgetting.

Mine looks exactly like this one:

Except that it has a tiny silver toggle switch for the fan between the two terminal blocks on the lower right side.

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#44

Today I finished getting all the plywood on my generator shed. As I was insulating Tom cā€™s word were continually going through my head about H2 levels from the batteries off gassing. Iā€™m not too worried about tonight because I still have a lot of insulating to do. I do want to seal everything up in 6mil poly.
Once this shed is sealed up, how much do I need to worry? Do I need to worry that the generator will ignite the gas or that I will be affected? Do I leave the windows cracked on both sides during operation? I was hoping to try and keep the shed warm with the diesel engine until I can get to the in floor heat.
I looked online for a continuous sensor but the battery life is only 8 hours for one that I could afford. Are there better solutions that can buy oneā€™s peace of mind?

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#45

Maybe a shroud over the top of the batteries with a small 3" vent pipe going up as a chimney. You might have enough air leaks so that you wouldnā€™t have to add a very small 1" vent in a wall. The air would come in the vent and go across the room, warming as it goes, then into the battery storage area and along with an off gasses, up the chimney. Anyway to circulate air around and out of the battery area with out loosing to much heat. TomC

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#46

Hereā€™s my problem Tom. Because of the sub-zero weather weā€™ve been getting this past week, I have been only been able to get 15% of the 50% of my batteries. I need to keep my batteries at a certain temp to get the optimal battery usage. They say 70F is ideal. I feel if I have an open source to the outside, the batteries will remain cold and operating poorly

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#47

I froze my batteries the first year and ruined them .the replacements came inside 16 years later all is good.

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#48

If you use plastic sealing tubs to put batteryā€™s in you can put a small rubber hose out the top for venting hydrogen goes up rapidly because its very light.

7

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#49

My 04 Buick has the battery under the back seat, vented thru the floor with a small hose. From the factory.

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#50

Bill there are two solar industry standards for venting batteries passive and active. Both involve building a box around them then at the highest point adding a 1.5 inch plumbing pipe sloping upward and piped to the outdoors. To avoid downdraft you can do a small neck downwards outside; not great and can still back draft cold air.
Next : go whole hog and get the certified powered vent : Zephyr Industries Powervent 24V Battery Box Ventilation | altE
Finally mount a computer fan in a tube and build your own ( like mine).
Charged batteries wonā€™t freeze but frozen discharged batteries die a quick death. Is it necessary? Gas will build up how much depends on how tight the building is. Muffin fans are cheap and their draw is tiny.
Best regards, David Baillie

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#51

If you figure out how you are going to get the temperature up and hold a 70 F a small hole even 1/2 inch did. would be good insurance of ā€œsome air to feed the chimney/vent. In Davidā€™s post he has info on a power vent. You donā€™t need that, but look at the add anyway. It shows they used a sheet of plastic to form a hood over the batteries. The natural draft of the 3ā€ chimney will be enough to draw the gass away from the batteries. TomC

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#52

I would look at making a heat recovery ventilator, use 2 of the smallest 12V cooling fans, that way you can assure ventilation and retain the heat, minimal power consumption.

Regards,

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#53

I was pondering it today bill. I would wrap the batteries tight in foam on all 4 sides the charge discharge cycle should keep them warm. It will also reduce the surface area exposed to cold. Maybe monitor just in caseā€¦

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#54

Something permeable like fiberglass insulation should work fine to permit hydrogen (very small) to pass freely while restricting the flow of air. Maybe remove the backing paper.

I wouldnā€™t worry about getting them perfectly insulated, youā€™ve got a massive heat source at your disposal.

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#55

Hereā€™s an interesting article about CO detectors for H2
Maybe I can tear one of these apart and put the alarm part outside?

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#56

No need to tear down a CO sensor.
Here, you can get a whole bunch of different gas sensors for $25:

Then get a $5 Arduino Uno knockoff and make your own sensor, tuned to the exact gas you want to sense.
The link above is only one of dozens that sell the sensors alone.

Just check Ebay with:
ā€œhydrogen gas sensorā€

Pete Stanaitis

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#57

Thanks Pete, thatā€™s pretty cool!
So I see the Arduino link. Do they have an alarm built in them?

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#58

Hello Bill.
No, the simple ā€œMQā€ sensors donā€™t have an alarm built in. They simply send a signal to the Microcontroller which one programs to do whatever you want it to do.

But, if you do look on Ebay, you can find several complete hydrogen sensor setups that do have alarms.
Just a warning about going the Arduino route:
I had never heard of arduino until I got into woodgas and saw that allpowerlabs had made that ā€œkitchen sinkā€ controller for the GEK. I got into arduino myself and it took on a life of itā€™s own!

Pete Stanaitis

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#59

Thanks Pete.
I ordered some up

#60

It warmed up today to 3F and hardly any wind so I got outside and worked on the generator shed. I finished all the insulation and some poly. I took some extra galvanized steel and screwed them to the wall that is near the generator.
Hereā€™s a picture of my battery bank. I have a piece of rubber roofing draped over the top in case some metal drops on the batteries. Itā€™s pulled back for the picture.
Iā€™m thinking of the vent for the off gassing to pull from under the roofing material to push it outside. Maybe the arduino can turn the fan on when it senses the Hydrogen?

IMG_20161215_145703514.jpg3232Ɨ2424 1.66 MB

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