Portable Power Stations

[jennyjj01]

Does anyone know if IKea GREY Ladda batteries are the same great quality as the older white ones? Or indeed if there's a new favourite AA battery source?

To answer my own question.... Word on the web is that the IKEA ladda 2450 AA batteries are quality eneloop pro. At £7 for 4 they still seem great value. Buy direct from IKEA as twice the price on Amazon.

[Yorkshire Andy]

It's basic ohm's law.

V = IR, Voltage is constant, resistance is constant, therefore current (I) has to go down to satisfy ohm's law. Therefore, stepping up voltage results in a proportional step down in current.

You should be able to measure ampage easy enough with a basic multimeter

But have a play see how it goes...

Nice chart. What sort of data logger did that? Is there any equipment you don't have
Did the data logger prove useful in designing your solar gear or was it just one of the tools of your trade?

Will do. I think I get it. If it's mppt the panel voltage will not drop to the battery voltage and since power in = power out, the battery current will be higher than the panel current. If it's pwm, the panel voltage will pulse between 18v or so and battery voltage. Length of the pulse is unknown. I guess on your chart that the spikes on the charging peaks are those pulses. I'm guessing the off on pulses will be slow enough to see . Can hardly wait till my parcels come.

It logs for 15 days ..

60w of panels and the same china charge controller as yours but with The blue stickers





Logger costs about £20 ishif it slow boats from China ..

https://www.ebay.co.uk/itm/374008945657 ... Sw5BZiTrVV

[jennyjj01]

Well, I've invested. Ordered a ridiculously low price bundle, just to see what can be done and to get some ideas into practice.. At worst, I wasted £50 or so on a phone charger..
...
Plenty of measuring and maths to do, which I'll need help with.

Love is....
... A shared carpentry project.

While I await my scrounged car battery, I commissioned my solar panel mounting kit . My bare bones panel was just that . £30 for a naked panel with no clue as to how to mount it. It came with 4 useless looking holes in the frame.

Ten quids worth of Z Brackets from ebay. plus a bag of little bolts. because the bolts with the kit were too big. Add in a bit of strip wood, a few metal fixings and assorted screws and some glue, and we were good to go. I'd like to say it was a team effort, but MrJ gets all the glory for this mount kit. We aimed for something like 40 degrees angle, but that wasn't quite what we got. More like 45 degrees. But no complaints from me. This will get a splash of paint or varnish and then will get screwed to the shed.

Meanwhile, a quick efficiency measurement. On a slightly cloudy midday, connected it to a pp3 battery through a meter and we got about 750 mA. That's far from the rated 25W, but more than I expected. We accidentally shorted it out and for a minute or two, I thought it was ruined because it would not light a 12V LED lamp. But it turned out it had damaged the lamp. So at 750mA, the panel stays. I'm chuffed to bits.

Lovin' this....
By the way, the panel was photographed on a garden table that was made from pallet wood

[Yorkshire Andy]

It's gone

When you said pp3 was that a nicad or NiMH you tried to charge?

You'll probably get 2a out of it once on a flooded battery ..

You'll probably find the led light didn't like the overvolt

[jennyjj01]

It's gone

When you said pp3 was that a nicad or NiMH you tried to charge?

You'll probably get 2a out of it once on a flooded battery ..

You'll probably find the led light didn't like the overvolt

LOL. I'm a bit of an animal. It was just an alkaline pp3, not even a rechargeable.

That was done after we measured current straight from the cell without any load, but I felt uneasy doing that (Short circuit current?). I wanted to know whether having a battery of some sort there would cause the current to drop. The PP3 was all I had to hand. But current didn't drop by much. It rather looks like the solar cell acts pretty much like a constant amps supply limited by the 20V with no load, god knows what amps it would push into a near 20V battery. Similar amps went into a 9V battery as into a ampmeter directly (Short circuit current?) The most we got was 1.02A. By my reckoning, the 25W panel is doing well to push out 1 Amp. No real idea what it will push to a car battery. It's rated about 1.4A peak. So we never expect 2A.
We had previously connected the panel to a 12V MR11? Led lamp and it lit it fairly bright, but just after doing that, the wires touched with a bit of a spark. After that, it would no longer light the lamp and I thought we had bu66ered the panel. But it turned out we had bu66ered the lamp. Phew!

No more 'speriments until I have a car battery to connect to the charge controller. We'll be painting the mounting and fitting it. Probably run some cable into the shed and mount the controller, then wait until Thursday when the battery is due.

I was a bit stumped having the panel, not having given any thoughts to mounting it. Could probably have saved >£10 if I'd not jumped straight on eBay for z brackets. We already had suitable bits of metal bracket in the garage junk cupboard. The 45 degree joints were just bent up 90 degree strips. Four cheap hinges would have been ideal. We have an old, unused satellite dish on the side of the house. That is already pointing south and is well unshaded. We did think of fixing it to that. Maybe next time.
We used nice stripwood because we had some. It was nearly pallet wood.

[British Red]

Tidy job - its great to experiment with this stuff now, when its not "critical" - that way we have a grasp on it when it really matters

[jennyjj01]

Tidy job - its great to experiment with this stuff now, when its not "critical" - that way we have a grasp on it when it really matters

Exactly my attitude.

Small error with this one. It was meant to go above the shed door, but there wasn't room. So for now, it's screwed waist-high while I experiment further with it. I'm now going to be looking out for pre-owned or cheap panels or inverters, now I have a better idea of how it goes together.

There's no such thing as a failed experiment if we learn from them (Except maybe sky-diving). I also learned that this little thing can burn out a cheap 12V LED lamp

[Yorkshire Andy]

Lidl have smart battery chargers in this Sunday for 12v batteries handy for a top up if you need in and still have mains / or subject to rota cuts ..

https://www.lidl.co.uk/p/diy-tools/ulti ... ger/p51840

[pseudonym]

Thanks for the heads up.

[Yorkshire Andy]

Thanks for the heads up.

Also handy for the car or motorbike