Portable Power Stations

[jennyjj01]

Sorry folks. I messed up a quote as an edit. I've try to fix it, but nothing really lost.

For now, I'm of the opinion that I want something. It may only be good enough to power some LED house lights and provide for just enough to drive the gas CH if gas is still around but Electricity is off. If I can run a tea cup element long enough to make a mug of tea, that will be a bonus.

For now, I'm tending towards something that will keep a caravan/car battery charged, then I will look at MAYBE getting a 12V caravan fridge, some 12V lamps and a 12V tea maker. The mains inverter might not even feature, and if it does may be a minimal Lidl one or similar.

So. Shopping list:-
18V solar panel (Minimal 100W) There are loads that claim 100W starting as low as £30. I don't believe a word of it.
Current choice, 150W at £120
Solar Charge controller (PWM or MPPT) These start at £8 for what are probably mis-badged PWM
Current choice at £9
Car or caravan battery. I'll probably aim for >65Ah. If TSHTF, would reassign my larger car battery to the role. Target price £70
Selection of Mr16 12V LED lamps and fittings.
12V Kettle and Tea cup element

That should start me off for £200 or so

This is my starter kit, which I HOPE would be enough to provide lights, ample charging facilities and maybe some future hope of running a chiller of some sort.

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..

£9 on a cheap 30A PWM Solar charge controller
£30 on a 25W panel. I KNOW it's not going to give much energy. This is 'speriment. I figure on ~£1 per W of capacity
£9 on a pair of COP LED Rechargeable spotlights, including 18650 batteries. I LOVE these lamps and batteries. Cheaper than last lot ordered.
£6 on a 12V cup immersion heater. Apparently about a 70W load.
I'm in the process of blagging a used car battery, just to make it all work.
Later I'll be buying more Ikea AA cells. LOTS from Ikea.
I'll hold off the inverter idea until I understand more. Taking a leaf out of Jansman's book and just looking to recharge or power some lamps.

Before I go all in and get big expensive panels, I want to get a technical friend to walk me through the maths. I can do watts volts and amps, but get lost after that. I certainly get lost working out solar panel efficiency when the panels are fixed at the wrong angle to the sun.

I need to understand what to expect in real life. I expect to find a situation where I need several days of solar collecting just to get a few hours of usable lamp light. Which is fine. Baby steps. I can always scale up later.

My idea is to use the USB outputs of the controller to charge those 18650 batteries or some AA cells, within the lamps. I don't know whether those Controller USB outputs are powered from the car battery when in darkness.Plenty of measuring and maths to do, which I;ll need help with.

[Yorkshire Andy]

Low tech all the way.

For now, I'm of the opinion that I want something. It may only be good enough to power some LED house lights and provide for just enough to drive the gas CH if gas is still around but Electricity is off. If I can run a tea cup element long enough to make a mug of tea, that will be a bonus.

For now, I'm tending towards something that will keep a caravan/car battery charged, then I will look at MAYBE getting a 12V caravan fridge, some 12V lamps and a 12V tea maker. The mains inverter might not even feature, and if it does may be a minimal Lidl one or similar.

So. Shopping list:-
18V solar panel (Minimal 100W) There are loads that claim 100W starting as low as £30. I don't believe a word of it.
Current choice, 150W at £120
Solar Charge controller (PWM or MPPT) These start at £8 for what are probably mis-badged PWM
Current choice at £9
Car or caravan battery. I'll probably aim for >65Ah. If TSHTF, would reassign my larger car battery to the role. Target price £70
Selection of Mr16 12V LED lamps and fittings.
12V Kettle and Tea cup element

That should start me off for £200 or so

This is my starter kit, which I HOPE would be enough to provide lights, ample charging facilities and maybe some future hope of running a chiller of some sort.

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..

£9 on a cheap 30A PWM Solar charge controller
£30 on a 25W panel. I KNOW it's not going to give much energy. This is 'speriment. I figure on ~£1 per W of capacity
£9 on a pair of COP LED Rechargeable spotlights, including 18650 batteries. I LOVE these lamps and batteries. Cheaper than last lot ordered.
£6 on a 12V cup immersion heater. Apparently about a 70W load.
I'm in the process of blagging a used car battery, just to make it all work.
Later I'll be buying more Ikea AA cells. LOTS from Ikea.
I'll hold off the inverter idea until I understand more. Taking a leaf out of Jansman's book and just looking to recharge or power some lamps.

Before I go all in and get big expensive panels, I want to get a technical friend to walk me through the maths. I can do watts volts and amps, but get lost after that. I certainly get lost working out solar panel efficiency when the panels are fixed at the wrong angle to the sun.

I need to understand what to expect in real life. I expect to find a situation where I need several days of solar collecting just to get a few hours of usable lamp light. Which is fine. Baby steps. I can always scale up later.

My idea is to use the USB outputs of the controller to charge those 18650 batteries or some AA cells, within the lamps. I don't know whether those Controller USB outputs are powered from the car battery when in darkness.Plenty of measuring and maths to do, which I;ll need help with.

If the panel is ok you'll be fine for standby use I started with a 30w photonic universe kit on Mrs A's garden shed it even run a security light when we first got together

[Yorkshire Andy]

Found it

viewtopic.php?p=132399&hilit=Solar+shed ... ht#p132303

[jansman]

The technology available now, is very impressive. And reasonably priced too. Back in the day,I HAD to have a generator I had two at one point ,a little 1 kw job,and a great big site gennie that could power a house. Trouble was,they both had a noise signature,especially the big bu** er! And of course fuel and maintenance was an issue as well. Worst case scenario,what was I going to use my generator for? Running a fridge or freezer ,or lighting,or charging power tools? Even then, it would only be good for as long as there was fuel.

As previously stated,I have low tech workarounds for fridge ,tools etc. Lighting is the big one ,as it has always been for mankind for millennia. Stand alone LED lights rock! Aa batteries x2 in my £8 LED worklights ,that can be recharged via a simple solar panel ( although I have LOTS in storage). And they light a room.In fact ,the light in the pantry needs fixing,but the LED emergency light does the job equally well.

This is where nice ,quiet ways to provide power come to the fore. Pseudonym has purchased a nice one I see,and it’s a lovely stand- alone way to deal with power issues. The gizmos are out there to do what Preppers could only dream of only ten years ago.

Whatever your choice,be it fossil fuelled or modern solar or wind,you need to ask what you NEED to power with it? No way will you power your house the way it is right now when the Grid is functioning.

[jennyjj01]

Found it

viewtopic.php?p=132399&hilit=Solar+shed ... ht#p132303

Thanks Andy. Your photonic 25W kit is £70 and is broadly similar spec to the £30 20W panel and £9 30A controller I ordered, so I'm delighted so far to be on the right track and on budget. I thought someone might deride me for backing down from my initial ambitious plan for Sizewell C. But if I decide to upgrade, I can at any time. I'll keep a lookout for bargain panels. First thing I need to do is get the current measured from that panel to see how far below 25W it turns out to be. If I can get over 0.5A I'll be satisfied. If not, it goes back.
I bought these lamps. I love them and with their Batteries, they are a steal. At nominally 30W, I guesstimate that it would take maybe 3 hours of bright sunlight to give me one hour of running one lamp. Better if I run it on power saving mode mode. One thing I love about those lamps is how they lend themselves to the task of being USB battery chargers in their own right. I don't know how efficient it is passing 12V through a 5V USB stage to charge AA batteries, but it does give a lot of flexibility.

As previously stated,I have low tech workarounds for fridge ,tools etc. ...
Whatever your choice,be it fossil fuelled or modern solar or wind,you need to ask what you NEED to power with it? No way will you power your house the way it is right now when the Grid is functioning.

Once again, Jansman, I especially thank you for talking me down from my ambitious plan. I still expect to expand my solar 'armoury' for flexibility, but will prioritise lighting and who needs mains anyway?. I'll pick up extra stuff as bargains arise, such as maybe at car boot sales or charity shops, or Lidl etc.

Now..... Off to scrounge a car battery and order more AA batteries. 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?

[Yorkshire Andy]

My go to batteries are lidls own brand £1.60 ISH for 8x AA or AAA

[Yorkshire Andy]

When you come to wiring make any cable runs as short at possible to minimise voltage drop to increase efficiency..

You will find on a decent bright day you will get about 2a 12v charging remember the panel puts out somewhere between 18v and 22v so by stepping down you get more amps... my 60w folding solar panel sticks out about 4.5a

When you get the unit set up you will need to program the controller. . This gives you all you need to know

https://m.youtube.com/watch?v=EDl4cN1JREo

[jennyjj01]

You will find on a decent bright day you will get about 2a 12v charging remember the panel puts out somewhere between 18v and 22v so by stepping down you get more amps... my 60w folding solar panel sticks out about 4.5a
https://m.youtube.com/watch?v=EDl4cN1JREo

Doesn't that current increase only happen with MPPT type?
I don't regret buying PWM as it was cheap as chips. £9 compared to MPPT at > £20. As you say, there is a lot of misrepresenting going on.
I'm going to get my techy friend help with current measuring and assessing. If the charge current is higher than the panel current, I understand that would mean it's MPPT.
According to that video, PWM SEEMS to leave the panel disconnected a lot of the time.?

[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...

This is the Voltage trace from my pwm charger over the past week 60w of panels . ....

The discharge over night is the CCTV IP camera

[jennyjj01]

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.