Portable Power Stations

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British Red
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Re: Portable Power Stations

Post by British Red »

Yorkshire Andy wrote: Sat May 14, 2022 9:46 pm
They cleaned up with a bit of wet and dry and a bit of light grease
I just started another thread on the importance of knowing how to maintain and repair - it's very clear that your engine knowledge exceeds my own by orders of magnitude 😁

I did think of you today when in the workshop of my real engineer buddy. We were discussing the 1950 battery charger he was using ( he likes modern smart chargers but throws nothing away). He grinned and hauled out his "old" charger. It has valves :o
jennyjj01
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Re: Portable Power Stations

Post by jennyjj01 »

Latest toy arrived yesterday....

Volts/Watts/Amps/Cost power meter. ( £10 )
Image

Bought to help me to understand just how much current and power I need to generate to keep various items alive and to accurately check how much electricity I waste for different items. It's like a per-socket smart meter.

It's already evaluated how much £££ I use/waste with the tumble dryer. :oops: Already paid for itself !

It's also shown me how much the fridge freezers need to run on, including the big burst of current used to start up the freezers
E.g. Modern under counter freezer uses bugger all MOST of the time, but takes 650W for a few seconds to start up and then 130W to tick over. On the basis of measurements, I'll decide what ( cheapest) inverter to buy, and how many panels and batteries. I'm still on my mission to get the best, minimalist, cheapest solar setup :)
Graceful Degradation! Prepping's objective summed up in two words. Turning Disaster into Mild Inconvenience by the power of fore-thought

Not Feeling Optimistic. Let me be wrong
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ukpreppergrrl
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Re: Portable Power Stations

Post by ukpreppergrrl »

jennyjj01 wrote: Fri Jun 10, 2022 11:12 am It's also shown me how much the fridge freezers need to run on, including the big burst of current used to start up the freezers
E.g. Modern under counter freezer uses bugger all MOST of the time, but takes 650W for a few seconds to start up and then 130W to tick over. On the basis of measurements, I'll decide what ( cheapest) inverter to buy, and how many panels and batteries. I'm still on my mission to get the best, minimalist, cheapest solar setup :)
Just some more real world figures to add to your experiments and consider. I have an ice maker (I shall see the apocalypse with ice in my gin or die trying!). It says it's 120watts, I thought it would be fine on my 300w (600w peak) 12v pure sine wave inverter I bought from Maplins years ago. It's not. The moment the compressor starts up it clearly pulls over 600w and trips the inverter. You are wise to get the meter thingy! So given the apocalypse seemed to be coming on apace owing to Chinese flu I splurged on a 1KW (peak 2KW) 12v pure sine wave inverter (Giandel is the model. It cost £135 on Amazon). All was good. My ice maker maketh ice! But I couldn't help but notice two things: 1) the connecting wires were much, much, much fatter than on the 300w inverter; 2) if I plugged in something like the Vango Sizzle induction hob at 800w it would work fine with the inverter on the LiFePo4 12v battery pack, but caused a lot of battery sag on the lead acid 21v batteries to the point that the inverter sometimes cut out. I started to do more research on off-grid and inverters and found out that the consensus of opinion is:

1) Battery sag is a thing that ardent off-gridders only admit very reluctantly! If you pull a lot of power out of your battery quickly, and by "a lot of power" I mean 800 watts at 12v (so the battery is having 67 amps pulled out of it) lead acid batteries struggle to do it reliably. You either need to move to a different battery chemical that can cope with rapid discharging, such as LiFePo4, or up your battery voltage (800 watts at 24 volts is 34 amps, 800 watts at 48 volts is 17 amps). Which brings us to the next point

2) You are limited as to what you can do with a 12v system. 12v is fine and dandy for LED lighting, usb charging, even a bit of 12v tv watching and, I know because I have one, a 12v rice maker (makes fabulous rice)!! It is a great camping and emergency power source. But when you start trying to pull more power out of it you have two problems: battery sag as stated above (even LiFePo4 batteries sag, just not as much as lead acid); and extremely hot whopping amps!! There is a reason the cables on the 1KW 12v inverter were so big, they need to be because the amps that are being pulled are very large. You can buy 2KW 12v inverters, you can buy 3KW 12v inverters. I think you can even buy 4KW 12v inverters, but should you? At 12 volts if you need 1KW of power then you are pulling 83 amps. At 12 volts if you need 2KW of power then you are pulling 167 amps (3KW is 250 amps, 4KW is 333 amps - not sure even a LiFePo4 battery and discharge that rapidly) That's gonna need some very hefty wiring or you're gonna to have a fire. And very hefty wiring costs a LOT of money. More money than more batteries would cost in fact.

The rule of thumb I learned was that 12v is fine up to a 1KW inverter. Above that you should be looking at a 24v system (2KW at 24v is pulling 83 amps) or a 48v system (2KW at 24v is pulling 42 amps). If you are looking to be completely off-grid replicating a normal home, then the sweet spot is 48v (above 48 volts brings other zappy high voltage problems). If you are looking at off-grid lite (e.g. living in a van, on a boat, or being able to run your fridge or freezer and some other stuff when the power goes out), then 24v is the sweet spot. If you're just camping or only need to charge up your phones and power some LED lights and maybe briefly power something requiring a bit more grunt, then 12v is the sweet spot.

With solar people generally say: "you need to work out your power usage and then size your system accordingly", which is, of course true if you're going to live off-grid. But the reality is most of us aren't expecting to live off-grid, or if we are it's off-grid lite whilst we're camping or touring, or we want something that will power SOME stuff when the electricity goes off. And so it's more of a question of "I have this system, what can I run on it?" The well-tried and tested maths are: if you have 12v batteries you can go up to 1KW of power; if you have 24v you can go up to 2-3KW; if you have 48v you can go up to 3-4KW. How long you think you are going to need to run that 1KW or 4KW for before you can recharge determines the Amp Hour size of your battery. But again the tried and tested maths are you'll be ok with a minimum of 100Ah (providing you can recharge every day) but 200Ah or 300Ah will give you more leg room.

For comparison I am guessing the Jackery 1000 is probably something like a 90 Ah 12v Lithium battery which, as they state, is good up to 1KW on the inverter.
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jennyjj01
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Re: Portable Power Stations

Post by jennyjj01 »

ukpreppergrrl wrote: Wed Aug 03, 2022 8:06 pm
jennyjj01 wrote: Fri Jun 10, 2022 11:12 am It's also shown me how much the fridge freezers need to run on, including the big burst of current used to start up the freezers
E.g. Modern under counter freezer uses bugger all MOST of the time, but takes 650W for a few seconds to start up and then 130W to tick over. On the basis of measurements, I'll decide what ( cheapest) inverter to buy, and how many panels and batteries. I'm still on my mission to get the best, minimalist, cheapest solar setup :)
Just some more real world figures to add to your experiments and consider.
ukpreppergrrl, Thank you for a brilliant post!

You've explained very well what I have discovered as my setup has grown. My mind was blown by the current in the 12V side. And realising that I needed super fat quality cables.

I discovered the battery Sag that you mention. I also discovered that there is 'Cable sag': With my 1500W inverter off a new and fully charged 110AH 12V Leisure battery, I was having the inverter trip out. It was voltage dropped in the temp cables that I was using ( A pair of 5ft jump leads. Dropping about 1.3V in each lead, it made the inverter trip out at any load over about 150W !!! I initially though the inverter was faulty or the battery was to blame
Fixed that with Monster Fat 35mm^2 SHORT 600mm leads

You're dead right about the currents drawn. My leads are short as can be and rated about 250A. Custom made at about £8 per short cable.

My project got shelved a while for a covid break, but another 170W of panels goes up this week, bringing me to 270W. I plan to rig a time switch relay, because even from fully charged, my batteries will barely run one fridge freezer overnight, where obviously it gets no solar. Resilience will only be as good as KWHrs of battery capacity. To be totally off grid, I'd need enough to run my load through the night and enough panels to feed the load and charge the batteries during daylight.. That's quite a stretch, so for now I'll supplement energy in from the grid through a scheme which is still in the design stage.
I've actually got a few design ideas in progress of being built..... a Relay to switch my load to regular mains at any time that the battery gets depleted PLUS a regular battery charger on another relay to stop the battery ever getting depleted in the first place, except in grid down. I.e. on a time switch, or maybe triggered by a smart socket. Design decisions depend on whether I'm happy to bring energy in from the grid, and how much to anticipate being off grid. In an ideal world I'll be sucking every possible watt out of my panels and my batteries will stay mostly charged, so they don't wear out. Just used for smoothing until grid down.

I've acquired a second inverter... A 24V one of (I think) 2000W rated That's for another later stage to the project.

So far, lots of pre-owned low price parts. Lots of testing with multimeters and watt meters. Worth their weight in gold. Discovered things like 'energy wasted in the charge controller and energy needed just to have the inverter ticking over.

I've learned SO much by experimenting and interrogating my 'Electrics guy'. It's certainly possible to get A LOT of solar resilience for a tiny fraction of the price of an off the shelf power station. About £300 so far including panels and the spare second inverter.

Incidentally, though my primary load is a 240V fridge freezer, I recognise the terrible waste inverting battery back up to mains. I've already started to discover what can run of native 12V.... LED ceiling lights... Garage door opener,,, Security cameras... Home phones... Router,
I even discovered a 12V small TV in the loft. Evenyually I might buy some 12V appliances. I have a 12V immersion heater for now: ) So that's coffee sorted.
Graceful Degradation! Prepping's objective summed up in two words. Turning Disaster into Mild Inconvenience by the power of fore-thought

Not Feeling Optimistic. Let me be wrong
Yorkshire Andy
Posts: 8736
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Re: Portable Power Stations

Post by Yorkshire Andy »

jennyjj01 wrote: Wed Aug 03, 2022 9:45 pm [I have a 12V immersion heater for now: ) So that's coffee sorted.
But is it ..... Really ...... What you really need is one of these

https://www.planetx.co.uk/i/q/CPPX750PO ... PPX750POCS


I've got one of the bigger versions under the fire maple brand it's bloody ace :lol:

Screenshot_20220803-230626.png
I hammered if for a week solid doing 2x morning brews so 4 cups. Plus kids hot chocolate on a evening, boiled water for washing up at least twice a day . Plus a couple of hand wash smalls sessions in buckets plus boiled water for rice and pasta and I used in the region of half a cartridge which at the cheaper shops are circa £5 each .....

Boils fast and the one above even had a coffees press so you can have a posh coffee and stay caffeinated :lol:


And it's not Amazon or eBay :mrgreen:

Cartridges here under a fiver each

https://www.winfieldsoutdoors.co.uk/col ... pxEALw_wcB

So that's theoretically 12 weeks off brews for £25 ISH in gas


Not that you need one I understand :twisted:
If your roughing it, Your doing it wrong ;)

Lack of planning on your part doesn't make it an emergency on mine
jansman
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Re: Portable Power Stations

Post by jansman »

Yorkshire Andy has a good point there about saving pressure on your solar system. How about an even simpler system? A Kelly Kettle.I have a 1.5 litre one that can be boiling in four and a half minutes,and can be fuelled on paper ,card,twigs and in my case ,kindling for the stoves. Cost to run? Zero. ;)
In three words I can sum up everything I have learned about life: It goes on.

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Covid 19: After that level of weirdness ,any situation is certainly possible.

Me.
Frnc
Posts: 3182
Joined: Sat Mar 12, 2022 1:54 pm

Re: Portable Power Stations

Post by Frnc »

jansman wrote: Thu Aug 04, 2022 5:04 am Yorkshire Andy has a good point there about saving pressure on your solar system. How about an even simpler system? A Kelly Kettle.I have a 1.5 litre one that can be boiling in four and a half minutes,and can be fuelled on paper ,card,twigs and in my case ,kindling for the stoves. Cost to run? Zero. ;)
I havre three stoves that burn twigs. One is round and is a gasifier https://smile.amazon.co.uk/gp/product/B078Q6THFK/. The other two fold flat. One of these is titanium, so very light https://smile.amazon.co.uk/gp/product/B082CXLRJ9/.
Also have a Trangia with a gas canister burner, a mini Trangia (the meths burner from this can be used with the big Trangia), and two other gas canister burners.
I have a ferro rod for lighting fires if I run out of lighters https://smile.amazon.co.uk/gp/product/B00PSGOM32/
Also this can be done with a magnifying glass.

Easy way to get a fire started...cotton wool balls dipped in vaseline. Very flammable. Once you get twigs on you need to blow or fan gently to get oxygen in there to aid combustion, unitil the fire is going strong.
Yorkshire Andy
Posts: 8736
Joined: Thu Oct 03, 2013 4:06 pm

Re: Portable Power Stations

Post by Yorkshire Andy »

As you've probably guessed I have a big selection :lol:

Camping site I booked allows camp fires but being on the edge of a national park when I phoned to confirm our arrival in a few days , the owner said that fires won't be permitted due to the fire risk on the land .. which was fair enough .. gas BBQ was ok as long as it was off the ground same with gas stoves which was fair enough. .. I've seen idiots with BBQs and put out a fire on a camp site where everyone else just sat watching the flames get higher :/



I'm going to start rebuilding my power bank shortly once the postman drops me off a few bits got a duel battery charge controller and remote control / display unit coming some new circuit breakers and what not
If your roughing it, Your doing it wrong ;)

Lack of planning on your part doesn't make it an emergency on mine
jennyjj01
Posts: 3429
Joined: Sun Jun 04, 2017 11:09 pm

Re: Portable Power Stations

Post by jennyjj01 »

Yorkshire Andy wrote: Wed Aug 03, 2022 10:09 pm But is it ..... Really ...... What you really need is one of these

https://www.planetx.co.uk/i/q/CPPX750PO ... PPX750POCS
...
And it's not Amazon or eBay :mrgreen:

Cartridges here under a fiver each

https://www.winfieldsoutdoors.co.uk/col ... pxEALw_wcB

So that's theoretically 12 weeks off brews for £25 ISH in gas


Not that you need one I understand :twisted:
Andy, you B****** !!!!!
:lol:
Shall I just give you my amazon and ebay logins and you can buy me everything you bought yourself?

Actually, I was looking at side-insulated saucepans and this includes one. So I'm tempted.
I like how efficient the burner looks and sounds. Also that pan could sit on my hobo stove..... I'm tempted.

Serious question...... Do those gas carts have unlimited shelf life?
Graceful Degradation! Prepping's objective summed up in two words. Turning Disaster into Mild Inconvenience by the power of fore-thought

Not Feeling Optimistic. Let me be wrong
Yorkshire Andy
Posts: 8736
Joined: Thu Oct 03, 2013 4:06 pm

Re: Portable Power Stations

Post by Yorkshire Andy »

jennyjj01 wrote: Thu Aug 04, 2022 9:54 am
Yorkshire Andy wrote: Wed Aug 03, 2022 10:09 pm But is it ..... Really ...... What you really need is one of these

https://www.planetx.co.uk/i/q/CPPX750PO ... PPX750POCS
...
And it's not Amazon or eBay :mrgreen:

Cartridges here under a fiver each

https://www.winfieldsoutdoors.co.uk/col ... pxEALw_wcB

So that's theoretically 12 weeks off brews for £25 ISH in gas


Not that you need one I understand :twisted:
Andy, you B****** !!!!!
:lol:
Shall I just give you my amazon and ebay logins and you can buy me everything you bought yourself?

Actually, I was looking at side-insulated saucepans and this includes one. So I'm tempted.
I like how efficient the burner looks and sounds. Also that pan could sit on my hobo stove..... I'm tempted.

Serious question...... Do those gas carts have unlimited shelf life?

The neoprene wrap won't like the flame on the hobo stove

20496812173_3cbaae090c_k.jpg
it's a strange base it's got a set of crinkled fins on the base think looking between a double dometic radiator you can almost wrap your hand round it when it's lit I wouldn't want to damage it :lol:

You can get higher efficiency cook sets

https://www.gooutdoors.co.uk/15901577/o ... t-15901577

But it's as much as a full stove set up :lol:


Cartridges last ages I lightly oil them with 3 in one oil
to stave off any rust then just rag them clean when needed

I'm all for sustainable cooking but at 7am if it's cold last thing I'd want to be doing is starting a fire when I can turn a tap on press the spark button as it's boiling get a tea bag has cup ready :lol:

https://www.youtube.com/watch?v=W2IXpxCkwMg



And don't ever click this link

https://www.planetx.co.uk/c/q/bikepacki ... d-cookware
If your roughing it, Your doing it wrong ;)

Lack of planning on your part doesn't make it an emergency on mine