Running my shed off solar...

Bluefoam

I'm considering putting a solar panel on my shed... The most taxing item I have is my Makita dual battery charger (DC18RD), and after that I've a couple of cool led lights I got in Ikea years ago that charge via USB...

Would a 300w (like the linked) unit be enough to charge the Makita batteries? I think the charger draws 240w... 

https://offyourgrid.ie/product/ecoflow-river-2/

greasepalm

Looks nice but only 1 13amp socket and these things are getting very popular now out in the sticks.

Dont know how powerful you need for your jobs.

Bluefoam

https://www.boards.ie/discussion/comment/120541645#Comment_120541645

All my tools are battery operated... I just need to have the charger plugged into it...

greasepalm

Ah so only for charging a battery should be fine and not for boiling a kettle and with everything rechargeable is handy .

Thinking it should but interested what others say

Bluefoam

The way I've calculated it... and I'm no electrician or mathematician...

The generator provides 256 watt hours of power. The charger is 240 watts. I've been told to divide that by . 85 for real world conditions: 282 watt hours... But the 5ah batteries charge in 45 minutes (212 watt hours!?), so in theory, one generator should be capable of charging a set of batteries in one go... It'll then have to recharge via the solar panel. They guarantee the batteries to work for 10 years until they degrade to 80% of original capacity. The numbers seem tight, so just looking for some reassurance.

Lumen

I think you're better off buying a complete kit with all the components sized appropriately e.g.

https://offgridkit.ie/product/complete-12v-230w-system-including-mppt-charger-connectors-120ah-numax-sealed-battery/

Bluefoam

Thanks for that @Lumen That kit does look tempting. I'd worry that there's more to go wrong and more maintenance. It's also considerably more expensive to purchase the parts that way. Budget wise, I'm already pushing it just to charge a couple of batteries...

I've had my sums above verified and it all works out... The whole system is ready to go and I'll get a pair of 100w panels which will improve charging times.

The whole thing is only a couple of components and can be monitored by an app. I value simplicity, so this seems to be a better approach for my needs. I spent the morning yesterday building storage for the shed with pocket holes & it just works out that one of the cubbies is perfectly sized and positioned to allow the generator to fit.

Lumen

Ok, so the plan is to trickle charge the battery in that "charger" from 200W(p) solar, and then periodically dump it into the powertool batteries? Fair enough, if it works 😀

Bluefoam

https://www.boards.ie/discussion/comment/120543400#Comment_120543400

That's pretty much the plan... I can't imagine being able to generate enough power on the roof of a 1500 x 2100 shed to run the batteries directly off solar. Even with a 340w panel...

CrazyEric

https://www.boards.ie/discussion/comment/120543557#Comment_120543557

If I read it correctly the max solar panel input is 110w so you cannot hook up your 2 x 100w solar panels.

AC Charging: 360W

Solar Charging: 110W Max, 11-30V, 8A

Car Charging: Supports 12V Battery, Default 8A

USB-C Charging: 5/9/12/15/20V 3A, 60W Max

Bluefoam

https://www.boards.ie/discussion/comment/120543804#Comment_120543804

Once connected in parallel it'll work grand. The "110W max" on the River 2 refers to the maximum power that that it will draw from the panels, regardless of how much power the panels are capable of producing. The unit will not be damaged by having panels capable of producing more than 110 Watts (i.e. 200 Watts) as long as the voltage is within the specified range of 11-30v.

It'll have improved input on cloudy days and on sunny days it'll be running optimally anyway. 

Bluefoam

Thanks All, I do appreciate the help and suggestions. I chose to go ahead with the EcoFlow River 2 and the 2 x 100w panels (may or may not use both panels). I'll be back on if it all goes drastically wrong!

Bluefoam

Well... The Makita dual charger actually runs at 450w peak, so I went with the higher capacity River 2 Max. It arrived this evening and I tested it at full charge, I depleted the Makita batteries fully and then charged them. Charge time was less than 45 minutes (same as if they were mains charged) & the unit still had 50% capacity once done... This far exceeds my needs & means that the performance of the solar panels is even less critical.

Having said that, if the rain stays off, I'll mount the solar at the weekend and begin test that. I've decided to go with a parallel configuration to manage any shade that may (but shouldn't) come in to play.

eeepaulo

did you order off that offyourgrid.ie website? good experience?

Bluefoam

Great experience, they actually gave me a call after I'd placed the order, just to make sure that I had everything right and to offer alternative configurations if I wanted to consider them... I was very impressed. & I've never witnessed such fast delivery before. It was literally one day...

The Continental Op

Another solution? https://www.lights.ie/p/makita-dc18se-auto-charger-lxt-battery-14-4v-18v.htm

Sorry its an expansive one.

Makes me feel so much better that DeWalt do a similar charger but a bit cheaper.

Bluefoam

https://www.boards.ie/discussion/comment/120556701#Comment_120556701

Thanks, I've never seen that before. My main aim was to be able to charge two batteries at once in my shed... I now have that more than covered. If I ever need to do the same on site or at a location without power, the unit can just be picked up and taken with me.... I can use it anywhere and also have the option to charge it from mains, 12v car, USB C or solar...

I'm thinking of moving into my shed with all this free power (free/not free).

unkel

@Bluefoam - "Once connected in parallel it'll work grand."

Slow down there! The Ecoflow you show has a max amperage of 8A for DC input. So if your panels produce considerably more than half of that each and you have them in parallel, you will blow up your Ecoflow and it won't be covered by warranty. You won't be the first to make that incorrect and costly assumption 😁

Show us the spec sheet of the panels you ordered?

And best of luck with your setup. Most of us started with something cheap on our sheds! I do agree with @Lumen though, particularly if you like tinkering with stuff and there is a chance you will grow your system over time. A €20 second hand car battery, a single second hand panel from DoneDeal or adverts for not an awful lot more than €100, a €20 solar charge controller and a €2 automotive fuse and a cheap second hand low power 12V inverter and some cables should do the trick better than the Ecoflow for a lot less money. Beware though, significant chance it will turn into a hobby!

Bluefoam

Thanks, that's a more considered description, but realistically, I don't want to develop this as a hobby. My shed is 1500 x 2100 and has limited space. I don't want trailing wires, panels on walls and general mess, it's also go the potential to need regular care and has the potential to go wrong. Something like an ecoflow does what I need it to do, very successfully... And gives me more use cases than a homemade system, for instance being able to carry it with you, use it remotely without tethering to the panels, charging in the car if needed... It's just a better option for me. I do get what your saying, but I'm attracted to the simplicity of this. My brother has out a homemade solar system on his shed and it's very limited...

Bluefoam

https://www.boards.ie/discussion/comment/120556911#Comment_120556911

The unit I ended up getting has an input of 13A, but in reality they dump any additional amps and unless you put a huge amount through, the amps won't effect the system. The panels put out 5.9A each, well within the tolerance of the battery pack.

https://offyourgrid.ie/product/ecoflow-river-2-max/

https://offyourgrid.ie/product/ecoflow-100w-rigid-solar-panel/

unkel

Very expensive for what it is though 100wp for €179. I pay less for 400wp. But I guess it will do what you want :-) If it were me I wouldn't buy two of them though.

Bluefoam

https://www.boards.ie/discussion/comment/120558211#Comment_120558211

It's actually €179 for two 100w panels...

Bluefoam

https://www.boards.ie/discussion/comment/120558211#Comment_120558211

I can't see any 400w panels for even close to that price, but I'm no expert in this stuff... the 200 watts of panels seem like reasonably good value to me considering they are branded, have a good distributor and come with a 5 year warranty. Even Chineese panels seem to cost similar if not more.

Bluefoam

Panels went up this afternoon... The sun is threatening to come out, but it's been cloudy... Input has between 60-120watts and it's telling me that from 30-100% charge it'll take between 2-5 hours. Success all round!

unkel

https://www.boards.ie/discussion/comment/120559213#Comment_120559213

Apologies, for two of those that's pretty reasonable. You've done a very neat job installing them, fair play!

Bet you want more solar soon though 😁

Bluefoam

https://www.boards.ie/discussion/comment/120567901#Comment_120567901

I have solar on the house, but it's limited in terms of space. I'm in the process of submitting the NC6, I'm expecting to recoup about €9/month 🤣

CreadanLady

For running a battery charger and a few lights, is it even worth the hassle and expense of solar panels?

You'll never make back the cost on energy units saved. The power needed and the units used would be absolutely trivial.

If I were you I'd just run a cable out from the distribution panel in the house and be done with it. As much reliable power as you want for as long as you want and no fluting around with panels, inverters and batteries.

Bluefoam

https://www.boards.ie/discussion/comment/120658284#Comment_120658284

cost of solar & battery: €500

value in terms of cost: €0

---------------------------------

running a cable: €25

Burying & insulating cable: >€500

I'd prefer to spend the €500 to have the shed independent & not have trailing cables, plus the battery unit is portable and useful for camping/picnics/beach days/neighborhood events/sports days etc. I've had a cable trailing for the past 3 years and I've just cemented in the area it runs past, but I was happier just to loose it and go solar.

unkel

https://www.boards.ie/discussion/comment/120658284#Comment_120658284

You'd be surprised. I'm currently selling some damaged PV panels for €50. Buy a €40 grid tie inverter and plug it into a 3 pin socket. Payback time if you are on 40c per unit electricity is 6-7 months. Plug in today and it will have fully paid for itself before the end of the year.