Solar Sheds & Other Non-t6 Solar Projects - How We Done It -

[roadtripper]

UPS ?

Have you considered V2H in the future in your set-up?

Uninterruptible Power Supply - so if the grid supply fails the house battery takes over almost seamlessly. Even if there is a bit of a flicker the core IT already has local higher grade online UPS systems as I rely on them for work.

The difference is that the existing IT UPS run off small lead acid SLA and have a runtime of about 20 mins, they give the NAS enough time to shut down safely and keep the internet active during short glitches, which tends to be mostly what happens during storms. The house battery potentially has run times of several hours depending on how much I want to reserve for that.

I would have liked to tinker with V2H or V2G as currently both our vehicles sit on the drive much of the time. However the i3 is ahead of its time in many ways but only did V2H/G as part of some specialised business trials.

I'm still not used to watching the house draw about 10kw at night as the house battery, overnight washing and EV charging kick in on the heavy days...

 

[Sackmycook]

Yeah, it's a real shame BMW didn't evolve the I3's and others with V2* technology.

I've got a feeling it's going to be a big thing in a decade as storage is not keeping up with generation.

 

[Dellmassive]

That time of year . . . . .



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https://amzn.to/4l6xg6m

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[Vanderlust]

Just a very small solar project I made up a few years ago with a spare leisure battery from our caravaning days and a flexible solar panel bought for some other idea that went in a different direction. Got a battery box that was a bit longer than the lb which gives room for the wiring, 12 v socket and connectors. The plastic box for the dual charge controller is a bit naff but it was during lockdown and just what I had to hand. I use the battery as a 12 volt supply when using tyre inflator or other 12 v kit and saves risking blowing a fuse in the van using one of its 12 v sockets. The charge controller allows the panel to charge the lb and another battery connected with the croc clips.

 

[roadtripper]

That time of year . . . . .

View attachment 280753View attachment 280754

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https://amzn.to/4l6xg6m

View attachment 280811

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Have you ever managed to quantify how much difference it makes in the data?

Just curious as my roof array is now 13 years old and in the annual data doesn't really show any drop in generation due to wear or dirt. If it was easy to clean I would but it's around £100 of kit (or local window washer) and I'm not sure it's really worth that.

 

[Dellmassive]

First two days of 100% solar powered household.

Finally turned off the over night Grid charge to the battery bank.

Slowly decreasing from 4hrs to 30mins.

And now off.

Now using the solar to charge battery and run the house, the battery bank has enough capacity to run the place for 24hrs.... Average 25kwh. Per day.

 

[Dellmassive]

The solar shed is also doing well.

We are now generating more power than the garden lights are using...... So that's now self sufficient.

We're using 3* 100ah 12v lithiums as storage batteries.

But needed to use the NOCO or Victron 12v chargers to keep the bank topped up over the dark winter months.

Now the sun is back out we are doing good.

The solar is 4* 100w rigid frame panels hanging vertical on the side fence.

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[Anakin]

Now I've got the camper electrics sorted, I thought I'd use the spares and odds and sods to do a mini solar shed.
Black Friday Renogy folding panel on the shed roof, old starter battery and old leisure battery hooked up in parallel, cheap inverter and plug timer and now I have a solar powered pond pump.

 

[Sackmycook]

Very similar to my set-up.....
Are the batteries identical ? I was under the impression that they had to be ?

 

[Anakin]

Very similar to my set-up.....
Are the batteries identical ? I was under the impression that they had to be ?

They’re both AGM, but that’s about it. I’ve also read that people have reservations about dissimilar batteries, but as it’s just a shed and I’m not looking for perfection I thought I’d just try it and see. Unless it’s genuinely unsafe?

It’s also wired up with domestic mains cable from the MPPT to the battery at the moment, until better cable turns up later this evening. Proper bodge, just using up spare cable as well. It is fused though!

I’ve got a BM2 monitor coming to keep an eye on the batteries and I’ll put a cheap power meter in there too. The shed roof is also angled away from the sun, so it would probably benefit from propping the panel at a better angle.

 

[Dellmassive]

They’re both AGM, but that’s about it. I’ve also read that people have reservations about dissimilar batteries, but as it’s just a shed and I’m not looking for perfection I thought I’d just try it and see. Unless it’s genuinely unsafe?

As long as they are similar chemistry you should be good..... Ie both AGM

 

[roadtripper]

It's not unsafe if they are the same chemistry, but you'll likely reduce the life of both batteries as the weaker one will parasitically charge from the stronger one when there isn't active charge.

Unless you strongly need the run time you'd be better off using one and keeping the other occasionally charged as a standby/jump.

I have a nearly identical situation with a new and used starter from the XC70 (same panel and MPPT) on the to do list and I'm not going to bank them.

If you can find a 12v pump you'll have a lot more efficiency, you'll be losing a lot of energy through the inverter running just the timer in the off hours. The Victron has some really good options to control it's load terminal output that is worth a tinker with if you do.

 

[Anakin]

I struggled to find a decent 12V pump. I’m planning a bog filter external to the pond, so need the lift height, plus this one has an inbuilt UV lamp.

I only banked the batteries as they were there and I thought I may be better off with the higher capacity. I’ll disconnect them and see how it goes with just one.

 

[roadtripper]

You can get digital timers that will run on 12v DC - most have a 16A relay output. Not sure how that will handle switching a small inverter under load but you could just use it to switch a heavier charge type automotive relay for something a bit more robust.

https://www.amazon.co.uk/Baomain-CN101A-Digital-Programmable-17-Times/dp/B01B165XZS/

Depends on if you are investing or just tinkering with what you have in the parts box

 

[Anakin]

You can get digital timers that will run on 12v DC - most have a 16A relay output. Not sure how that will handle switching a small inverter under load but you could just use it to switch a heavier charge type automotive relay for something a bit more robust.

https://www.amazon.co.uk/Baomain-CN101A-Digital-Programmable-17-Times/dp/B01B165XZS/

Depends on if you are investing or just tinkering with what you have in the parts box

Hmm, I like that idea. I’m up for tinkering and learning new skills. I even caught myself looking at some of @Dellmassive posts on raspberry pi stuff to monitor what’s going on. Not for the need for detailed data, just for fun.

 

[Sackmycook]

Hmm, I like that idea. I’m up for tinkering and learning new skills. I even caught myself looking at some of @Dellmassive posts on raspberry pi stuff to monitor what’s going on. Not for the need for detailed data, just for fun.

....its a slippery slope

 

[roadtripper]

....its a slippery slope

Tinkering and learning new skills is what generally got me the career I have today, which is somewhat adrift from any formal training I've done.

Also a house, garage and shed full of half started projects and an empty wallet - there's always balance in the force

 

[Anakin]

I went to finally tidy things up today. Got rid of the domestic mains cable, downsized the fuse to 10A in a mini fuse holder, shortened the cable runs and split the batteries back up again instead of having them banked. And to my surprise I found that the original SB wasn’t AGM after all, it was an EFB+. I had presumed that as it came from a T6 with stop-start it had to be AGM, but no.

So, I’ve had a wet cell and AGM battery banked for almost a week now, without knowing. So much for only doing this with the same chemistry..luckily, no mishaps and the system has held between 12.7 and 12.9 volts all this time.

 

[roadtripper]

AGM and EFB have broadly the same charging profile so you see them both in Start/Stop systems, but yes not ideal paired.

 

[Anakin]

Having the inverter always powered, and the timer plug was draining the battery unnecessarily, as @roadtripper pointed out. So I also followed his suggestion and wired in a 12V digital timer that only powers up the inverter when needed. A much neater setup. I had to buy another cheap inverter though, as it needed to have a switch that could be set to permanently on, whereas the previous one had to be pressed to switch on each time.