Solar PV battery options

It’s all properly wired in using the “backup box” that you can buy separately from huawei.

Boiler, Boost Pump, Internet, Lights and Kitchen sockets / Oven are all permanent fed from the “backup” output of the backup box.

Everything else: All the other sockets, Immersion… are dual supply from grid and inverter (via the backup box).

I manually turned off the fridge and boost pump cos if they come on together it’s about 700W; and my wife was going hard on the oven. But the battery can sustain constant discharge of 5kWh and spikes up to 7kwh for 10 seconds or so; but luckily there was a bit of a gap in the clouds and we were pulling in about 600w from solar at the same time.

Tullamore. I think it was an overload at the local substation when everyone put on their ovens at the same time. There was no storm at that time.

It’s the 3rd power outage since I installed all the gear in Feb. Although if it’s winter and later on in the day my battery will be very low; so can’t really depend on it for backup. Can’t just leave capacity sitting unused incase there is an outage. But yeah it was nice to not have the turkey destroyed.

I have access to about 24 lead acid battery’s from an old server room UPS system. They were all housed in a special rack. Is there any situation where these could still be useful? How could I test them?

they have been sitting unused (and not charged I assume they discharge over time?) for prob 6 years.

as they were used in a ups it’s unlikely the were heavily cycled. But I assume they would have been sitting at a high state of charge. I’ll take some photos on Monday.

what degrades them? Cycles? Holding them at a high state of charge isn’t damaging?

they would be free; I’ve an APPARTMENT with a lot of attic space that could easily accommodate them. Would just need to get a hybrid inverter and submit NC6 and I’d be away.

do you think I could sell them? What’s a fair price? I’ll post pics on Monday.

I’m brand new to this thread. Just had a 6kwp system installed last week on a fully south facing unshaded roof. We have a Livoltek 5 kw hybrid inverter. The Livoltek system has option to add their own modular batteries and I think it’s fairly simple to install however I’d like to ask what our options are. I’m interested in installing 10kwh of battery storage.

this is an all electric house with heat pump and high mileage EV so our consumption is 13000kwh a year. No smart meter yet but it’s coming soon.

Nice setup, welcome to the club!

Most proprietary battery / inverter systems like that are very easy to setup DIY once the inverter is installed, just click and play with minimal configuration. Was there any reason you didn't get the battery yet though and have it installed by your installer? And any reason you went with a proprietary system? You are kinda locked in and have very limited options for expansion

Also I would echo what @championc said to get the smart meter ASAP, then a battery will start making economic sense, but that also depends very much on how much you are paying for it. You can buy a very nice high quality complete self assembly kit with 15kWh usable for £1995 delivered to northern Ireland

I understood that it was non proprietary and we could use third party battery although I may be mixed up on that.

I will check inverter.

What do you think?

Sell ASAP 😀

Like I said, some (older) liveaboard boat dwellers or campervan people don't really know about lithium yet or are afraid of it or don't have the money / think lithium is still way more expensive (it is not, lithium is now far cheaper per kWh cycled). They might be interested in good old lead acid. Advertise them as "leisure batteries"

Personally I would clean them up a bit (it looks like they were violently removed from their system) and advertise them for €35 each and accept any reasonable offer you get

I’m gonna bring my multimeter and test the voltages. I’ll randomly pick 5 of them and charge them. And I’m gonna buy a 1200w 12v inverter and run them with a Timelapse pointed at the multimeter.

as far as I understand the time the spent sitting I the rack fully charged wouldn’t of been damaging to them. It’s the time they have been sitting discharged that’s the issue.

I may decide to do nothing with them (other than sell them) but it’s worth a little investigation I think.

80% of 30KWh is 24. And that would have a big impact on my bills in that apartment I mentioned. Or I could add them to my 10KWh of huawei storage in the house to allow me to run a heatpump off night rate power.

i need to determine if they are in a workable state or not.

let’s say I did determine they are working. And I wanted to go ahead. How would you guys recommend I proceed?

I'm with @championc on this one. Like himself I also started out with free lead acids from a UPS system. Was delighted I sold them on quickly enough for plenty of money. But that was 5 years ago when lithium was still quite expensive / exclusive

I wouldn't spend a cent on them or a minute of your time apart from tidying them up, they look like they were ripped out by a bulldozer 🙄 Dump them on DD / FB MP / adverts to anyone who would give you a few shekels. Then use those shekels to buy some proper batteries

You only need one link at the moment, that's for the 14-15kWh of B-grade cells from NKON (Netherlands)

€60 + VAT per cell which is near enough 1kWh. That's under a grand plus VAT!

Then follow the dedicated thread in this forum with detailed instructions of how to put them together

If you fancy something slightly easier, you can buy a complete kit with case and all and everything you need with similar capacity for £1995 with delivery to Northern Ireland

Some or all of those cells appear to be swollen. That's not a massive issue, but it's normally a sign that they have been under a stand-by charge for a long duration. Anyway bringing a multimeter is only going to tell you if there is a completely dead battery or cell, it's no match for a capacity test. I found with many of these second-hand SLAB batteries that they work fine for a few discharge cycles, then die a death pretty quickly.

4 of them gets you to 48v anyway, perfect for your needs.

No you wouldn't have the voltage needed without 16.

Not quite 16. It depends on your inverter. I started with 16, then went 15 and was about to go 14, until I changed my entire setup for another sort of battery altogether - now it's just 12 😀