Solar PV battery options

One thing I noticed about OYE is that a lot of their ratings seem to be those one liner, 5 star reviews that are characteristic of bots

Even the ones with pictures look a bit dicey, almost look like the same package from a bunch of different angles

I know there's only so many ways a generic box with identical blue cells inside can look, but still...

PWOD also have a fair number of bot reviews, but there's also a good number of more detailed write-ups that look more realistic. Almost like there was a human in the chair 🤔

So while I don't fully trust the reviews of either, it does look like PWOD gets some better reviews overall

That's not to say that OYE are junk, or that PWOD are automatically good. Just something to consider I would say...

is that 1850/2200 for 10KWh batteries inlduing all the kit parts needed? anything else needed to buy to get up and running?

Not yet, I am sort of reluctant to tell them to update the FW in case they break who knows what else.

Thanks.

Ouch. The math doesn't work for me at that costing. I like the idea of a kit that would be easier for me to follow, the video was great but ... just not worth it until prices come down imho.

As long as you are certain your battery chemistry is LiFePO4, you can store them in your house / attic. Any other chemistry (like Tesla Powerwall) and they must not be installed inside your house at all. That said, my DIY powerwall is LiFePO4 and I have it installed in an outdoor steel cabinet surrounded by 3 stone walls. I also have all my inverters installed on the outside of my house mounted on stone walls.

Whatever you do, your hybrid inverter must be right beside the battery (recommended max cable length 2m) as because the relatively low voltage of the battery, your losses would be horrendous with longer cables.

I totally misread that and thought you had 3 layers of walls around the cabinet

Fortified battery bank 🤣

Lead acid is generally ok in a ventilated room. Not sure how you could fit them into your system, but if you have a garage, shed, barn or any outbuilding really, you could setup a wee off grid system in there for your lights, power tools, etc. Would be a good way to play around with it yourself a bit, without having to spend a fortune on parts. One PV panel and a cheap solar charge controller will do the trick

Shameless plug for a 30A cheap solar charge controller 😁

What about a couple of solar panels on a shed charging the batteries? And then use an inverter to power the lawnmower and other tools

Sending to the grid is very lucrative if you get paid €0.14 / kWh for it, "waste" is the wrong word!!!

If I had huge roof space (farm with large barn or something similar), I'd invest in a setup purely for export.

To be fair I don't think my 6kW output heat pump pulls more than 800W most of the time. It seems to go for the slow and steady approach

It's when the auxiliary heater kicks in that you see the power consumption go way up. Hopefully that's only about 10% of the time in winter, and mostly at night when it's extra cold

There's no real one size fits all answer, but there's a few things you can look at

First I'd be thinking about what your objectives for your system are. If you're hoping purely to save money then probably go for the smallest battery that you can get away with, enough to get you through the evening time until the night rates kick in

You're right to look at consumption, personally I want a battery to cover one days consumption in winter, so I looked at the average daily consumption in December/January and that gave me a battery size of 20kWh

Also, you've an EV right? If so then don't count the EV consumption when figuring out the required battery size. You'll end up with way too much power and there's no logic in discharging your battery to the EV except in an emergency

Unfortunately batteries are pretty expensive so you need to balance this against your budget. In general a bigger battery should allow you to self consume more, or shift consumption to night rates

If you're looking to go off grid, or keep your power on during an extended power cut then you'll probably need a bigger battery, not only for extra capacity, but also because you can only discharge so much power from a battery at one time.

You'll want to ensure the kWh of the battery is equal or greater than any critical loads you'll want during a power cut. A 5kWh battery for example can generally supply 5kW continuously, although it's often better to go for half of this

If you're powering just a few lights and maybe charging phones during a power cut then you'll be fine with a small battery. If you need to do some cooking or heating then you'll probably need more

For anyone who bought battery cells from PWOD, is there any advantage to buying from the EU warehouse other than delivery time?

Ordering from China is a few hundred cheaper, but if I get hit for VAT or other taxes then it's probably not worth it

Is there any difference in the customer service or consumer protection between the two?

We started with a 5kWh battery to see how we went and it certainly helped smooth out the consumption.

We have recently replaced the 5kWh with 9.8kWh and think it is (probably) ample to see us through most evenings with about 40% remaining before any meaningful production covers our base load. Come the darker months we will start load shifting and hope to cover our day time usage before the night rate kicks in.

Leaving aside FIT considerations, for my setup (6.9kwh array + 4.8kwh battery), I reckon a 7.2kwh battery would be the sweet spot to maximise PV usage vrs cost, however there isn't a huge difference in a 2.4 and 4.8kwh additional battery (according to the supplier) if I was going to upgrade.

i was close to getting another 4.8kwh battery earlier in the summer, but with FIT, I'm probably not going to for the foreseeable future.

I think it's making sense to load shift all we can to night (to reduce buying day units and cleaner juice then in general), and then send as much as possible to FIT land. Unless you've a large setup or don't have an EV, or are low usage house (which is a good thing)...most are not gonna be paying tax over the €200 limit I'd guess. 

New Energia D/N night rates are 13c - called them the other day and the 8c ship has sailed, ye lucky sods :) But if a night unit is 13c and FIT is a few cent more, it's pretty much easier to load up at night and sell FIT during the day. The new D/N day rate is 43C. Saucy!! So the battery helps reduce that of course.

so my system will be good to go next week, panels, hybrid solis inverter, no battery.

I am not in a rush to get a battery but that is where my attention will be now.

I know it is not the most difficult thing but I don't have the time to do a total DIY job requiring monitoring batteries, balance batteries, playing with amp meters, worrying about management systems etc. So I suppose I will be looking at power-wall type setups which are more or less plug and play. Is the equivalent of a pure-drive or huaiweii cheaper on Alibaba and of ok quality?

Link?