Which home energy storage battery?

[Andy]

For the OP I have gone with pylon tech and victron. For the same reason as others, I don't like being locked in and both the Pylon tech and Victron give me the flexibility I require.

In real life, assuming that there is some reality in the claim of 3500 cycles, that represents a life much greater than 10 years in domestic applications, unless your battery is so undersized that you give it a complete discharge every day.

You need to be careful with your assumptions . I have a 38kWh battery that is discharged from 100% to 15% every day. Any bigger battery isn't cost effective so they are sized correctly. It is more common to use batteries hard these days for time shifting in the winter.

Unfortunately the 6000 cycle lifespan for the pylon tech doesn't give any information for what is assumed to be SOH etc at that point. Most of what I read seems to be conjecture unless someone can point me to something concrete I have missed.

[Andy]

Our plylontechs (oldest unit) is 5yrs 3mths. I run them down to 10% soc and have done since purchase, they are often discharged down this low, not so much in last year but certainly 4 years of being caned. . My inverter says they have a SOH of 90%. They've discharged 19Mwh so far.

Might help someone.

Have you been recording cycles? I've been logging since the start so will try and post a summary every year so people can see the real life performance. I think there is a way by interfacing directly with the batteries from a laptop. I don't have the correct dongle + software so have been estimating it with the changes in SOC. Not a 100% accurate but will hopefully give a reasonable idea.

[Colin Deng]

Can enjoy the DIY of your own battery pack
Or can get the already made battery pack home, right now many China supplier has stock in EU market
Last working day of 2023
Hope everyone has a wonderful 2024

[Joeboy]

Our plylontechs (oldest unit) is 5yrs 3mths. I run them down to 10% soc and have done since purchase, they are often discharged down this low, not so much in last year but certainly 4 years of being caned. . My inverter says they have a SOH of 90%. They've discharged 19Mwh so far.

Might help someone.

Have you been recording cycles? I've been logging since the start so will try and post a summary every year so people can see the real life performance. I think there is a way by interfacing directly with the batteries from a laptop. I don't have the correct dongle + software so have been estimating it with the changes in SOC. Not a 100% accurate but will hopefully give a reasonable idea.

No Andy, I didn't bother. 1,825 cycles going on one per day so far. Not quite in keeping with the 4,000 cycle promise at 90% discharge. Close though. 80% soh will likely be my Q to buy another diy pack at the increased density available then. I expect to see a drop off in degradation due to the diy pack addition. We often finish days with 40% soc across the stack now.

So far we've ran 19.15MWh through them. Hard to capture that in cash terms but maybe something like this. Half from PV gen at 20p per kWh value. The other half bought at 7.5p per kWh.

That pops out at £3,111 not handed to suppliers. Strangely when I say suppliers, I visualise Scottish Power and feel loathing. Not Octopus as reality is now.

[Mart]

Thanks for the comments on Fogstar. Obviously I was attracted by the price, and package, but I know that's just a starting point.

With regard to the cycles, I have to say I find this a bit frustrating, as different 'rules' seem to be used by different suppliers. I note that in this case, they don't give a discharge %age, so 3,500 cycles may be poor for 20%-80% use, but excellent for 0%-100%. However I see that it's at 200A, which is nearly ~9.6kW for these 15.5kWh units, which sounds brutal, to me? I'd guess at a max discharge for my uses of ~5kW, and perhaps shared across 3 of these battery units. Am I right in thinking that a discharge rate of around 1/5th would (could) result in more life cycles?

Also been following the Givenergy prices which are looking good. The Tesla Powerwall II is OK, as a package, but still too expensive (I think) at £6k for 13.5kWh useable. Plus, I'd really need the PWIII with hybrid inverter, for a PV extension, but no idea when that'll reach UK shores, nor at what price.

Thanks for the thread, certainly one for me to lurk, and follow with interest.

[nowty]

The Fogstar blurb says it uses "16 premium LF304 Grade A EVE cells", i.e. the same sort you buy for homebrew systems from China. So I don't see any likely difference in cycle life between that or a Pylontech or most others types of LFP storage. I also like it has a built in heater, 16 cells and its on wheels.

The life of your battery depends more on your use and abuse of it.

[resybaby]

He was probably using cycles as the basis of his advice about longevity.
Fogstars being approx half of the suggestion (because thats all these cycles are) of Pylons.

[wookey]

Has anyone tried/investigated the new pylontech Pelio packs? It's a snazzier-looking form factor and much higher C-rate, but I've not found any info on whether they are as hackable as the pylontechs. Maybe they use exactly the same protocol (that would be sensible, but who knows).
https://en.pylontech.com.cn/products/c23/135.html

I'm planning Fogstar + Victron multiplus II. I was going to go with pylontech before I discovered Fogstar which is both a lot cheaper and a rather more convenient form-factor for my location. My main criterion is openness of system design and no 3rd-party server involvement, hence paying extra for Victron (although it's a lot less extra than when I 1st started looking - prices have been very volatile over the last 2 years). The modularity of their kit is great too.

[Stinsy]

Has anyone tried/investigated the new pylontech Pelio packs? It's a snazzier-looking form factor and much higher C-rate, but I've not found any info on whether they are as hackable as the pylontechs. Maybe they use exactly the same protocol (that would be sensible, but who knows).
https://en.pylontech.com.cn/products/c23/135.html

I'm planning Fogstar + Victron multiplus II. I was going to go with pylontech before I discovered Fogstar which is both a lot cheaper and a rather more convenient form-factor for my location. My main criterion is openness of system design and no 3rd-party server involvement, hence paying extra for Victron (although it's a lot less extra than when I 1st started looking - prices have been very volatile over the last 2 years). The modularity of their kit is great too.

I guess the Pelio is brand new. I've not heard of them bein in-stock at a UK supplier let alone know of anyone with them in and working. I assume the protocol is identical (would be silly to do anything else!).

I have heard of a few "Pylon-Force L2" installations. Seems to be a similar concept...

[nowty]

The spec suggests they are 16 cell LFP and similar price (per kWh) to the standard Pylontech range.

Voltacon have them for sale at £1550 inc VAT per 5.12kWh unit.
https://voltaconsolar.com/pylontech-pel ... proof.html

Likely to be available elsewhere soon.

EDIT - The charge / discharge spec is the same as the US5000's