Tim Serong

For those who've been following the saga of our solar PV & battery storage system, the latest news is that I decommissioned our last Redflow ZCell a week ago in order to have two stacks of three Pylontech Pelio batteries (https://en.pylontech.com.cn/products/Pelio) installed. As described in my last blog post (https://ourobengr.com/2025/12/what-happened-next/) I'd pushed the failing ZCells as far - or possibly further - than could reasonably be expected. These new batteries work just fine with our existing Victron inverter/charger gear, and give us just under 30kWh of usable storage capacity. I'll do a proper writeup in due course once they've got a few more miles on them, but for now here's a picture.

#solar #energystorage #redflow #pylontech #victron

Feb 21 at 6:26amWeb
Show threadraweFeb 21
@tserong after some wrong 3 AM "nuclear meltdown" alarms from my Pylontech US2000Cs I recommend to watch out for firmware updates for Pylontech products. (They work 24/7 without issues now for years)
Show threadTim SerongFeb 21
@stereo4x4 thanks for the tip 🙂
Show threadAndrew ElwellFeb 21
@tserong ooft. It's a shame the whole flow thing failed, it did seem a nicer tech than the 'big box of firey metal'. On the plus side that's a sizable increase in capacity for you?
Show threadTim SerongFeb 22
@Elwell yeah, a single ZCell is 10kWh, but you can do 100% depth of discharge. A single Pelio is 5.12kWh with allegedly up to 95% DoD, but I vaguely recall reading somewhere that they're happier in general if you don't drop 'em below 20% SoC, although I can't find that now, so I might be wrong. Anyway let's pretend I didn't want to do more than 80% DoD, with 6 units that gives us 24kWh to play with, which is ample to have some charge in the battery at all times in case of power outage, plus some that gets charged up every day and drawn down every night. We hit 100% SoC for the first time at about 16:00 yesterday, and between then and now >checks notes< we've generated 18.9kWh of solar, our loads have consumed 28.9kWh and we've pulled just under 1kWh from the grid, which may as well be nothing ;-)
Show threadAndrew ElwellFeb 22
@tserong Nice. We only have 10kWh to play with. Depending on the weather we're normally recharged by lunchtime. I haven't seen anything in Sonnen's docs with a predicted capcity remaining after 5 / 10 yrs and ours gets cycled down to ~20% overnight in summer, fully down in winter (with an off-peak second cycle before peak rate kicks in in the morning)
Show threadTim SerongFeb 23
@Elwell cool, sounds like its working well.