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Ok, so i have given all cells a nice test which took 4 days - Constant Current 40A discharge to 2.80V then CV to 3.55V max 40A with tail current of 0.20A. - then physically parallel the 4 cells, with supplied flexible busbars, and a slow manual top balance CV charge to 3.65V at max 5A with a...

Wow, Here is the link to the youtube video I think you are talking about. Amazing. Thanks. This might actually be sensible for me, as it means I can mount them nicely in a wooden box in the boat without changing the existing (Winston) cell connection straps. Thanks a lot ! Cells are...

Steady 25-35 C in the tropics, nothing more than that.

I think the flaw in my logic was that consecutive batteries on the production line would have similar performance, and therefore would be matched. So this actually suggests that to buy direct from Winston is a mistake, unless they provide test information, or a matching service. Back when I...

Here are some graphs showing longer term usage profile - the peaks and troughs are a bit flattened here, more detailed below. And the rainy month of September, where we have patches of sunny days and patches of cloudy days .... This shows better than I explained how overcharge is unlikely...

Whilst on the land, the cells have enjoyed 1900W of Solar, so they are certainly getting a daily workout. 140A from 2x Victron SmartSolar, less house loads. And we recently started using electric hob, etc which we use more often when solar is available. The inverter was a Victron MultiPlus...

These batteries have had their 2.5 years on land, driving a MultiPlus 3k inverter. I have taken delivery of a shiny new GobelPower GP-SR1-PC200 14.3kWh 48V battery and an 8k Quattro so we can make bread any time the day or night. I will run that on a VERY modest setting. The Winston's will go...

Edit 1: Yes, I can see from this graph that the highest cell was held at 3.50V for the whole afternoon, and yet the lowest cell never balanced up. The system is totally solar, and in the tropics, so the solar turns off around 5.30pm Edit 2: I would have to say that this is a very unusual...

Only 500 cycles according to REC BMS. They were on a boat for first few years, before we moved them to the land where they would have regular daily cycles.

These batteries have rarely seen voltage above 3.55V; I set REC-BMS to balance above 3.45V and charge completion at 3.50-3.55V. I occasionally push up the Max Charge Voltage to 3.65V for a single balance cycles (using solar) and then restore it afterwards. I keep screen grabs in a Telegram chat...

I was of a similar mind to OP; but then my Winstons (of 4 years) have started to fade, and very very fast. I have seen another comment from a few years back that one cell let down the pack, and I have had a similar experience. Last week, I emailed my sales contact on...

I made a 12V battery from 4x Winston 700Ah cells. Been managed by REC-BMS with Active Balancer for 4 years. Raspberry Pi + Victron. The cells were new direct from China factory with consecutive serial numbers. You might call them A Grade these days, this was the way they did cell matching...