@batpred 

As my battery packs were heavily used yesterday and had discharged to 20%, the charge window would mean they'd hit capacity around 6.30am so I decided to take a look at my packs this morning.

The conclusion.

As Andy and I have said, the Seplos BMS will ramp down the charge rate when nearing capacity (about 98.5-99%).

The issue is how quickly the charge rate ramps down to keep up with the cells now starting to race away (around 3.430V).

My full capacity target is 3.450V.

This is very very close to 100% fully charged. I am not chasing a tiny bit extra.

With aiming to be fully charged at 3.450V (55.20V total capacity )and the JK Balancer set to start balancing at 3.450V there is a small window to start balancing and the Seplos BMS to ramp down it's charge rate. If your cells aren't as well balanced as mine you may have even less time).

I observed about 5-10 minutes.

At this point the total pack voltage hit 55.20V, the BMS resets to 100% and shuts down the charge request.

Am I happy with this.

Yes and no.

My packs were top balanced at 3.600V and are still well balanced (15mV at 55.20V pack voltage), so they don't require much balancing.

However 5-10 minutes isn't a lot of time (plus a bit extra as they taper down when the charge current is stopped).

With this in mind I have set my balance start voltage to 3.410V which will give me about 30 minutes of balance time and should ensure they stay balanced at 3.450V (55.2V total pack), my target 100% full capacity.

As a side note I observed the the charge/discharge time window is 10 minutes out of sync.

My Inverter is set to charge between 12.10am and 6.50am to ensure I don't use any peak electricity during charging.

My packs started discharging at exactly 6.40am.

With this mind I have adjusted the heavy draw items (garage heater, EV charger etc) to stop at 6.40am to ensure they aren't discharging from the battery packs and reducing their capacity unnecessarily.

Posted by: @bash

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As my battery packs were heavily used yesterday and had discharged to 20%, the charge window would mean they'd hit capacity around 6.30am so I decided to take a look at my packs this morning.

The conclusion.

As Andy and I have said, the Seplos BMS will ramp down the charge rate when nearing capacity (about 98.5-99%).

Thanks for checking and sharing! 

It is odd that Fogstar advised differently, so either:

• they do not know how the Seplos BMS works 
• they know, but prefer to close a query about how the Seplos BMS works by stating it does not do this, as they do not care enough

Some of their current battery kits use BMS from other manufacturers. 

I am still planning to get my JK balancer to work.

@batpred 

I'd change your JK balance start voltage a little lower to give a it a chance to actually balance your cells.

@batpred 

The Pace BMS also isn't the best with it's balancing algorithm, along with most other BMS manufacturers.

Only JK seem to have a handle on this and are regarded as the best in the industry.

Which is why ,I assume,Fogstar fit the JK balancer to their 16Kw Pace BMS batteries?

Posted by: @bash

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@batpred 

I'd change your JK balance start voltage a little lower to give a it a chance to actually balance your cells.

Yes, but I need to reopen the battery box.. I just noticed that the binary_sensor.503010d0243_problem "sensor" (on the JK HA integration) reports a problem. No details provided, so the first thing will be to recheck the cabling.