@upnorthandpersonal Thanks, for my 12v boat system I have been able to set suitable voltages as the chargers are configurable ( the first battery system I fitted  is 11 years old heavily abused but still alive). I don't know if the Solis is configurable, the manual is not very helpful.

@bash Thanks, yes Mine have the JK balancer, they are the ones with the Pace BMS and heating as they are in an unheated conservatory.

Posted by: @upnorthandpersonal

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If a cell should fail down the line for some reason, just replace it. They're well under 80 Euro per cell in single cell quantities..

I agree.

But if you're needing to replace either just one cell, or an entire battery within an array of several, take care!

You can't just slot in a new cell or battery at a SoC which is markedly different to the others.
That would result in large current flows as they try to evenly distribute the charge.

Please ask here first, and we can offer guidance.

Posted by: @transparent

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But if you're needing to replace either just one cell, or an entire battery within an array of several, take care!

You can't just slot in a new cell or battery at a SoC which is markedly different to the others.
That would result in large current flows as they try to evenly distribute the charge.

SoC can be very different, voltage not. Since voltage settles quickly, it's actually very easy to add LFP batteries in parallel to existing arrays of them. Even at different voltages, you may have a short-lasting current spike, but it's not really something that causes too much of a concern: the voltage will quickly drop (just as with a battery under load) and settle at the same voltage as the others. 

This is of course due to the flat curve, something not shared with other lithium chemistries and something I also consider a plus point for LFP.

Posted by: @bash

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(that Fogstar now fit in the current batteries).

DO you know how long this has been fitted or how I find out which one I have fitted?

The Solis app shows the volts the battery is charging at and it is below 55V when the battery shows 100%SOC. On the graphs it also looks like it stops charging as soon as it reaches 100%

Posted by: @bash

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I replaced the Seplos Active balancer to a JK 2A (that Fogstar now fit in the current batteries).

My kit had a Seplos v3 BMS and a JK load balancer. 

Do you mean you replaced both with the JK drift pro? 

@batpred 

No. Mine, as yours, came with the Seplos V3 BMS.

It also came with a Seplos Active balancer, which is rubbish. Fogstar Found that out quite quickly and replaced it with  JK 2A active balancer for future orders, which is what you have.

I asked Fogstar for the same JK active balancer, which they duly sourced and supplied to me, which I fitted a few months ago.

@johnnyb 

They started supplying the Seplos units with the new JK 2A active balancer about 6 months ago.

I bought 3 packs. The last one I bought about 6 months ago came with the JK Active balancer.

If you connect to your balancer (not the BMS) via Bluetooth you'll see if it's the JK balancer.

The Seplos BMS ramps down the charge rate as it approaches full capacity, thus slowly charging the last couple of %, giving plenty of time for the pack to top balance (unless your pack is horribly balanced).

Posted by: @jancold

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I know there are a number of charging periods but had not thought of using them that way. My assumption was that the inverter had automatic charge phases, bulk, absorb, float like a battery charger which information it must get from the BMS or its own current measurement? If an inverter just pumps in say 100A and stops dead on being told battery 100% that is mad.

Mine has a Seplos BMS, but I do not see the charging slowing. When it reaches 100 soc, it stops. Perhaps the slowing only works with some specific BMS setting.

With Seplos, both Jinlong/Solis and Pylontech protocols seem to work with the Solis. I left it with Pylontech. 

@bash has it slowing down, is this using Pylontech? 

Posted by: @bash

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They started supplying the Seplos units with the new JK 2A active balancer about 6 months ago.

I only ordered mine in November so I should be good.

I didn't know I could connect to the battery or the BMS via bluetooth

Posted by: @johnnyb

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I didn't know I could connect to the battery or the BMS via bluetooth

Yes, here's a.mix of Bluetooth and modbus based ones.

@transparent @bash 

It seems the Solis is providing a moving average of power, making it seem that it gradually reduces the power as the battery reaches soc of 100 (orange).

But the same power reading from the seplos bms via Bluetooth shows a very sudden drop (green). In this case, the seplos seems to be right, as I cannot see how a smooth curve could be synthetically transformed into a sudden drop, but the opposite is simple. The temperature curve also supports the same interpretation. 

@batpred

I don't recognise that screenshot you have posted.

I spent many nights working out why the unit's weren't balancing as well as I'd hoped using the Seplos desktop app.

Once the batteries reached around 97-98% capacity the BMS would ask the Solis inverter to ramp down the charge rate, dropping to around 10A, possibly 5A, from the requested 100A charge rate I set 

This slowing of the charge meant the JK balancer had time to top balance the cells before one (or more) ran away and caused an over voltage alarm/cut-off.

I haven't checked for a while as I don't fancy spending another night waiting until 3 or 4 in the morning to observe!

If I get up early one day and it's still charging I'll take a screenshot for you.