Seplos BMS not charging/discharging after cold weather - Resolved 'operator error' DOH!!

[MisterB1959]

It got cold in my area of the UK on saturday and the battery (Seplos BMS) failed to charge overnight - the sunsynk inverter shows fault code F56 - which identifies it as DC Voltage low ..... i assume the cold temp took it below its charging temp and it therefore failed, however its been a couple of days now and the battery is showing at 53% SOC but still doesnt charge and discharge - there's a small trickle discharge of around 21W showing via the app - which was around 54% a day or so ago.

the battery isnt showing any fault codes on the BMS screen and i have tried the reset button on the BMS all to no avail -

can anyone advise as to what the issue might be and how to resolve it please?

 

[SeaGal]

8 degrees is cold, but not that cold. What is the low temp cut off of the Seplos set to?

3.29V is about right for the 53% SOC, so that looks OK.

Temp alone won't have taken battery voltage down.

My guess is Seplos disconnected battery due to low temp setting and it's not got hot enough to reset itself.

Sunsynk then reported low battery voltage as the BMS disconnected it.

That's just my best guess having not got a Sunsynk nor Seplos

 

[Lt.Dan]

I wonder if the temperature reconnect value is 10*C?

Try warming them up a bit? That value can also be changed in the Battery Monitor PC software

 

[MisterB1959]

Thanks both, i have put a heater in the area and ordered a heating pad - i did think (hope) it might be a temperature issue and will take a look in the morning when the heater has had chance to do its job. i will see if i can find where the temp disconnect/reconnect temperatures are and decrease the reconnect if its too high. i assume there needs to be around 5 degrees difference or else it would be on off / on off too frequently ?

 

[SeaGal]

i assume there needs to be around 5 degrees difference or else it would be on off / on off too frequently ?

Yes, of course... the hysteresis will be configurable. My JBD BMS lets you set trigger and release values like this... (temp is CHGUTP = charge under temp protection)

 

[MisterB1959]

I heated the area up and got up to these values



I actually got them up to a higher value (cells were around 14`C, and then reset the battery, but it still won't charge. I am convinced it's a settings issue but can't connect via Bluetooth (prob using the wrong app!) but can connect via laptop but I can't find any option to reset or recalibrate temp restart

 

[MisterB1959]

ok, ive sorted it !!! all working as it should.

The solution ----

my battery disconnect switch had failed - so no power was getting to the inverter, no wonder it wouldnt charge or discharge ......!!!

i found it by being methodical and using my multimeter to test everything .... @SeaGal - you were right (hopefully) the low temp on its own wasnt enough to stop it working, your comment made me start to consider other possibilities, perhaps it might help others who have a similar issue

Signed
Mr Happy as Larry !!!

 

[SeaGal]

Result!

Though it's concerning a battery disconnect switch failed - good it failed completely off and not half-way off with a dangerous resistance ?.

Might be worth getting a more meaty one to replace it? I was impressed with the build quality of my Jean-Muller NH fused disconnector...

Jean Muller Fuse-switch-disconnector KETO size 00 body (battery isolator) - SegenSolar EU

segensolar.eu

 

[MisterB1959]

it was actually my fault, i had removed it from the wall whilst making some changes to cabling layout so it was loose but i had operated it like that, putting unnecessary strain on the switch mechanism. i have a more robust one ready to go as i am increasing cable size and adding an additional battery. i will also be fitting the heat pads externally that came yesterday - though i am really tempted to buy the new fogstar battery and sell my 14.3kw upright seplos 28L .......

 

[SeaGal]

i am really tempted to buy the new fogstar battery and sell my 14.3kw upright seplos 28L

Why? Not much more kWh? Or keep both

 

[MisterB1959]

Why? Not much more kWh? Or keep both

LOL, im actually thinking of getting two of the new ones and selling my current one, there's no problems with it and its only been use for about 5 months or so but as im using them in an unheated area then the newer ones might be the best option for my circumstances. could be a bargain for someone looking for a seplos 280L upright @14.3kw already assembled and guaranteed working ....

 

[SeaGal]

already assembled and guaranteed working

LOL (after the last 2 days)... will you be selling it with @SeaGal's technical support contract? ?‍?

(only kidding, sure it won't hang around for long)!

 

[MisterB1959]

LOL (after the last 2 days)... will you be selling it with @SeaGal's technical support contract? ?‍?

(only kidding, sure it won't hang around for long)!

At £2k for a 5 month old ready assembled 280L with 16 X 280 EVE cells @14.3kw AND your back up, in sure it will be a steal for someone!!

 

[ddonq1412]

There is a seller in the UK that has being selling these boxes for 2k all brand new. Though he is getting from china it's the V3 version.

 

[MisterB1959]

There is a seller in the UK that has being selling these boxes for 2k all brand new. Though he is getting from china it's the V3 version.

That surprises me at that price (though they all come from China), I assume he must be buying by the container and spending a bit of time putting them together. Fogstar sell them for @ £2400 but then you have to top balance the cells and then assemble the battery. It took me well over a week to top balance the cells. Are they Grade A EVE cells ? Do you have a link or name of his site etc? He might have other things I could be tempted by.

My only issue with my Seplos is that I really need it to be heated because it's in an unheated outside utility room. Adding a heater etc now is probably uneconomical. I love the look of the upright Seplos it looks really sleek.

 

[ddonq1412]

There name is Gavin Wallace on Facebook . Company is lynx power Scotland based. The units he is getting is the same as fogstar build your own he does charge extra to balance and build. Really you don't have to balance on V3 as they have active balancer. This mane is getting them by container has been doing it a year since I got one from him and went on to get about 6 units now from him. Support is fantastic the heater pads is for the stackable case not the vertical units

 

[MisterB1959]

There name is Gavin Wallace on Facebook . Company is lynx power Scotland based. The units he is getting is the same as fogstar build your own he does charge extra to balance and build. Really you don't have to balance on V3 as they have active balancer. This mane is getting them by container has been doing it a year since I got one from him and went on to get about 6 units now from him. Support is fantastic the heater pads is for the stackable case not the vertical units

Site Suspended - This site has stepped out for a bit

fully assembled (stackable) £3795 ................ !!!!!!!!!!! and you think that that compares favourable with a 280L case of the same capacity for @£2000 , albeit that its been used for 5 months (prob 6 months by the time im looking to sell it)

as for not top balancing because they have an active balancer .......... my understanding is that the active balancer is best employed to keep the cells in balance AFTER they have been top balanced and is only really needed to be used a couple of times a year, rather than continually, i suspect there are a few thousand batteries out there without active balancers, happily working away because they were top balanced correctly. Heater pads are also available for the 280L case !

the reality is that you clearly happy with both price and service that you paid and receive and thats all that matters! best wishes.

 

[ddonq1412]

Last year I paid around 3300 off him for unit. Wholesale prices have came down alot. Sorry not sure what the digs is about I was suggesting the 2k for a pack was probably about the right price. Top balancing would help the BMS learn at start but no longer essential as many have said on YouTube. Active balancer does not remain on unless configured wrong. It comes on when 1 cell hits 3.4 and starts to push the excess charge to the rest of them.

 

[SeaGal]

albeit that its been used for 5 months

No no no... you say "it's just been run-in sir with one careful owner who only used it for running a few lights and the microwave and a gentle warm-up when used for the oven at weekends" ?

Adding a heater etc now is probably uneconomical.

Uneconomical? Surely only about £50 for some 50mm Celotex, a little heater and and STC-1000? Come on, this is a DIY forum

 

[SeaGal]

Well, I am totally confused... @MisterB1959 said...

At £2k for a 5 month old ready assembled 280L with 16 X 280 EVE cells @14.3kw AND your back up, in sure it will be a steal for someone!!

To which @ddonq1412 replied...

There is a seller in the UK that has being selling these boxes for 2k all brand new.

Which, to me, means you were implying @MisterB1959 is overpriced as you can buy them new at that price...

Then we see that the "seller in the UK" sells the kits for £3495, compared to Fogstar's £2396 and @MisterB1959's honest-used-battery-sales-plc for £2000.

And when he queried your reply you said...

Sorry not sure what the digs is about I was suggesting the 2k for a pack was probably about the right price

Err... no you weren't.... unless I'm having a complete blonde moment and missed something ?‍