Top Balance Charger needed

[jassdhali]

Hi,

Newly acquired a SEPLOS Mason Kit and x16 Grade A EVE LF280K Kit from Fogstar.
Cells all look healthy, build date of Oct 23.
Looking to top balance them, currently stting @ 3.22v (will need to upgrade my voltmeter too )
Can anyone with more experience suggest a decent bench charger for the job.

Thanks for your time

Jass

​

 

[johnb2713]

Hi,

Newly acquired a SEPLOS Mason Kit and x16 Grade A EVE LF280K Kit from Fogstar.
Cells all look healthy, build date of Oct 23.
Looking to top balance them, currently stting @ 3.22v (will need to upgrade my voltmeter too )
Can anyone with more experience suggest a decent bench charger for the job.

Thanks for your time

Jass

​

If theyre all pretty close to 3.22v I wouldnt bother the balancer will balance them up in operation. The other option is to add an active balancer to the system, they do work really well with 4 amps of active balance current.


This unit copes much better with balancing than the Seplos BMS ever did, Seplos BMS used to hold balance between 100mV to 200 mV which is OK but the active balancer is much better at 4mV!



If youre really keen to top balance, invest the money in an active balancer (circa £70 ish) and install that, connect your inverter to charge the batteries, let the active balancer level the system up for you. The active balancer works fine with the Seplos BMS still in use managing charge / discharge levels etc.

 

[Badger]

https://www.amazon.co.uk/LeTkingok-EBC-A40L-Battery-Dischage-Capacity/dp/B0B6V1VXZ4
this is the unit i bought to top bslance the cells you have took mine to 3.6v per cell

 

[Badger]

https://www.ebay.co.uk/itm/16591840...Q_Q7d84eUZ2L1SMn8JEzmmat2GEjDCFUaAs4fEALw_wcB

 

[jassdhali]

Thanks for the replies gents

I'm leaning more towards John's suggestion due to the cost perspective & the fact I can assemble the battery sooner

The next question John, in your opinion whats the best active balancer to go for?
Prefer to buy from UK due to time frame of delivery from overseas.

Thanks again for your time.

 

[johnb2713]

Thanks for the replies gents

Youre welcome, were here to help and put the world right

I'm leaning more towards John's suggestion due to the cost perspective & the fact I can assemble the battery sooner

You also have the advantage of the active balancer keeping your batteries perfectly balanced on a continuous basis

The next question John, in your opinion whats the best active balancer to go for?

I chose the NEEY active balancer following on an Offgrid Garage review.

Prefer to buy from UK due to time frame of delivery from overseas.

This is where you come unstuck, I cant find anywhere to get an active balancer from in the UK. That said Aliexpress and Alibaba do guaranteed max 14 day deliveries. My last 10 or so orders with aliexpress have been here in 5 days so not too bad. You can be building your battery, the balancer can be connected later when it arrives, easy connect up, 1 wire to negative and then a wire to each +ve cell terminal, 17 in total.

Thanks again for your time.

No problem, do keep us updated and photos of your build would be nice to see.

 

[Badger]

Thanks for the replies gents

I'm leaning more towards John's suggestion due to the cost perspective & the fact I can assemble the battery sooner

The next question John, in your opinion whats the best active balancer to go for?
Prefer to buy from UK due to time frame of delivery from overseas.

Thanks again for your time.

the only problem is the seplos cells should be nearer to 3.6v to get a full capacity charge not the 3.22v they are supplied only half full of capacity when delivered

 

[johnb2713]

the only problem is the seplos cells should be nearer to 3.6v to get a full capacity charge not the 3.22v they are supplied only half full of capacity when delivered

Why is that a problem? Theyre not Seplos cells BTW theyre EVE cells.

The SEPLOS BMS needs to see a full charge to 100% and then a full discharge to calibrate, it may as well be done at the same time the unit is commissioned. The whole thing about so called top balancing was pre the days of active balancing and really isnt needed now. As long as the cells are somewhere near they will balance fine in a very short space of time.

 

[jassdhali]

This is where you come unstuck, I cant find anywhere to get an active balancer from in the UK. That said Aliexpress and Alibaba do guaranteed max 14 day deliveries. My last 10 or so orders with aliexpress have been here in 5 days so not too bad. You can be building your battery, the balancer can be connected later when it arrives, easy connect up, 1 wire to negative and then a wire to each +ve cell terminal, 17 in total.

I took the plunge
Neey Official store - £60.94 (incl £10.00 For HMRC) delivery 21 Feb

 

[johnb2713]

I took the plunge
Neey Official store - £60.94 (incl £10.00 For HMRC) delivery 21 Feb

I'm sure you'll be fine, it works incredibly well, fit it - set the voltages - click run and forget it.

 

[jassdhali]

Well the Neeeey Active Balancer is here lol, quicker than sending a first class letter

The one thing I hadn't done is take the Seplos case apart, so did so at the weekend.
Guess what, inside appears to be an active balancer too,



Bar that I have a picture of the BMS: (excuse that hairy knee)



So referencing Off Grid Garage, looks like a Seplos Active Balancer.
But the BMS doesn't compare to the videos Andy has up of the in relation to v10 & v11
As the cross connects (shunts?) are in different places & there seems to be more of them.

Any views/experience appreciated.

Will have a better idea when I put it all together, probably towards the end of the month.

Thanks

Jass

 

[johnb2713]

Well the Neeeey Active Balancer is here lol, quicker than sending a first class letter

The one thing I hadn't done is take the Seplos case apart, so did so at the weekend.
Guess what, inside appears to be an active balancer too,

View attachment 16651

Bar that I have a picture of the BMS: (excuse that hairy knee)

View attachment 16652

So referencing Off Grid Garage, looks like a Seplos Active Balancer.
But the BMS doesn't compare to the videos Andy has up of the in relation to v10 & v11
As the cross connects (shunts?) are in different places & there seems to be more of them.

Any views/experience appreciated.

Will have a better idea when I put it all together, probably towards the end of the month.

Thanks

Jass

Not the same as mine....




What does the spec say with regard to balancing? mine is only passive and around 120mA which is useless. Looking at your PCB if it was an active balancer it would have a lot if beefy capacitors and I dont see any?

 

[jassdhali]

John,

looking on the Seplos web site, shows - Seplos 2A Active Balance Board For LFP LiFePO4 Lithium Energy Storage Battery Management Monitoring

https://www.seplos.com/seplos-2a-ac...gy-storage-battery-management-monitoring.html

 

[johnb2713]

John,

looking on the Seplos web site, shows - Seplos 2A Active Balance Board For LFP LiFePO4 Lithium Energy Storage Battery Management Monitoring

https://www.seplos.com/seplos-2a-ac...gy-storage-battery-management-monitoring.html

Sounds good, maybe no need for the Neey one?

I've just had a look at the Seplos link, it doesnt work like the Neey one does. The Seplos unit starts feeding 2 amps to the cells below the balance voltage. The Neey one takes current from the highest cell to charge super capacitors and then discharges that energy into the cell with the lowest voltage. The Neey one is working from both ends of the cell voltage range.

 

[jassdhali]

I've just had a look at the Seplos link, it doesnt work like the Neey one does. The Seplos unit starts feeding 2 amps to the cells below the balance voltage. The Neey one takes current from the highest cell to charge super capacitors and then discharges that energy into the cell with the lowest voltage. The Neey one is working from both ends of the cell voltage range.

Put like that the Neey unit sounds more efficient

 

[johnb2713]

Put like that the Neey unit sounds more efficient

I believe that the Neey one will be better, it's 4 amps as opposed to 2 amps and it's lowering the voltage on the high cell and raising the voltage on the lower ones. I feel it will keep a much tighter grip on the balance. Looking at the Seplos board, it looks like theres 16 relays, one for each cell, the Neey unit is completely solid state, no relays to burn up etc.

 

[jassdhali]

I believe that the Neey one will be better, it's 4 amps as opposed to 2 amps and it's lowering the voltage on the high cell and raising the voltage on the lower ones. I feel it will keep a much tighter grip on the balance. Looking at the Seplos board, it looks like theres 16 relays, one for each cell, the Neey unit is completely solid state, no relays to burn up etc.

John, have built the box completely just to make sure it all works, will now remove the Seplos active balancer & add the NEEY.

The only trouble I am having on this particular step is getting a copy of NEEY app.
Also having issues finding a copy of BMS Studio, cant find it anywhere on Seplos site, keeps showing the actual BMS components.
I have purchased a cable from Fogstar, just getting one of the kids old laptops as mine is only a desktop

Any help greatly appreciated.

Thanks

Jass

 

[jassdhali]

Hi,

Think I may have found them

Will try at the weekend.

Thanks

Jass