BMS and Balancer

If you connect several cells in series, you definitely want a BMS. If not for optimisation purposes then for sure for safety and peace of mind. A BMS controls and monitors your whole battery on cell level niveau, disconnects the whole battery in case of over or under voltage and prolongs the life of your precious battery. An active balancer just balances your batteries, shovels energy from a cell with higher voltage to one with lower voltage. Over time, your pack will be perfectly balanced.
Here is a selection of tested Battery Management Systems and Balancer to use for your LiFePo4 battery cells.

JK BMS with integrated active Balancer
This is the BMS we have all waited for. It’s the Jack of all trades, the ultimate BMS AND balancer combined in one device, controlled with one app.
The video with the first setup, comprehensive review and practice test is here. Wow, I’m impressed with this BMS and it has my full recommendation.

There is now a new version of the BMS available which can be equipped with a screen and power switch. With that function, you don’t need the weird +5V start voltage procedure applied to the BMS any more. Just press the button on the display and it starts. The link below is for the new BMS with this function already.

There is also another method which @Milan shared on my channel:
“… install a pushbutton switch on the connector for LCD pin 1 and 2 (pin 1 is on the left side). Hold for 1 sec and the BMS will switch on. If the button is held for 5 sec, the BMS will switch off.”

BMS for 4s-24s batteries, 200A constant current, 2A active balancer, heating port, CAN and RS-485 comms, display.
AliExpress product link (4s-8s) NEW!
AliExpress product link (8s-24s)

Watch the comprehensive test of the 4s model of this amazing BMS here on YouTube.

BMS communication adapter and tutorial.

JK BMS manual including wiring diagram for booster. (PDF, 1MB)

The app can be downloaded here for both Android and iOS:

250A JBD Smart BMS 4S LiFePO4 with active balancer
Probably the best 4s BMS out in the market right now. This custom build JBD BMS comes exclusively from Muller Energy in Sydney and has a 5A active balancer. Yes, that’s right, a 5A active balancer!
– 250A continues current
– 5A active balancer
– massive aluminium cooler
– copper busbars with M8 bolts
– touch display
– heating function
– bluetooth module
– wiring harness

Take 5% off the product price until 24. Dec. 2022 by using the discount code OGGA
Muller Energy product link (worldwide shipping)
BMS instructions and manual (PDF)

Link to newest Xiao Xiang App

Product video, review and comprehensive test:

HELTEC Smart BMS 50A – 200A
What can I say? The HELTEC Smart BMS feels a bit outdated with no real outstanding features. It is a basic protection board with a beginner friendly app and connection. View the video review here.
– 3s – 25s, 50A – 200A
– 120mA balance current
– iOS and Android smart app version
It comes with a display, RS-485 or CAN and Bluetooth communication.
AliExpress product link

BMS communication adapter and tutorial.

8s LiFePO4 SMART BMS 200A with 2A Active Balancer
This BMS is very similar to the JK BMS above and made for 24V systems. It does not need a booster or power supply as it runs directly from the battery. I have not tested this BMS yet but it uses the same great Bluetooth app and it’s an alternative for 24V systems (8s LiFePO4 battery packs)

AliExpress product link (8s LiFePO4 Smart BMS, 200A, 2A active balancing)

QUCC has got a new version of the Relay-BMS. I must say it’s not as pretty as the old version I have but it’s not a beauty contest, so… yeah The Relay is back!
For both Li-ion and LiFePO4 cells from 13s-20s configuration. It still has 200A permanent and 600W peak current.
Bluetooth is included and you can now also program the sleep time when the relay falls off again (as per manufacturer information, mine does not have this function).
QUCC has a very good customer service (they replaced my faulty BMS in no time) and replies to enquires on AliExpress within minutes.

Common port LiFePO4 and Li-ion Smart BMS with Bluetooth function and app support:
200A with relay: AliExpress product link
150A. 4-8S: AliExpress product link
80A-120A 13-15S: AliExpress product link
30A-100A 16-20S: AliExpress product link

Spare relay 500A 12V/24V: AliExpress product link

Separate port BMS with 2 relays and display, Bluetooth and app support, 300A
AliExpress product link for 3s-8s Li-ion and LiFePO4
AliExpress product link for 12s-16s Li-ion and LiFePO4

Link to newest Xiao Xiang App for QUCC and other BMS’s.

JBD Smart BMS 12V 4S Lifepo4 100A
I tested several JBD “Jabada” BMS recently and found a major problem with the temperature disconnect function. It does not disconnect the load/charger if the current is under the threshold. You can keep charging or discharging the battery in cold/hot weather and potentially damaging your battery. I had a discussion with Will Prowse about this and he talked to several battery cell manufacturers, and it is OK charging cells with small currents even under 0°C.

4S 80-150A: AliExpress product link
4S, 200A with battery heating function: AliExpress product link
7-21S, 200-300A: AliExpress product link

BMS communication adapter and tutorial.

Seems like the ‘Jabada’ BMS are very popular. You need to turn off ‘Charge Balance’ though to make balancing working. With charge balance on (default setting), it will take a very long time to balance your cells, if it works at all…
Watch the full video review here.

If you want an industry leading BMS with great communication options to all major inverters, the SEPLOS Smart BMS is the one. It comes with a nice display which gives you all information you need. CAN and RS485 ports are there for communicating to other batteries but also to your Solar system, like the Victron Venus OS.
I’m still testing all the features and functions and so far I have mixed results. Watch the comprehensive video review here:

– 24V or 48V
– 100A, 150A or 200A
AliExpress product link
Alibaba product link (manufacturer link)

Seplos BMS Function Switch Description (PDF-Link)
Seplos BMS Manuals (Seplos Googe Drive)
Seplos Android App 1.0.24 (for iOS, search for EN BMS in the Apple store)
Seplos V16 Bluetooth Installation guide (PDF)

Daly Smart BMS
OK’ish BMS with a lot of features (extra features access through a PC only). I’m still a bit disappointed with Daly using such a weird method to balance the cells. This option can not be changed as in the JBD BMS. Charge Balance is outdated, old-school and doe snot work well with high capacity cells. The JK BMS above is far superior with its app, features and balance method.
See the full video review here.

And, we found out how the Daly BMS works and balances.
Watch the video here.

BMS communication adapter and tutorial.

3s – 24s Li-ion and LiFepO4 BMS from 80A up to 500A:
AliExpress product link

Daly Li-ion/LiFePO4 Smart Active Balancer
– 3s to 24S
– 1A active balance current
– smartphone, PC access
– set individual balance on/off voltages as per your needs

AliExpress product link

Active Balancer Equalizer 1A
– 3s to 10s
– for Li-ion, Lifepo4, LTO batteries
– 1A active balance current
– fixed turn on voltage at 3.3V

AliExpress product link

NEEY – 4A Active Smart Balancer with Bluetooth
The NEEEEEEEEY is back. And it’s good. Better, stronger and fully working. The popular active smart balancer is now working as expected. It is fully fixed as per our feedback. They have listened and all functions are now as they should be. The device is fully programmable and works perfectly. It’s the best smart balancer on the market so far.

This active balancer can be programmed via Bluetooth app to your needs. Deviation, sleep voltage, balance current… It balances with 4A at any point of time, regardless the voltage difference between the cells. The active balancer can work with all batteries from 2s to 24s batteries configuration.

AliExpress product link
Amazon product link

App download (NEEY Github website)

3S – 21S Balancer

Active Equalizer Balancer
I have used these balancers for testing and they are working great. Even with the big capacity cells, they don’t have a problem as they can transfer up to 5A from one cell to another.
I’ve done some testing with these balancers and show this in the video here and here. They really pushed close to 5A across the cells even at lower voltage difference of only 0.7V.
You can order them from 3S up to 21S and they work with all sort of batteries together: Li-ion, LFP and LTO.
AliExpress product link 3s-21s active balancer, 5A balance current

HELTEC Active Equalizer Balancer
– 3s-24s, 5A
AliExpress product link

Heltec 10A active Balancer
You can watch the full test here in this video. I’m not so sure why this device actually exists…
– 4s – 8s
– 10A balance current
– transformer energy transfer
AliExpress product link

All links on this page are affiliate links to support the channel. I’m getting paid a small commission if you order products or services through these links. This does not make the products or services more expensive for you.

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