|
|
Li-Ion BMS options
A comparison of commercially available Li-Ion BMSs
These tables compare Li-Ion BMSs available on the market today.
This information does not constitute an endorsement of any of these companies and products.
While the information presented here is believed to be accurate, Elithion takes no responsibility for any errors.
Please send us comments, corrections and additions.
Go to the Parametric BMS selector utility.
This table explains the difference between digital and analog BMSs, and between Protectors, Balancers, Monitors, Displays and Regulators.
|
| Reports individual cell voltages
| Balances the battery
| Requests that battery be switched off
| Includes switch to turn off battery
|
Digital:
knows where
the problem is
and by how much
| Protector
| ✓
| ✓
| ✓
| ✓
|
| Balancer
| ✓
| ✓
| ✓
|
|
| Monitor
| ✓
|
| ✓
|
|
| Meter
| ✓
|
|
|
|
Analog:
knows there's
a problem,
but doesn't know
where and
by how much
| Protector
|
| ✓
| ✓
| ✓
|
| Balancer
|
| ✓
| ✓
|
|
| Monitor
|
|
| ✓
|
|
| Regulator
|
| ✓
|
|
|
Digital Protectors and Balancers
Note: log scales. Sources: (15)
Protectors (thin line), Balancers (thick line).
Note: log scales. Sources: (15)
Sophisticated digital technology, able to measure and report every cell voltage, to balance the battery pack, and to cut-off the battery current.
To see additional information, hover your cursor over the  icons.
Company
(1)
| Picture
(2)
| Model
| Topology
(3)
| No of cells
(4)
| Cell shape
(5)
| Current
| Temper.
(7)
| Curr.
sense
(8)
| "Fuel
gauge"
(9)
| Comm.
(10)
| Fan
drive
(11)
| Displ.
(13)
| Case
(14)
|
All New Energy
Distributed by Lithium Batteries Australia (LBA) / Battery Manufacturer's International (BMI) / LifeBatt
Taiwan
| 
| VMS / GBTS
| Non-distributed,
Modular
| 1~24
| Any
|
| ✓
| -
| -
| Wire
serial
| -
| -
| -
|
Chargery
China
GuangDong
| 
| B series
| Non-distributed,
Centralized
| 1~12
| Any
|
| -
| -
| -
| -
| -
| ✓
| Metal
|
Clayton power
UK
| 
| 'C' and 'CF'series
| Non-distributed,
Centralized
| 4, 8, 12, 15, 19 or 23
| Any
| 125 to 300 A cont.;
800 to 100 A peak
| ✓
| ✓
incl.
| ✓
| CAN
RS232
Wire
| -
| Incl.
| Metal
|
e-chip
China
Hong Kong
| 
| BMS-xxS-xxxA
| Non-distributed,
Centralized
| 4,8,13,16,26
| Any
| 100 A
| ✓
| ✓
| -
| CAN
| -
| Optional
| Metal
|
Lithium Balance
Birger Carlsen
Denmark
| 
| iBMS
| Non-distributed,
Centralized
| 15, 19 or 23
| Any
| 140 A to 250 A cont.
600 A peak
| ✓
| ✓
incl.
| ✓
| Wire /
simplex
RS232
| -
| -
| Metal
|
Lithium Start
Thomas Cook
US - CA
San Francisco
| 
| BluFlex
| Distributed
| 4
| Any
|
| ✓
| -
| -
| -
| -
| -
| -
|
Ventec
France
|
| iBMS
for electric bicycles
| Non-distributed,
Master/slave
| 10
| Any
| 50 A
| ✓
| ✓
| ✓
| CAN
RS232
| -
| -
| -
|
iBMS
for scooters
| 18
| 350 A
| ✓
| ✓
| ✓
| CAN
| -
| -
| -
|
Company
(1)
| Picture
(2)
| Model
| Topology
(3)
| No of cells
(4)
| Cell shape
(5)
| Current
| Temper.
(7)
| Curr.
sense
(8)
| "Fuel
gauge"
(9)
| Comm.
(10)
| Fan
drive
(11)
| Displ.
(13)
| Case
(14)
|
Sophisticated digital technology, able to measure and report every cell voltage, to calculate SOC, to balance the battery pack, and to request that the battery current be shut off to protect it.
Does not include a switch to cut off the battery current.
Note: log scales. Sources: (15)
To see additional information, hover your cursor over the icons.
Company
(1)
| Picture
(2)
| Model
| Topology
(3)
| No of cells
(4)
| Cell shape
(5)
| Balance
current
| Temper.
(7)
| Curr.
sense
(8)
| "Fuel
gauge"
(9)
| Isol. detect
| Comm.
(10)
| Fan
drive
(11)
| Contac.
drive
(12)
| Displ.
(13)
| Case
(14)
|
123 Electric
The Netherlands
∝
| 
| 123 BMS
| Distributed
| 1~255
| Prismatic
| 1 A
| ✓
| ✓
| ✓
| -
| USB
| -
| -
| -
| -
|
BatteryMan
Germany
| 
| iBM
| Distributed
| Any
| Any
| 0.01 A
| ✓
| ✓
| ✓
| -
| -
| -
| -
| -
| -
|
Black Sheep Technology
Ron Anderson
US
No. Carolina
| 
| Stack V1
| Non-distributed,
Modular
| 1~32
| Any
| ✓
| ✓
| ✓
| ✓
| -
| Serial
| ✓
| ✓
| ✓
| -
|
| Cage V2
| Non-distributed,
Centralized
| 1~48
| ✓
| ✓
| ✓
| -
| Serial
| ✓
| ✓
| ✓
|
| Mini V3
| Non-distributed,
Master/slave
| Any
| ✓
| ✓
| ✓
| -
| Serial
| ✓
| ✓
| ✓
|
| BMS Auto V4
| Non-distributed,
Master/slave
| Any
| ✓
| ✓
| ✓
| -
| Serial
| ✓
| ✓
| ✓
| Automotive
grade
|
Clayton power
UK
| 
| -
| Non-distributed,
Master/slave
| up to 496
| Any
| 1.5 A
| ✓
| ✓
| ✓
| -
| ?
| -
| -
| -
| Plastic
|
Convert the future
Mark Hardy
US
CA
| 
| Flex BMS48
| Non-distributed,
Centralized
| 48
| Any
| ✓
| ✓
| ✓
| ✓
| -
| Internal Bus
| ✓
| -
| ✓
| Plastic
|
| Flex BMS84
| Non-distributed,
Centralized
| 84
| Any
| ✓
| ✓
| ✓
| ✓
| -
| Internal Bus
| ✓
| -
| ✓
| Plastic
|
Elektromotus
Gintautas Paluckas
Lithuania
| 
| EMUS BMS
| Distributed
| 4~256
| Prismatic
| 1.3 A
| ✓
| ✓
| ✓
| -
| Wire
CAN
USB
RS232
| ✓
| -
| Avail.
GUI
| Metal
|
Company
(1)
| Picture
(2)
| Model
| Topology
(3)
| No of cells
(4)
| Cell shape
(5)
| Balance
current
| Temper.
(7)
| Curr.
sense
(8)
| "Fuel
gauge"
(9)
| Isol. detect
| Comm.
(10)
| Fan
drive
(11)
| Contac.
drive
(12)
| Displ.
(13)
| Case
(14)
|
Elithion
Davide Andrea
US
Colorado
| 
| Lithiumate™ Pro
| Distributed
| 2~255
| Sml cyl
Lrg cyl
Prism.
Pouch
| 0.2 A /
3 A
| ✓
| ✓
| ✓
| ✓
| Wire
CAN
RS232
| ✓
| ✓
| Avail.
GUI
| Metal
|
| Lithiumate™ Lite
| Distributed
| 2~200
| Prismatic
| 0.2 A /
3 A
| ✓
| ✓
| ✓
| -
| Wire
USB
| -
| -
| Avail.
GUI
| Plastic
|
| Lithiumotive™
Not yet released
| Distributed or non-distributed
| 1~65535
| Any
| 0.1 A /
3 A
| ✓
| 1000 A
| ✓
| ✓
| Wire
CAN
USB
| ✓
| ✓
| GUI
| Sealed composite
|
Evaira
US
California
| 
| CellSpy
| Non-distributed,
Master/slave
| 224
| Any
| ✓
| ✓
| ✓
| ✓
| -
| CAN
RS232
Ethernet
| -
| -
| -
| Metal, sealed
|
| International Rectifiers' EMS
| Non-distributed,
Master/slave
| 200 max
| Any
| 0.2 A
| ✓
| ✓
| ✓
| -
| CAN
RS232
Ethernet
| -
| -
| -
| -
|
EVLithium
(Norway)
Ronny Titternes
(Not to be confused by the Chinese reseller by the same name.)
| 
| EV Mini BMS
| Distributed
| 1~400
| Prismatic
| 0.25 to 1 A
| -
| -
| -
| -
| RS232
Wire
| -
| -
| -
| -
|
EVPST
China
Guangzhou
| 
| BMS-4
| Non-distributed,
Master/slave
| ???
| Any
| ✓
| ✓
| ✓
| ✓
| -
| CAN
RS485
| -
| -
| ✓
| Metal
|
Ewert Energy Systems
Chris Ewer
US
Illinois
| 
| Orion™
| Non-distributed,
Centralized
| 1~180
| Any
| ✓
| ✓
| ✓
| ✓
| ✓
| Wire
CAN
| ✓
| -
| GUI
| Metal
|
Flux Power
Escondido CA
USA
| 
| no name
| Non-distributed,
Master/slave
| 1024
| Any
| 1 A
| ✓
| -
| -
| -
| CAN
| -
| -
| ✓
| Sealed metal
|
GfE/GK-Anlagentechnik
Germany
EU
| 
| none
| Distributed
| 16
| 100 Ah prismatic
| ✓
| ✓
| ✓
| ✓
| -
| -
| -
| ✓
| ✓
| -
|
GWL Power
Guernsey
Channel islands
EU
| 
| RT-BMS
| Non-distributed,
Master/slave
| 192
| Any
| ✓
| ✓
| ✓
| ✓
| -
| CAN
RS232
USB
| -
| ✓
| ✓
| Plastic
|
Jon Elis
Lithuania
EU
∝
| 
| BMS ver.2
| Distributed
| 254
| Prismatic
| ✓ 2 A
| ✓
| ✓
| ✓
| -
| CAN
USB
Bluetooth
| -
| ✓
| -
| -
|
Company
(1)
| Picture
(2)
| Model
| Topology
(3)
| No of cells
(4)
| Cell shape
(5)
| Balance
current
| Temper.
(7)
| Curr.
sense
(8)
| "Fuel
gauge"
(9)
| Isol. detect
| Comm.
(10)
| Fan
drive
(11)
| Contac.
drive
(12)
| Displ.
(13)
| Case
(14)
|
I + ME ACTIA
Germany
| 
| IME
| Non-distributed,
Master/slave
| 140 max
| Any
| ✓
| ✓
| ✓
| ✓
| -
| CAN
RS232
| -
| -
| -
| -
|
Leoyun New Energy
China
Resold by EVlithium (China)
| 
| LY-CS
| Centralized
| 6~24
| Any
| 0.5 A
| ✓
| ✓
| ✓
| -
| RS232
| -
| -
| ✓
| Metal
|
Ligoo
Anhui Wicom New Energy Technology
China
Rebranded by Richard Edminston / RCEV products / Pensacola FLA (no website)
Resold by Electric Car Company as HiPower BMS or LIGOO BMS
Resold by Electway as AUTO_EMS_V3.0 BMS
Resold by EVlithium (China)
| 
| AUTO_EMS_2.0
EHUG BMS
LIGOO BMS
EK30
| Non-distributed,
Master/slave
| 5~104
| Any
| ✓
| ✓
| ✓
| ✓
|
| CAN
RS485
USB
|
|
| ✓
| Metal
|
| EK-FT-11
| 12 max
| Any
| ✓
| ✓
| ✓
| ✓
|
| CAN
RS485
|
|
| ✓
| Metal
|
| EK-FT-12
| 16 max
|
| EK-FT-21
| 25 max
|
| EK-YT-21
| 24 max
|
| YD-UP-21
| 12~16
|
|
|
|
|
|
|
|
|
| Metal
|
|
| MT-JS-11
| ?
|
MT-JS-21
| ?
|
ES-DY-13
| ?
|
Lithium Balance
Birger Carlsen
Denmark
| 
| sBMS
| Non-distributed,
Master/slave
| 256
| Any
| ✓
| ✓
| ✓
| ✓
| -
| CAN
wire
| -
| -
| -
| Sealed metal
|
Manzanita Micro
Rich Rudman
US
Washington
| 
| MK3x4SMT
| Non-distributed,
Master/slave
| Any
| Any
| ✓
| ✓
| -
| -
| -
| Wire
| -
| -
| -
| -
|
Methods
Patrick Schindler
US
California
| 
| LTC BMS
| Non-distributed,
Centralized
| 36
| Any
| ✓
| ✓
| ✓
| ✓
| -
| Wire
USB
| -
| -
| -
| Aluminum
|
Millen Works
Rod Millen
US
California
| 
| -
| Non-distributed,
Master/slave
| 192
| Any
| 0.7 A
| ✓
|
|
|
| CAN
| -
| -
| -
| Plastic
|
Company
(1)
| Picture
(2)
| Model
| Topology
(3)
| No of cells
(4)
| Cell shape
(5)
| Balance
current
| Temper.
(7)
| Curr.
sense
(8)
| "Fuel
gauge"
(9)
| Isol. detect
| Comm.
(10)
| Fan
drive
(11)
| Contac.
drive
(12)
| Displ.
(13)
| Case
(14)
|
Pacific EV
Cory Cross
US
Washington
| 
| TBMS
| Distributed
| 1~?
| Prismatic
| ✓
| ✓
| -
| -
| -
| Wire
| -
| -
| -
| -
|
Peter Perkins
UK
| 
| V series
| Distributed or
Non-distributed,
Master/slave
| 1~255
| Prismatic
| ✓
| ✓
| ✓
| ✓
| -
| Wire
RS232
| -
| -
| Included
| -
|
REC
Slovenia
EU
| 
| BMS 7
| Master/Slave
| 210
| Any
| 1.3 A
| ✓
| ✓:
380 A
| ✓
| -
| CAN, RS485
| ✓
| ✓
| GUI
| Metal
|
Tritium
David Finn
Queensland
Australia
| 
| IQcell
| Distributed
| 256
| ThunderSky 60Ah
| 0.5 A
| ✓
| -
| ✓
| -
| CAN
| -
| -
| -
| Plastic
|
| IQ
| Master Slave
| 256
| Any
| 0.25 A
| ✓
| ✓
| ✓
| -
| CAN
| ✓
| ✓
| -
| -
|
REAP systems
Dennis Doerffel
UK
England
| 
| -
| Non-distributed,
Modular
| 4~168
| Any
| ✓
| ✓
| ✓: 2 inputs
| ✓
| -
| Wire
CAN
RS232
RS485/
RS422
| -
| ✓: 2
| Avail.
| -
|
Ventec
France
| 
| iBMS
for hybrids
| Non-distributed,
Master/slave
| 4~350
| Any
| ✓
| ✓
|
| ✓
| -
| CAN
| -
| -
| -
| Metal
|
Company
(1)
| Picture
(2)
| Model
| Topology
(3)
| No of cells
(4)
| Cell shape
(5)
| Balance
current
| Temper.
(7)
| Curr.
sense
(8)
| "Fuel
gauge"
(9)
| Isol. detect
| Comm.
(10)
| Fan
drive
(11)
| Contac.
drive
(12)
| Displ.
(13)
| Case
(14)
|
Sophisticated digital technology, able to measure and report every cell voltage, to calculate SOC, and to request that the battery current be shut off to protect it.
Not able to balance the battery pack.
To see additional information, hover your cursor over the icons.
Company
(1)
| Picture
(2)
| Model
| Topology
(3)
| No of cells
(4)
| Cell shape
(5)
| Temper.
(7)
| Curr.
sense
(8)
| "Fuel
gauge"
(9)
| Comm.
(10)
| Fan
drive
(11)
| Contac.
drive
(12)
| Displ.
(13)
| Case
(14)
|
Electric Blue Motors
Bill Schlanger
US
Arizona
| 
| Blue View
| Distributed
| 1~255
| Any
| ✓
| ✓
| ✓
| Wire
| -
| -
| ✓
| Metal
|
Guantuo
China
Heilongjiang
| 
| GTBMS005A-MC8
| Non-distributed,
Master/slave
| 100
| Any
| ✓
| ✓
| ✓
| Wire
| -
| -
| ✓
| ✓
|
| GTBMS005A-MC11
| Wire, CAN, USB
| ✓
|
| GTBMS005A-MC16
|
| GTBMS005A-MC17
| ✓
|
Company
(1)
| Picture
(2)
| Model
| Topology
(3)
| No of cells
(4)
| Cell shape
(5)
| Temper.
(7)
| Curr.
sense
(8)
| "Fuel
gauge"
(9)
| Comm.
(10)
| Fan
drive
(11)
| Contac.
drive
(12)
| Displ.
(13)
| Case
(14)
|
LEM
Switzerland
| 
| Sentinel / S-Box
| Non-distributed,
Master/slave
| 255
| Any
| ✓
| ✓
| -
| Ethernet
| -
| -
| -
| Metal
|
Lithium Start
Thomas Cook
US - CA
San Francisco
|
| BluFlex
| Distributed
| Any
| 26650 small cyl.
| ✓
| -
| -
| Wire
| -
| -
| -
| -
|
Rozwiazania dla EV
("Solutions for EV")
Poland
| 
| iBMS
| Non-distributed,
Master/slave
| 4~24
| Any
| ✓
| ✓
| ✓
| Wire
RS485
| -
| -
| ✓
| -
|
Shenzhen Junsi Electronic Co
Shenzhen, China
| 
| S8
| Non-distributed,
Centralized
| 2~8
| Any
| -
| -
| -
| USB
Wire
| -
| -
| ✓
| Plastic
|
Worley Parsons
Rebranded by Leo industries,
Singapore
UK
| 
| LBSU-4-100
| Non-distributed,
Centralized
| 4~28
| Any LiPo
| ✓
| -
| -
| Wire /
simplex
RS232
| -
| ✓
| -
| -
|
Company
(1)
| Picture
(2)
| Model
| Topology
(3)
| No of cells
(4)
| Cell shape
(5)
| Temper.
(7)
| Curr.
sense
(8)
| "Fuel
gauge"
(9)
| Comm.
(10)
| Fan
drive
(11)
| Contac.
drive
(12)
| Displ.
(13)
| Case
(14)
|
Sophisticated digital technology, able to measure and report every cell voltage.
Not able to balance the battery pack; does not protect the battery (does not request that the battery current be shut off).
To see additional information, hover your cursor over the icons.
Company
(1)
| Picture
(2)
| Model
| Topology
(3)
| No of cells
(4)
| Cell shape
(5)
| Temper.
(7)
| Curr.
sense
(8)
| "Fuel
gauge"
(9)
| Comm.
(10)
| Fan
drive
(11)
| Contac.
drive
(12)
| Displ.
(13)
| Case
(14)
|
CasaDelGato
John Lussmyer
US
Washington
| 
| -
| Non-distributed,
Master/slave
| 10
| Any
| ✓
| -
| -
| -
| -
| -
| ✓
| Plastic
|
Shenzhen Junsi Electronic Co
China
| 
| CellLog8s
| Centralized
| 8
| Any
| -
| -
| -
| -
| -
| -
| Incl.
| Plastic
|
KJHall Motor Co
Ken Hall
US
Colorado
| 
| PakTrakr
| Non-distributed,
Master/slave
| 6~30
| Any
| ✓
| ✓
| -
| RS232
| -
| -
| Incl.
| Plastic
|
- A protection circuit is a BMS that also includes a way to interrupt the battery current to protect the battery (unlike a protection circuit, a standard BMS must rely on external devices (charger, motor controller, contactors) to reduce or stop the battery current when the BMS tells them to)
- Protection circuits usually are meant for small batteries (cell phones, laptops) as they can usually only handle a few Amps of battery current
Sources of commercially available circuit protectors for small Li-Ion batteries:
- Baleaf Energy, China: PCMs for 3 to 24 cells in series, 8 to 300 A
- All battery.
- SmarTec.
- Smart Electronics.
- Pow-R Solve, from Southwest Electronic Energy Group
- BMS Version 2.6, from Rechargeable Lithium Power; simple analog; cell level LVC and HVC with charger current control, balance; up to 24 cells; based on the Fechter/Goodrum open source design
- BMS Version 4.0, from Rechargeable Lithium Power; simple analog; cell level LVC and HVC with charger current control, balance, fan control, 50 A battery current switch; scalable to 400V packs; based on the Fechter/Goodrum open source design
- Overview, All-In-One, 4, 5, 8, 12 and 16 in series, BV48A60, 16 series,from Yesa
- Various, from ONS power
- Various from ECityPower, sold by BMS battery and EVPST
- BMS4S1P-STD, from Cyclone
- 24 V, 36 V and 48 V, from Kennedy Alternative Energy
- BMS4S1P-STD, from Cyclone
- Signalab
- Powerlogics
- Micro Vehicle Lab
- Methtek. Hobby King Lipo Protection Kit No balancing. allows paralleling up to 8 each of 6S battery modules, and then series any number of them.
- Shenzhen Klclear Technology, BMB01, 16-cell protector, 10 A or 50 A, for UPSs
- Best Tech Power, PCMs, balancers, and other components for small batteries, ShenZhen,China.
- Shenzhen Unwisemen Technology : PCMs, balancers, and other components for small batteries, ShenZhen,China.
Simple analog technology, just able to detect that some cell's voltage is too low or too high, but unable to report which one. Able to balance the battery.
To see additional information, hover your cursor over the icons.
Simple analog technology, just able to detect that some cell's voltage is too low or too high, but unable to report which one nor to balance the battery.
To see additional information, hover your cursor over the icons.
Regulators (also called "equalizers" or "balancers") are sometimes used in Li-Ion packs as a simple protection against overcharging.
A regulator is required across each cell.
A regulator performs balancing during charging by bypassing charging current from the fully charged cells, so that other cells in the battery can finish charging.
Elite Power Solutions Battery Balancer.
What regulators do:
- Regulator remove excess energy from cells whose voltage is above a certain threshold, but that's all they do
What regulators don't do:
- Regulator can't keep individual cells in a battery from overcharging
- Regulator don't monitor the entire battery, and don't report on its status
- Regulators do not protect a pack from undercharging
- Regulators are not able to tell the charger to stop charging: a human has to keep an eye on the regulators (which usually have LEDs) and shut down the charger
- Regulators cannot not tell external devices to slow down or stop charging or discharging; therefore, a pack with regulators can still be under-charged, and overcharging may damage the regulators
- Regulators can't protect themselves from overheat: they will be damaged if a CCCV charger's end current is higher than the regulators can bypass
EXCEPTION: The EV West bottom balancer actually does things the other way around:
- Instead of top balancing, it bottom balances: it removes energy from a cell until it's empty
- Instead of being permanently mounted on a cell, it is used only once, at manufacture, to empty a single cell at a time
- Instead of being installed in addition to a non-balancing BMS, this bottom balancer is intended to be used without any BMS at all
Sources of commercially available regulators for Li-Ion cells:
- Linano - Prismatic cell - Europe
- CBM1 - Cell Balancing Module - 3.60V- 1.7A - Europe
- Hot Juice Electric - US - Texas. No longer made.
- Volt Blocher by Brian Blocher - regulator for a single LiFePO4 cell. No longer made.
- Elite Power Solutions Battery Balancer sold by Electric Blue Motors - regulator for a single LiFePO4 prismatic cell
- For 90 Ah prismatic cells
- Probably on the order of 200 mA balance current
- Fixed 3.7 V voltage
- Not ideal for LiFePO4 cells: the shunt voltage is a bit too high
- Won't work with Thundersky cells: the shunt voltage is too low
- Won't allow LiPo and cobalt lithium cells charge fully: the shunt voltage is too low
- $ 13 each
- Bat Guard, by LL Labs (no website), sold by Anida in Dallas, TX, US
- High power regulator: 4 A max current
- While shunting, a yellow LED is lit.
- If the fuse blows, a red LED will light, but cell will soon be toast, so a human has to watch the LEDs at all times
- Fixed 3.67 V knee voltage, 3.7 V max voltage
- Not ideal for LiFePO4 cells: the shunt voltage is a bit too high
- Won't work with Thundersky cells: the shunt voltage is too low
- Won't allow LiPo and cobalt lithium cells charge fully: the shunt voltage is too low
- Between $ 40 to $ 60 each, depending on quantity
- Company: Trade names are the property of their respective owners. A few other companies are getting ready to offer Li-Ion BMSs, but are not yet ready to be listed here (for example, Evie Systems).
- Picture:
• Click to see the complete picture (if available)
- Topology (more info):
• BMS: does not include a switch to cut off the battery current
• Protector: includes a switch to cut off the battery current
• Centralized ("spaghetti"): single BMS controller with n+1 wires going to n cells
• Centralized with slaves: single BMS controller connected to a few slave boards, each with n+1 wires going to n cells
• Modular: single BMS controller with n+1 wires going to n cells; expanded by adding more, identical BMS controllers
• Distributed: small board mounted on each cell; BMS controller connected just to the 2 cells at either end of a battery
- Number of cells: this is the acceptable range in the number of cells in series. The number of cells in parallel does not matter.
- Cell shape:
• Small cylindrical: cylindrical cells to be welded, such as the 18650 or the 26650 sizes
• Large cylindrical: cylindrical cells with screw terminations at either end
• Prismatic: boxy cells with screw terminations on top, such as Thundersky
• Pouch: soft bags with tabs on one end, such as Kokam
• Any: there are no electronics on the cells, so the BMS works with all the above, using wires
- Balance: The BMS is able to remove energy just from the most charged cells, to allow the other cells to reach the same level of charge. A balanced pack will have the maximum possible capacity. This is not as important for Hybrid Electric Vehicles.
- Temperature: The BMS is able to measure and report individual cells' temperature. (The 'more info' tells you if the temperature measurement is not for every cell.)
- Current sense: The BMS includes a current sensor or at least an input for a current sensor, to measure battery current. This enables the BMS to react to excessive current, and to calculate the SOS or DOD.
- "Fuel gauge": a.k.a.: "Gas Gauge". The BMS calculates the SOC (State Of Charge) or DOD (Depth Of Discharge), by integrating the battery current. Devices that simply use the voltage to estimate SOC are not included here.
- Communications: In general, the BMS must communicate with the rest of the system, to report the status of the pack, and be able to limit charging and discharging of the pack, in order to protect it.
• Wire: separate wires are used, each with a single, specific function, such as to turn on the charger relay.
• CAN: CAN bus, common in vehicles and European industrial equipment.
• RS232: serial point-to-point communication, usually used only for initial set-up and testing, but some time also available for communication during operation.
- Fan: The BMS is able to control or drive a cooling system
- Contactors: The BMS is able to control or drive a set of contactors between the battery pack and the load, including a precharge relay. Many motor controllers already have this function built in, so BMS controller that includes this function is not required.
- Display: Either the BMS includes a SOC display, or the company sells a display that is compatible with the BMS.
- Case: Whether the BMS controller is enclosed (metal or plastic case), or it is an open PCB assembly. Unless otherwise noted, any cell-mounted boards are assumed to be open PCB assemblies.
- Price: from manufacturers' websites or discussion with them or their clients. Conversions into US $ based on rates effective at the time of writing. Unless otherwise noted, prices are for small quantities.
Companies that offer custom BMS designs:
- Panacis - Ottawa, Ontario , Canada
- Nuvation - US / Canada - Reference design, available as a jump off point to your own BMS: digital / master slave / 12 cells per slave (1 thermistor per cell), 744 cells max
- Harbin Coslight Power - China
- Lithium Power Solutions - US - Indiana
- Black Sheep Technology - US, Colorado
- Energy CS - US - California
- Metric Mind, US - Oregon, with their SmoothTalk BMS line
- MPower (Axeon Power) - UK - Scotland
- REAP - UK
- BMS, from ITI Energy, for which they invested 1.5 million pounds!
- Generic BMS, from Ricardo: central with slaves (up to 16 cells / slave), very high measuremeny accuracy.
- Zanthic, Steve Letkeman - Canada
- Launch Point - High reliability BMS
Some open source, DIY BMS projects:
List of available BMSs (not just Li-Ion)
BMSs from cell manufacturers, only sold together with their cells.
Therefore, these BMS are not considered to be commercially available.
They are presented here only for reference
To see additional information, hover your cursor over the icons.
Cell company
(1)
| BMS company
(1)
| Picture
| Model
| Topology
(3)
| Function
| No of cells
(4)
| Temper.
(7)
| Curr.
sense
(8)
| "Fuel
gauge"
(9)
| Comm.
(10)
| Fan
drive
(11)
| Contac.
drive
(12)
| Displ.
(13)
| Case
(14)
| Price
|
| Elite Power
| EPS
| 
| -
| Distributed
| Digital balancer
| 200
| ✓
| ✓
| ✓
| Wire
| -
| -
| ✓
| Plastic
| $370 / 16 cells
$470 / 24 cells
$1425 / 100 cells
|
| Kokam
| N-Tech
| -
| -
| Non-distributed,
Modular
| Digital balancer
| 4~14 each
/ 112 max
| ✓
| ✓
| ✓
| CAN
Serial
| -
| -
| -
| ?
|
|
| Thundersky
| Ningbo Yangming
(no link: attack website)
| BMS40
| Non-distributed,
Master/slave
| Digital monitor
| 10,20,
30...100
| ✓
| ✓
| ✓
| ?
| ?
|
| Incl.
| Metal
|
|
| Valence
| Valence
| 
| U-BMS
| Modular
| Digital balancer
| 4~768 each
| ✓
| ✓
| ✓
| CAN
| -
| ✓
| -
| Plastic
|
|
Cell company
(1)
| BMS company
(1)
| Picture
| Model
| Topology
(3)
| Function
| No of cells
(4)
| Temper.
(7)
| Curr.
sense
(8)
| "Fuel
gauge"
(9)
| Comm.
(10)
| Fan
drive
(11)
| Contac.
drive
(12)
| Displ.
(13)
| Case
(14)
| Price
| |
Also.
The following are not BMSs, but perform related functions.
- Cycle Analyst, battery meter for electric bikes
- EV Display, SOC calculator, etc.
- CellLog, from Shenzhen Junsi Electronic Co: a logger of up to 8 Li-Ion cells (no SOC). It has an alarm output which could be used as a "poor man's" BMS
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Li-Ion BMS
Parametric BMS selector
