Li-Ion BMS

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.

back to topParametric BMS selector

Go to the Parametric BMS selector utility.

back to topBMS types

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

back to topPrices
Digital BMSs anchor
Price vs number of cells
Digital Protectors and Balancers
Note: log scales. Sources: (15)
Analog BMSs anchor
Price vs number of cells
Protectors (thin line), Balancers (thick line).
Note: log scales. Sources: (15)
back to topDigital protectors

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 more info 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
Click to see the BMS VMS / GBTS Non-distributed,
Modular
1~24
more info
Any - - Wire
serial
more info
- -
more info
-
more info
Chargery
China
GuangDong
Click to see the BMS B series Non-distributed,
Centralized
1~12
more info
Any - - - - -
more info
Metal
Clayton power
UK
Click to see the BMS 'C' and 'CF'series
more info
Non-distributed,
Centralized
4, 8, 12, 15, 19 or 23
more info
Any
more info
125 to 300 A cont.;
800 to 100 A peak

more info

incl.
CAN
RS232
Wire
more info
- Incl. Metal
e-chip
China
Hong Kong
Click to see the BMS BMS-xxS-xxxA Non-distributed,
Centralized
more info
4,8,13,16,26 Any 100 A
more info
- CAN
more info
- Optional Metal
Lithium Balance
Birger Carlsen
Denmark
Click to see the BMS iBMS
more info
Non-distributed,
Centralized
more info
15, 19 or 23
more info
Any
more info
140 A to 250 A cont.
600 A peak

more info

incl.
Wire /
simplex
RS232
more info
- - Metal
Lithium Start
Thomas Cook
US - CA
San Francisco
Click to see the BMS BluFlex Distributed
more info
4 Any - - -
more info
- - -
Ventec
France
Click to see the BMS 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)

back to topDigital balancers

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.

Price vs number of cells

Note: log scales. Sources: (15)

To see additional information, hover your cursor over the more info 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
Click to see the BMS 123 BMS Distributed
more info
1~255 Prismatic 1 A - USB - - - -
more info
BatteryMan
Germany
Click to see the BMS iBM Distributed
more info
Any Any 0.01 A - -
more info
- - - -
Black Sheep Technology
Ron Anderson
US
No. Carolina
Click to see the BMS Stack V1 Non-distributed,
Modular
1~32
more info
Any - Serial -
more info
Cage V2 Non-distributed,
Centralized
1~48
more info
- Serial
Mini V3 Non-distributed,
Master/slave
Any
more info
- Serial
BMS Auto V4 Non-distributed,
Master/slave
Any
more info
- Serial Automotive
grade
Clayton power
UK
Click to see the BMS - Non-distributed,
Master/slave
up to 496
more info
Any 1.5 A - ? - - - Plastic
Convert the future
Mark Hardy
US
CA
Click to see the BMS Flex BMS48 Non-distributed,
Centralized
48 Any - Internal Bus - Plastic
Click to see the BMS Flex BMS84 Non-distributed,
Centralized
84 Any - Internal Bus - Plastic
Elektromotus
Gintautas Paluckas
Lithuania
Click to see the BMS EMUS BMS Distributed 4~256
more info
Prismatic 1.3 A
more info

more info
- Wire
CAN
USB
RS232

more info
- 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
Click to see the BMS Lithiumate™ Pro Distributed 2~255 Sml cyl
Lrg cyl
Prism.
Pouch
0.2 A /
3 A
more info
1 / cell
more info
Wire
CAN
RS232
Avail.
GUI
Metal
more info
Click to see the BMS Lithiumate™ Lite Distributed 2~200 Prismatic 0.2 A /
3 A
more info
1 / cell
more info
- Wire
USB
- - Avail.
more info
GUI
Plastic
Click to see the BMS Lithiumotive™
Not yet released
Distributed or non-distributed 1~65535 Any 0.1 A /
3 A
more info
1 / cell 1000 A
more info
Wire
CAN
USB
GUI Sealed composite
Elecyr

Bill Southworth
US
New Hampshire
Click to see the BMS CellCard /
ConnectCard
more info
Distributed
Master /slave
more info
1~350
more info
Any
more info
3 A
more info
1 / cell
more info
600 A CAN, WiFi or Ethernet
more info
-
more info
more info
more info
Plastic
Evaira
US
California
Click to see the BMS CellSpy Non-distributed,
Master/slave
224
more info
Any - CAN
RS232
Ethernet
- - - Metal, sealed
Click to see the BMS International Rectifiers' EMS Non-distributed,
Master/slave
200 max
more info
Any 0.2 A - CAN
RS232
Ethernet
- - - -
EVLithium
(Norway)

Ronny Titternes
(Not to be confused by the Chinese reseller by the same name.)
Click to see the BMS EV Mini BMS Distributed 1~400
more info
Prismatic 0.25 to 1 A - - - - RS232
Wire
- - - -
EVPST
China
Guangzhou
Click to see the BMS BMS-4 Non-distributed,
Master/slave
??? Any - CAN
RS485
- - Metal
Ewert Energy Systems
Chris Ewer
US
Illinois
Click to see the BMS Orion™ Non-distributed,
Centralized
1~180 Any
more info
Wire
CAN
- GUI Metal
Flux Power
Escondido CA
USA
Click to see the BMS no name Non-distributed,
Master/slave
1024
more info
Any 1 A - - - CAN - -
more info
Sealed metal
Gannon

USA
Click to see the BMS no name Non-distributed,
Master/slave
200
more info
Any 200 mA / 3 Amore info 1/ 6 cells - CAN - - GUI Open
GfE/GK-Anlagentechnik
Germany
EU
Click to see the BMS none Distributed 16 100 Ah prismatic - - -
more info
-
GWL Power
Guernsey
Channel islands
EU
Click to see the BMS RT-BMS Non-distributed,
Master/slave
192
more info
Any - CAN
RS232
USB
-
more info
Plastic
Jon Elis
Lithuania
EU
Click to see the BMS BMS ver.2 Distributed 254 Prismatic ✓ 2 A - CAN
USB
Bluetooth
- -
more info
-
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
Click to see the BMS IME Non-distributed,
Master/slave
140 max
more info
Any - CAN
RS232
- - - -
Shanghai Founding New Energy Technology
/ Leoyun New Energy
China

Resold by EVlithium (China)
Click to see the BMS 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)
Click to see the BMS AUTO_EMS_2.0
EHUG BMS
LIGOO BMS
EK30
Non-distributed,
Master/slave
5~104
more info
Any
more info
CAN
RS485
USB

more info
Metal
Click to see the BMS EK-FT-11 12 max Any CAN
RS485
Metal
EK-FT-12 16 max
EK-FT-21 25 max
EK-YT-21 24 max
Click to see the BMS YD-UP-21
more info
12~16 Metal
MT-JS-11
more info
?
MT-JS-21
more info
?
ES-DY-13
more info
?
Lithium Balance
Birger Carlsen
Denmark
Click to see the BMS sBMS
more info
Non-distributed,
Master/slave
more info
256 Any - CAN
wire
- - - Sealed metal
more info
Manzanita Micro
Rich Rudman
US
Washington
Click to see the BMS MK3x4SMT
more info
Non-distributed,
Master/slave
Any Any - - - Wire
more info
- - - -
Methods
Patrick Schindler
US
California
Click to see the BMS LTC BMS
more info
Non-distributed,
Centralized
36
more info
Any - Wire
USB
- - - Aluminum
Millen Works
Rod Millen
US
California
Click to see the BMS - Non-distributed,
Master/slave
more info
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)
O'Cell Technology
China, Shenzhen
Click to see the BMS BMU LV-150 Master/Slave
more info
4~218 Any CAN - Included Plastic, IP56
Pacific EV
Cory Cross
US
Washington
Click to see the BMS TBMS Distributed
more info
1~? Prismatic
more info
- - - Wire
more info
- - - -
Peter Perkins
UK
Click to see the BMS V series
more info
Distributed or
Non-distributed,
Master/slave
more info
1~255
more info
Prismatic - Wire
RS232
- - Included -
more info
REC
Slovenia
EU
Click to see the BMS BMS 7 Master/Slave
more info
210 Any 1.3 A ✓:
380 A
- CAN, RS485 GUI Metal
more info
Tritium
David Finn
Queensland
Australia
Click to see the BMS IQcell Distributed
more info
256
more info
ThunderSky 60Ah 0.5 A -
more info
- CAN - - - Plastic
Click to see the BMS IQ Master Slave
more info
256
more info
Any 0.25 A
more info

more info
- CAN - -
REAP systems
Dennis Doerffel
UK
England
Click to see the BMS - Non-distributed,
Modular
more info
4~168
more info
Any ✓: 2 inputs - Wire
CAN
RS232
RS485/
RS422
more info
- ✓: 2
more info
Avail. -
more info
Ventec
France
Click to see the BMS iBMS
for hybrids
Non-distributed,
Master/slave
4~350
more info
Any - CAN - - - Metal
more info
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)

back to topDigital monitors

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 more info 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
Click to see the BMS Blue View Distributed 1~255
more info
Any Wire - -
more info
Metal
Guantuo
China
Heilongjiang
Click to see the BMS GTBMS005A-MC8 Non-distributed,
Master/slave
100
more info
Any Wire - -
more info
Click to see the BMS GTBMS005A-MC11 Wire, CAN, USB
more info
Click to see the BMS GTBMS005A-MC16
Click to see the BMS 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
Click to see the BMS Sentinel / S-Box Non-distributed,
Master/slave
more info
255 Any - Ethernet - - -
more info
Metal
more info
Lithium Start
Thomas Cook
US - CA
San Francisco
Click to see the BMS BluFlex Distributed
more info
Any 26650 small cyl. - - Wire
more info
- - - -
Rozwiazania dla EV
("Solutions for EV")
Poland
Click to see the BMS iBMS
more info
Non-distributed,
Master/slave
more info
4~24
more info
Any
more info

more info
Wire
more info
RS485
- -
more info
-
Shenzhen Junsi Electronic Co
Shenzhen, China
Click to see the BMS S8 Non-distributed,
Centralized
2~8 Any - - - USB
Wire
- - Plastic
Worley Parsons
Rebranded by Leo industries,
Singapore
UK
Click to see the BMS LBSU-4-100 Non-distributed,
Centralized
more info
4~28
more info
Any LiPo
more info
- - Wire /
simplex
RS232
more info
-
more info
- -
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)

back to topDigital meters

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 more info 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
Click to see the BMS - Non-distributed,
Master/slave
10
more info
Any
more info
- - - - -
more info
Plastic
Shenzhen Junsi Electronic Co
China
Click to see the BMS CellLog8s Centralized 8
more info
Any - - - - - - Incl. Plastic
KJHall Motor Co
Ken Hall
US
Colorado
Click to see the BMS PakTrakr Non-distributed,
Master/slave
more info
6~30 Any
more info

more info
- RS232 - - Incl. Plastic

back to topAnalog protectors (PCM)

  • 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:

back to topAnalog balancers

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 more info icons.
Company
(1)
Picture
(2)
Topology
(3)
No of cells
(4)
Cell shape
(5)
Balan.
(6)
Temper.
(7)
Curr.
sense
(8)
"Fuel
gauge"
(9)
Comm.
(10)
Displ.
(13)
Case
(14)
Price,
14-cell
[US$]
(15)
Adequate Energy
South Africa
Click to see the BMS Non-distributed,
Centralized
more info
24 Any
more info
- - - - - - -
Agni motors
Stybrook Ltd
Cedric Lynch
India / Britain
Click to see the BMS Distributed 1~200 Prismatic - - - Wire - - 261
Black Sheep Technology
Ron Anderson
US
Colorado
Click to see the BMS Distributed 1~any Prismatic
more info
-
more info
-
more info
-
more info
-
more info
-
more info
- 560
Belktronix
Bryan Belk
US
California
Click to see the BMS Distributed 1~44 Any
more info
- - - Wire - - ?
Clean Power
MiniBMS
US
Florida
Click to see the BMS Distributed or non-distributed
more info
Any Prismatic
more info

more info
- - - Wire - - 198
Company
(1)
Picture
(2)
Topology
(3)
No of cells
(4)
Cell shape
(5)
Balan.
(6)
Temper.
(7)
Curr.
sense
(8)
"Fuel
gauge"
(9)
Comm.
(10)
Displ.
(13)
Case
(14)
Price,
14-cell
[US$]
(15)
EV Power
Rod Dilkes
Australia
W. Aus.
Compatible with Zeva's EVMS
Click to see the BMS Distributed 1~any Prismatic - - - Wire -
more info
Metal
more info
186
EV Works
Rod Dilkes
Australia
W. Aus.
Click to see the BMS Centralized 8 Any - - - Wire - -
LiPoTech
Francesco Tosoni
San Marino
(Italy)
Click to see the BMS Distributed
more info
1~any Any
more info
- - - Wire
more info
-
more info
- € 40 /
4-cells
Low Carbon Idea
China
Click to see the BMS Distributed
more info
1~any For 40 Ah prismatic LiFePO4 cells - - Wire - - -
High Tech Systems
Derek Barger
No info on web
US
Colorado
- Distributed
more info
1~any
more info
Sml cyl.
Lrg cyl.
more info

more info
- - Wire
more info
Incl.
more info
-
more info
480
Company
(1)
Picture
(2)
Topology
(3)
No of cells
(4)
Cell shape
(5)
Balan.
(6)
Temper.
(7)
Curr.
sense
(8)
"Fuel
gauge"
(9)
Comm.
(10)
Displ.
(13)
Case
(14)
Price,
14-cell
[US$]
(15)

back to topAnalog monitors

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 more info icons.
Company
(1)
Model Picture
(2)
Topology
(3)
No of cells
(4)
Cell shape
(5)
Temper.
(7)
Curr.
sense
(8)
"Fuel
gauge"
(9)
Comm.
(10)
Displ.
(13)
Case
(14)
Price
[US$]
(15)
Thunderstruck
US, CA
BMS-X Click to see the BMS Distributed Any Prismatic
M8 bolt only
- - - Wire
more info
- - $ 150 + $ 15 / cell

back to topRegulators / equalizers / balancers

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.

balance on cell
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
back to topNotes
  1. 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).
  2. Picture:
    • Click to see the complete picture (if available)
  3. 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
  4. Number of cells: this is the acceptable range in the number of cells in series. The number of cells in parallel does not matter.
  5. 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
  6. 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.
  7. 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.)
  8. 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.
  9. "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.
  10. 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.
  11. Fan: The BMS is able to control or drive a cooling system
  12. 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.
  13. Display: Either the BMS includes a SOC display, or the company sells a display that is compatible with the BMS.
  14. 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.
  15. 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.
back to topCustom BMSs

Companies that offer custom BMS designs:

back to topDIY BMSs

Some open source, DIY BMS projects:

List of available BMSs (not just Li-Ion)
back to topCell manufacturer BMSs

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 more info 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 Click to see the BMS - Distributed Digital balancer 200 Wire - - Plastic $370 / 16 cells
$470 / 24 cells
$1425 / 100 cells
more info
Kokam N-Tech - - Non-distributed,
Modular
Digital balancer 4~14 each
/ 112 max
more info

more info
CAN
Serial
- - -
more info
?
Thundersky Ningbo Yangming
(no link: attack website)
Click to see the BMS BMS40 Non-distributed,
Master/slave
Digital monitor 10,20,
30...100

more info
? ? Incl.
more info
Metal
Valence Valence Click to see the BMS U-BMS Modular Digital balancer 4~768 each
more info
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.

back to topUpcoming
back to topOther

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

© 2008~2014 Davide Andrea. All rights reserved, except where noted by CC mark. Page published on Jan 10 2014. Graphic design by morninglori
 

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