1 / 2JKBMS JK-B1A / B2A Series
B1A/B2A smart active-balance BMS for DIY and system battery packs
JKBMS JK-QB2A8S20P Parking Start Dedicated BMS is a JK B1A/B2A active-balance BMS listed from $180.00. It is intended for lithium battery packs where the exact series count, current rating, balance current, and communication features need to be confirmed before ordering.
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Product details
SELECTION HELP
Check strings, current, active balancing, display, and communication requirements before comparing models.
Read guideBALANCING GUIDEUnderstand how balance-current class relates to cell capacity, imbalance, and correction time.
Read guideCOMMUNICATION GUIDESeparate physical interface choice from inverter protocol and system compatibility requirements.
Read guideFIT AND INSTALLATION NOTES
JK-QB2A8S20P pairs 2A balancing with high current in a small package, which concentrates heat. On a 12V or 24V build the enclosure usually runs out of thermal headroom before the board runs out of rating, so plan ventilation and terminal sizing alongside the electrical spec.
Bought for a compact pack where balance rate matters more than headline current. Within the JK-B2A series, that is the job this one is sized for.
The numbers to design against: 4-8S series, 200A continuous, 2A balancing. Read them against the load and the cells, not against another model's headline figure.
Communication on this unit is Bluetooth, Charger check, Display, Forced start switch, GPS Support, Heating Function. That establishes what it can speak, not whether a given inverter will answer; the protocol profile, pinout and both firmware versions still decide that.
Family position
QB2A8S20P| Model | Strings | Continuous | Balance | From, US$ |
|---|---|---|---|---|
JK-B1A8S10P | 8S | 100A | 1A | 71.16 |
JK-B1A8S20P | 8S | 200A | 1A | 79.98 |
JK-B2A8S20P | 8S | 200A | 2A | 89.98 |
| JK-QB2A8S20Pthis listing | 8S | 200A | 2A | 180.00 |
JK-B2A8S30P | 8S | 300A | 2A | 109.98 |
JK-B1A20S15P | 20S | 150A | 1A | 86.38 |
JK-B2A20S20P | 20S | 200A | 2A | 146.98 |
JK-B1A24S15P | 24S | 150A | 1A | 86.98 |
JK-B2A24S15P | 24S | 150A | 2A | 106.98 |
JK-B2A24S20P | 24S | 200A | 2A | 159.98 |
JK-B2A24S30P | 24S | 300A | 2A | 174.98 |
JK-B2A25S-CR60P | 25S | 600A max | 2A | 377.00 |
The closest step below this board inside QB2A is JK-B1A8S10P: same 8S ceiling, same 2A balancer, only the continuous rating moves, to 100A. US$108.84 separates the two at the base configuration. Size that gap against the load actually drawn, because nothing else about the two boards changes.
Same current, different ceiling: JK-B2A20S20P runs to 20S where this board stops at 8S, which is 12 more cells in series. Choose on the cell stack, because no setting converts one into the other.
JK-B1A8S20P is the other candidate for the same pack: 8S, 200A, 1A balancing rather than 2A. It sits US$100.02 below this listing at the base configuration. If the cells are matched and the duty cycle leaves idle time, the cheaper of the two is the right answer; if they are not, no protection setting replaces balance current.
On price inside QB2A this listing sits at 12 of 14: US$180.00 for the base configuration, against a family spread of US$71.16 (JK-B1A8S10P) to US$377.00 (JK-B2A25S-CR60P). Configuration add-ons shift that position, so compare like-for-like variants rather than headline figures.
Model planning
The figures below are the ones that decide whether JKBMS JK-QB2A8S20P Parking Start Dedicated BMS works in a given pack. Read them against the cells and the load before ordering.
System fit checks
Four things worth settling while the order is still changeable, and one worth doing in the right order once the hardware arrives.
Confirm the battery pack is within 4-8S. Match the 200A continuous discharge rating to the inverter, load, wiring, and thermal design. Use the 2A active-balancing class as one selection input, not as a substitute for good cell matching.
The listed communication options are Bluetooth, Charger check, Display, Forced start switch, GPS Support, Heating Function. Confirm protocol, pinout, baud rate or CAN bitrate, firmware, and inverter compatibility before installation.
Use suitable fusing, cable size, torque, ventilation, insulation, and commissioning checks for the final battery system.
Bring the pack up on local monitoring and confirm the cell readings look sane before connecting anything downstream. Debugging a protocol handshake against a pack that has an unrelated wiring or balance fault costs most of a commissioning day.
Buying notes
Practical points buyers raise before paying: where the product comes from, what documentation to check first, how it ships, and how the price is set.
This catalogue is operated by JKBMS Electronic Technology Co.,Ltd rather than a reseller, so model configuration, documentation, and warranty questions are answered by the manufacturer instead of being referred upstream.
Parameter sets and connector assignments differ between model families and hardware revisions. Download the manual for this exact model and check it against your pack before commissioning rather than relying on a similar model.
JKBMS boards, monitors, displays, and accessories ship free worldwide. Delivery time depends on destination and customs handling rather than on the order value.
Each configuration is priced separately and the total is re-checked on the server at checkout, so the price shown for the selected SKU is the price charged. Larger quantities are quoted separately through a bulk enquiry.
Product FAQ
JKBMS JK-QB2A8S20P Parking Start Dedicated BMS is a JK B1A/B2A active-balance BMS listed from $180.00. It is intended for lithium battery packs where the exact series count, current rating, balance current, and communication features need to be confirmed before ordering.
Check continuous current (200A), balance rate (2A), the port set (Bluetooth, Charger check, Display, Forced start switch, GPS Support, Heating Function) against the pack you are building. The order that matters: series count has to match the cells, current has to cover the load with margin, and the port set has to leave a free port for whatever the system talks to.
Selected JKBMS smart BMS model or display bundle; Model-specific wiring harness and standard accessories supplied with the product; Documentation or setup references supplied with the selected package. Not included: Battery cells, battery enclosure, inverter, charger, and external power cabling; External contactors, breakers, fuses, and installation hardware unless specified. Where a configuration option changes the contents, the option selected at checkout is what ships.
JK-QB2A8S20P is stocked here as a jkbms jk-b1a / b2a series listing. JKBMS hardware is built by JKBMS Electronic Technology Co.,Ltd, and BatteryBoxKit is the storefront that holds and ships it, so orders leave from held stock and confirmations come from zhou@jkess.com.
This listing carries a single configuration. Order directly from this page; boards, displays, cables and accessories ship free. If the cart also includes a battery kit, that kit's destination-based shipping rule applies, so confirm the destination before paying.
Shipping and return terms apply to this listing and to every configuration shown above.
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