A JST-XH balance lead keeps every cell in a LiPo pack at the same voltage. A 2S pack uses a 3-pin balance plug, while a 6S pack uses a 7-pin plug. Balance adapters link odd plugs to a standard charger. Extension leads reach a charger on the bench. This guide compares the JST and balance connectors by cell count.
What does a balance lead do?
A balance lead gives the charger one wire per cell plus a ground. The charger reads each cell at 4.20 V when full.
Without a balance lead, cells drift apart over cycles. A pack with one cell at 4.30 V and one at 4.10 V is unsafe to use.
How many pins does a balance plug need?
A 2S pack uses a 3-pin JST-XH plug, and a 6S pack uses a 7-pin plug. The pin count is always the cell count plus one.
A 4S pack uses a 5-pin plug on 22 AWG wire. Count the pins before you order extensions or adapters.
What is a JST-XH connector saver?
A connector saver is a short adapter that takes the wear of plugging and unplugging. It protects the balance plug on the pack itself.
A 2S saver and a 4S saver come in 5-packs. Use a fresh saver when the old one feels loose.
Which balance adapter fits your charger?
A JST to JST-XH adapter set covers 2S through 6S packs. It links odd-plug packs to a standard balance charger.
The set uses 20 AWG wire and JST-XH plugs on the charger side. Check the pin order twice before the first charge.
How do balance extension leads work?
A JST-XH extension adds 20 cm of 22 AWG wire between the pack and the charger. It comes in 1S through 6S versions in 5-packs.
Use an extension when the pack sits far from the charger on the bench. Never extend a balance lead past 50 cm, or readings drift.
How do you build your own JST-XH leads?
A 500-piece JST-XH kit gives housings, crimp terminals, and pin headers in 2 to 6 pins. It builds leads for any cell count.
Crimp each terminal with a proper JST crimper, then push it into the housing until it clicks. Tug each wire with 1 kg of force to test the crimp.
Frequently asked questions
Can I charge a LiPo without a balance lead?
No. Always balance charge LiPo packs. A charger without a balance lead cannot see a single high cell.
What voltage is a full LiPo cell?
A full LiPo cell reads 4.20 V. A 2S pack reads 8.40 V, and a 6S pack reads 25.20 V at full charge.
Do all balance plugs use JST-XH?
Most RC packs use JST-XH, but some use JST-EH or Molex plugs. Check the plug shape before you order adapters.
How do I know if a balance lead is worn?
A worn plug feels loose and gives jumpy cell readings. Swap in a connector saver before the pack plug fails.
Parts used
JST-XH 1S-6S Balance Extension Leads, 20cm, 5 Pieces, $7.37. JST-XH LiPo balance extension leads, 20cm of 22AWG wire. Makes balance charging easier. Pack of 5, 1S through 6S. Ships from NY, USA.
2S JST-XH Balance Connector Saver, 5-Pack, $4.50. Five 2S JST-XH balance connector savers. A bigger grip that makes plugging and unplugging safer on your battery leads.
4S JST-XH Balance Connector Saver, 5-Pack, $4.50. Five 4S JST-XH balance connector savers. A bigger grip that makes plugging and unplugging safer on your battery leads.
JST to JST-XH Balance Adapter Set, 2S-6S, $5.99. Balance adapter set from JST male to JST-XH, covering 2S through 6S. 20AWG wire. Lets odd-plug packs charge on a standard balance charger.
JST-XH 2.54mm Connector Kit, 500pcs – Housings + Crimp Terminals + Pin Headers, 2/3/4/5/6-Pin, $12.72. 500pc JST-XH 2.54mm kit : housings, crimp terminals, and pin headers in 2/3/4/5/6-pin. Build your own leads. Ships from NY, USA.
XT60H Male + Female Connector Set with Sheath Housing, 10-Pair, $11.87. XT60H male + female bullet connector set with sheath housing : gold-plated copper, 60A max. 10-pair. Ships from NY, USA.
XT60 Extension Cable, 14AWG, $6.31. XT60 connector pigtail with 14AWG silicone wire. Gold-plated contacts, rated 30A. Choose male or female, length, and quantity. Ships from NY, USA.
XL4015 5A DC-DC Step Down Buck Converter Module, 4-38V to 1.25-36V, 2-Pack, $7.41. XL4015 5A DC-DC step-down buck module : 4: 38V in, adjustable 1.25: 36V out. 2-pack. Ships from NY, USA.
B6 80W Digital Balance Charger, T/Tamiya/XT60 Plug, $49.99. Imax B6 80W digital balance charger for LiPo, NiMH, NiCd, and Li-ion packs. Includes T-plug, Tamiya, and XT60 charge leads. Ships from NY, USA.
LiPo Low Voltage Buzzer Alarm + Battery Voltage Indicator Tester, 1S-8S, $4.85. LiPo low-voltage buzzer alarm + voltage tester for 1S: 8S packs : buzzer + red LED when any cell drops below your set threshold. Single unit. Ships from NY, USA.
Related buying guides on Quality RC Parts
How to Choose JST and Balance Connectors for RC Packs
How to Balance Charge a LiPo Battery With an Adapter Cable
How to Choose Connectors and Wiring for Your RC Build
Browse all the guides on the Quality RC Parts Drone Guides hub, or start at the Quality RC Parts store.
Sources
- Battery University: Series and parallel battery configurations
- PowerStream: Wire size and ampacity
- SparkFun: How to solder through-hole soldering
Quality RC Parts stocks parts in New York, USA and ships in-stock orders in 1-2 business days.
Last updated: 2026-11-10.