Custom battery manufacturing
How long does a custom battery pack take to develop?
Typical projects run from a few weeks for standard configurations to several months when new tooling, testing or certification is involved. Ask for a dated milestone plan at RFQ stage.
What is the minimum order quantity (MOQ) for custom packs?
Many manufacturers accept small prototype quantities for testing, then require larger volumes for mass production. Discuss prototype MOQ and production MOQ separately.
How many prototype rounds are normal?
One to three. Mechanical fit issues and firmware tweaks usually get resolved in the first two rounds.
Who owns the design and tooling?
Agree at contract stage: buyer-owned design with a manufacturer NDA, or manufacturer-owned reference designs reused across projects.
Can you build LiFePO4 packs as well as NMC?
Yes. XINYUEGE designs and manufactures both Li-ion (NMC) and LiFePO4 packs. NMC suits weight- and size-sensitive devices; LiFePO4 suits applications where cycle life and safety matter more.
Battery pack design
What does 2S2P mean?
Two cells in series, in two parallel strings: 7.2V at twice the single-cell capacity.
Does parallel increase voltage?
No. Parallel keeps the same voltage and adds capacity and current; only series adds voltage.
How many cells do I need for a 48V 20Ah pack with 21700 cells?
13S for voltage. With 4.8Ah cells, 20Ah needs 4P (19.2Ah) or 5P (24Ah) — roughly 52–65 cells depending on the exact cell capacity.
Can I mix 18650 and 21700 cells in one pack?
No — never mix different cell models or formats in one pack. Different internal resistance, capacity and ageing behaviour create imbalance and safety risk.
Which cell format is better for a custom e-bike battery?
21700 is the mainstream choice today: higher energy per cell and fewer weld points. 18650 remains valid for cost-optimised designs.
Are prismatic cells safer than cylindrical?
Both are safe when properly designed. Safety comes from the whole system — cells, BMS, enclosure, testing — not the shape.
E-bike battery replacement
Can I install a higher-capacity battery than the original?
Yes, if the voltage class and connector match and the pack physically fits — higher Wh means longer range. Check BMS/controller current compatibility first.
Can I upgrade a 36V bike to 48V?
Only if the motor controller supports 48V input. If it is a 36V-only controller, do not overvolt it; replace the controller as a system.
Why does the display show nothing with the new battery?
Usually a BMS communication mismatch (UART/CAN protocol) or a wiring fault. Confirm the BMS protocol matches the display and controller.
Shipping and certification
How long does a UN38.3 test take?
Typically a few weeks for a straightforward pack design, including lab scheduling. Plan it into the project timeline; it cannot be rushed.
Can samples ship by air?
Yes, with the same UN38.3, MSDS and state-of-charge rules as production goods — samples are not exempt.
Do I need my own dangerous-goods training?
Someone must sign the dangerous-goods declaration and know the rules — either your trained staff or the freight forwarder’s.
What does UN38.3 cover?
Eight transport-safety tests on the exact cell and pack design: altitude, thermal cycling, vibration, shock, external short circuit, impact/crush, overcharge and forced discharge.