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13S9P battery case — 117 cells, 48 V

A 13S9P pack is 117 cells: 13 groups in series, 9 in parallel in each group. This page lists the 21700 housings that actually take it, in the order of how much room they leave for the BMS and the wiring.

Short answer: 2 of our 110 housings take a 13S9P on 21700. 2 of those leave at least six cells of room — which is the practical minimum once a 13S BMS and the wiring are in.

The pack, in numbers

Cells117
Nominal voltage13 × 3.6 V = 48 V
Charge voltage13 × 4.2 V = 54.6 V
Capacity (typical)9 × 5.0 Ah = 45.0 Ah
Energy (typical)2106 Wh

Capacity assumes 5.0 Ah per 21700 cell. Your cells will differ — the cell count and the voltage are exact, the capacity is a working figure.

Housings that take it

Model21700 ceilingRoom left
ALX136D · Silver Fish16043
ALX178 · Downtube16043

Why room left matters more than the ceiling. A housing listed at 117 cells holds your pack exactly and nothing else — no BMS, no nickel, no cable exit. In practice a 13S pack needs roughly six cells of space beyond the cells themselves, because a 13S BMS is longer than the 10S board these moulds were designed around. That is the single most common reason a build that “fits” does not close. There is a longer explanation in why your 13S5P pack will not fit.

Work out your own configuration

The pack calculator does this for any series and parallel count, and the case selector takes a plain cell count if you already know it.

What 2106 Wh actually gets you

The figure above is energy, not distance. A 13S9P pack on 21700 works out to about 2106 Wh, which is roughly 176–263 km on low assist and 66–96 km at full assist for a 75 kg rider on mixed terrain. How far a pack will take you explains what moves that figure, and how the same configuration on the other cell format compares.

Other configurations

The parallel count is what changes the housing, not the series count.

Common questions

How many cells is a 13S9P pack?
117 cells — 13 groups wired in series, 9 cells in parallel in each group.
What voltage is 13S?
48 V nominal (13 x 3.6 V), charging to 54.6 V.
Which battery case takes a 13S9P pack on 21700?
2 of our housings take it. 2 leave at least six cells of room for the BMS and wiring.
Can I use a 13S9P pack in a case listed at fewer cells?
No. The listing is the ceiling. If a housing says it takes 114 cells it will not take 117.

Send us the pack and we will confirm the fit

Cell format, series and parallel count is usually enough to answer the same day. If the answer is that none of our moulds fit, we will say so.