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48V battery: how many cells? Voltage to S count chart

Short answer: a 48 V pack is 13 cells in series (13S), so the cell count is 13 × P — 39 cells for 13S3P, 52 for 13S4P, 65 for 13S5P. The voltage tells you the S number and nothing else; the capacity you want tells you the P number.

Short answer: a 48 V pack is 13 cells in series (13S), so the cell count is 13 × P — 39 cells for 13S3P, 52 for 13S4P, 65 for 13S5P. The voltage tells you the S number and nothing else; the capacity you want tells you the P number.

The confusion is that motor and controller listings advertise voltage while battery listings advertise configuration. Both describe the same thing. Here is the conversion:

Nominal voltageSeries countFull charge (4.2 V/cell)Where you see it
36 V10S42.0 VOriginal and commuter e-bikes
48 V13S54.6 VThe dominant modern voltage; most conversion kits
52 V14S58.8 VHigher-performance conversions, some cargo bikes
60 V16S67.2 VFast commuters, heavier cargo
72 V20S84.0 VHigh-power builds, some tricycles

Our own housings are rated across 36 V to 72 V, because the case is an empty shell — it does not care about the voltage, only about whether the cell block and the BMS fit inside it. That is worth stating plainly: a housing has no electrical rating at all. What varies across the range is capacity, and that is a physical question.

Why 48 V became the default

Almost every conversion kit sold now is 48 V, and it is the voltage our range is most often specified for. The practical consequence for anyone ordering a case is that 13S is the series count to plan around, and 13S boards are longer than the 10S boards that most moulds in this industry were drawn against — which is the origin of a great many fitting problems.

What the voltage decides about your case

  • The BMS length. 13S and up needs more internal length than the 10S figure on the drawing. Budget 30–50 mm above the 10S allowance, plus mounting space.
  • The number of cell groups. 13 groups of cells, laid out to suit the housing's interior rather than in a straight line, so the shape of the block is determined by the format.
  • Nothing else. Cable exits, mounting points and shell material are the same at 36 V and 72 V; the shell does not know the difference.

Working back from the voltage to the case

Take your voltage, convert it to S, decide the P from the range you need, then check the two independently. A 48 V (13S) pack at 4P is 52 cells — that will sit inside any of the larger downtube or Hailong moulds. The same 48 V at 6P is 78 cells and needs a mid-size housing or above. On 21700 the arithmetic is identical but the interior takes roughly 30 % fewer cells: a Hailong-pattern case that holds 117 on 18650 holds 80 on 21700.

The voltage comparison lists what each voltage implies for housing choice, or go straight to the case selector with your numbers.

Common questions

How many cells are in a 48V battery?
48 V nominal means 13 cells in series, so the total is 13 × P. 13S3P is 39 cells, 13S4P is 52, 13S5P is 65, 13S6P is 78. The voltage fixes the series count only.
How many cells is a 48V 13Ah battery?
It depends on the cell capacity. At 3 500 mAh per cell, 13 Ah needs 4 cells in parallel, so a 48 V 13 Ah pack is 13S4P — 52 cells. At 2 500 mAh it would be 13S6P, 78 cells.
Is 48V 13S or 14S?
13S. 13 × 3.6 V = 46.8 V, which is labelled 48 V. 14S is 50.4 V and is labelled 52 V.
Does a battery case have a voltage rating?
No. An empty housing has no electrical rating — it is a shell. What varies is how many cells of each format fit inside it and whether there is room for the BMS. Our range is used across 36 V to 72 V builds without any change to the mould.
How many cells in a 72V battery?
72 V nominal is 20S, so the total is 20 × P: 100 cells at 20S5P, 160 at 20S8P. That size needs a large rack or cargo housing rather than a downtube one.

Send us the pack and we will confirm the fit

Cell type, series and parallel count is usually enough. If the answer is that none of our moulds fit, we will say so rather than sell you the nearest thing.