36V Lithium Battery Packs

36V = 10S: the configuration basics

A 36V lithium-ion pack is a 10S pack: ten cells connected in series set the nominal voltage class. That is the definition an OEM engineer works from when specifying a li ion battery pack 36v, and it is the starting point for every 36V project we quote. Series count fixes the voltage; capacity comes from the parallel count and the cell chosen.

The series string is not negotiable once 36V is set, but almost everything else is. Parallel count, cell model, BMS topology, enclosure format and connector type are all project decisions. Two 10S packs can share a voltage class and behave very differently on a load profile, which is why the specification starts from your device rather than from a standard part number.

Because the configuration is fixed at ten series cells, the practical engineering work sits in the parallel branch. Move from a 2P to a 5P build and the pack gains capacity and current headroom, but it also gains mass and volume. Each step is checked against the space the device actually has and the current it actually draws.

Documented 10S reference designs

Our specification library carries two 36V reference builds: 10S2P 4.4Ah and 10S5P 12Ah, the latter documented as an e-bike configuration. These are real configurations from past projects, not catalogue stock, and they show the range a 10S platform covers when the parallel count changes.

The 10S2P 4.4Ah build suits compact devices where energy demand is modest and weight matters. The 10S5P 12Ah e-bike configuration sits at the other end of the same voltage class, trading size for range and current capability. Between them they frame the design space a 36V project usually occupies.

Custom capacities are built by adjusting the parallel count and cell choice per project. If neither reference build fits, the specification is written around your target capacity, discharge profile and mechanical envelope, then confirmed with you before tooling or assembly begins. The reference designs shorten the conversation; they do not limit it.

Cell selection drives much of that decision. The 18650 format is a common building block for 10S work, and our 18650 battery packs page covers how those cells are specified and assembled. Where a project needs a different format or a higher-voltage platform alongside the 36V pack, the 10S design rules still apply — only the series count changes.

36V packs for e-bikes, light EVs and equipment

36V packs are built for e-bikes, light EVs and equipment, and each of those three applications stresses the pack differently. An e-bike pack sees pedal-assist load patterns and a mounting envelope inside the frame. Light EV packs face deeper discharges and higher continuous currents. Equipment packs often prioritise a stable fit inside a fixed housing over energy density.

That is why the same 10S platform produces different packs. On the e-bike side, the 10S5P 12Ah reference build shows how a 36V configuration is documented when range and current headroom both matter. For light EV work, the pack is specified against the vehicle's controller limits and duty cycle; our light EV battery packs page sets out how those projects are scoped.

Equipment applications tend to bring the tightest mechanical constraints. A pack that fits the housing but sags under load is a failure, and so is one that meets the current demand but will not seat. Both are resolved at the specification stage by checking the proposed 10S layout against the drawing you supply.

Voltage class is a separate decision from application. Some platforms run a higher series count for the same device family, and the design logic carries across; the 48V lithium packs page covers the higher-voltage equivalent. If you are weighing 36V against another class, the current profile and charger architecture usually settle it before capacity enters the discussion.

Documentation is handled per model. UN38.3, IEC 62133 and MSDS documents can be confirmed and provided for specific models; tell us the model you are buying and we will confirm which documents cover it. This applies to reference builds and custom configurations alike, because the document set follows the exact pack, not the voltage class.

When you are ready to spec a 36V pack, bring the device drawing, the current profile and the target capacity. Those three inputs are enough to select a parallel count and cell, match it to a reference design or start a new one, and confirm which documents will cover the finished model.

Frequently Asked Questions

What 10S configurations are available at 36V?

Two documented reference designs are 10S2P 4.4Ah and 10S5P 12Ah, the second built as an e-bike configuration. Beyond those, custom capacities are built by adjusting the parallel count and cell choice per project, so the available configurations follow your capacity, current and space requirements rather than a fixed list. The series count stays at ten; the parallel branch is where the specification moves.

Do you build 36V packs for e-bikes and light EVs?

Yes. 36V packs are built for e-bikes, light EVs and equipment, and the 10S5P 12Ah reference design is documented as an e-bike configuration. Light EV projects are specified against the vehicle's controller limits and duty cycle, with the mechanical envelope checked against your drawing. Equipment builds follow the same 10S rules with the housing constraint treated as the primary limit.