Surlon Power NCM | 36V14Ah E-bike battery

Product Overview

The Surlon Power EB05 is a 36V 14Ah NCM battery pack built for e-bikes that need dependable, frame-mounted energy without excess bulk. Its cells are arranged 10S4P and store 504Wh — a reserve that covers a daily commute, a weekend endurance ride or a full shift on a rental bike without the rider watching the gauge every few kilometres.

We supply this pack to three kinds of buyer. E-bike makers fit it to a new model that has settled on a 36V system. Workshops and retrofit shops use it to replace a tired pack on a bike already in service, in a Hailong-format housing designed to sit in the matching frame cradle. Rental and share operators standardise on one format so packs can move between bikes without retraining staff. In each case the pack slides into its cradle and locks, which keeps installation familiar for the people who build or service the bike.

NCM chemistry is why the pack stays light for what it stores. Nickel-cobalt-manganese cells hold more energy per kilogram than the LiFePO4 cells behind our floor scrubber, golf cart and SLA replacement ranges. On an e-bike that difference shows up in handling: weight carried high on the downtube changes how a machine steers, climbs and feels over rough ground.

This is one model in a wider e-bike and light-mobility line that also includes LiFePO4 packs and our own BMS boards, so a project that later moves to a different voltage or chemistry does not have to start over with a new supplier.

Housing, Ports & Display

• Aluminium 6061 + PC + ABS shell. The body combines a metal structure with moulded polymer sections, so the pack resists knocks and stays rigid in the cradle while keeping weight down. The finish is a consistent matte black, which matters when a fleet wants packs to look the same across mixed bikes.
• A dedicated charging inlet. Charging happens through its own port rather than through the discharge connection, so a pack can be topped up on a bench with the bike's loom disconnected.
• A separate discharge port. Output to the controller runs through its own connection, which keeps the high-current path away from the charging circuit and makes diagnosis simpler when something is wrong.
• Integrated USB port. A small accessory port on the housing lets a rider top up a phone, a bike computer or a light while out. The draw is modest against the pack's capacity, but it comes out of the same energy budget, so plan for it on long days.
• Battery level display. The indicator on the housing shows roughly how much charge is left without plugging anything in — useful at handover for rental staff and before a long ride for private owners.
• Cylindrical body with rounded ends. The shape follows the cradle geometry this format is built around, so it slides in without forcing or shimming.
• Port layout can be customized. The USB position and port arrangement can be changed for a production programme, so the housing matches your frame and your accessory expectations rather than the other way round.

Fit & Wiring Check

Start with the drawing, not the label. Compare the pack's length, height and width in the specification with a measured drawing of your compartment, and leave room for the cradle rails, the locking mechanism and the cable bend at the discharge end. A pack that fits the opening but pinches the cable will fail at the connector long before the cells wear out.

The two port definitions tell you what has to mate. Charging-port wiring is DC2.1 and discharging-port wiring is 3pin, so check the plug on your charger against the first and the plug on your controller cable against the second. Pinout and polarity matter as much as the shape: a 3pin connector wired in a different order is not the same connector. If your bike uses something else, tell us at the enquiry stage rather than adapting the wiring afterwards.

The controller has its own expectations. It must be a 36V nominal system, and its low-voltage cut-off should agree with the pack's discharge cut-off — if the controller keeps pulling after the pack has reached its limit, the bike will cut out under load and the cells will be worked harder than they should be. The charger has to respect the charging limit voltage as well, which is why we ask for the charger model before a sample is agreed.

As a 36V lithium battery for electric bikes, this pack has to match more than a voltage number. Send a photo of the compartment, the old pack's label, the controller plug and the charger label, and we will confirm whether the standard build fits or whether the housing, connector or wiring needs a variant.

Cell Selection & Quality Control

• One roof, start to finish. The pack is developed and assembled in our own lab and factory in China, from the first project drawing to the finished unit, so the people who tested the cells are the people who sign off the pack.
• Cells chosen on internal test data. We benchmark suppliers against our own tests, then test and select incoming cells before they go into a build. A cell that drifts under load does not reach assembly, whatever its price.
• Matched before assembly. Cells are graded and grouped so the parallel strings in a pack behave alike from the first cycle, which is what keeps the pack balanced as it ages instead of leaning on one group.
• Six-step electrical and mechanical control. Every battery goes through a six-step electrical and mechanical quality routine before release, covering the build as well as the finished unit rather than a single end-of-line check.
• Declared standards. We build to the standards declared for this model, including CE, UKCA, UN38.3 and IEC 62133-2:2017.
• The same routine for custom work. A custom e-bike battery pack is a new combination of cells, connector, housing and BMS settings, so the checks apply to the first sample exactly as they do to a repeat order.
• Documents follow the revision. Ask for the reports and declarations that belong to the revision you approve, and keep them with your technical file — a document for a different revision does not cover your build.

Battery Management & Protection

The pack carries a built-in 30A battery management system, mounted inside the housing with the cells. It watches what the pack is doing while the bike is ridden and steps in before a fault becomes damage: over-voltage and overcharge on the way in, deep discharge on the way out, over-temperature when the motor works hard or the day is hot, and short circuit if a cable or connector fails.

Balancing is the quieter half of the job. The system keeps the series groups at the same voltage, so usable capacity is not lost because one group drifted away from the rest. That is the difference between a pack that still delivers close to its rated energy after a couple of seasons and one that sags early and gets blamed on the motor.

A low-voltage switch lets the output be isolated, which is useful when a pack is taken out of service, stored or moved between bikes. Riders should not have to think about any of this; the value is that the protection is already working when a controller asks for current on a climb.

One practical rule for workshops: if a pack has tripped protection, find the cause before resetting it. Repeated resets hide a wiring fault, a failing charger or a weak cell group, and the next trip may not be so forgiving.

Sustained Power Output

• Parallel strings share the load. Current is divided across the parallel cells in each group, so no single cell carries the whole demand. Less heat per cell means output holds on a long climb instead of fading halfway up.
• Headroom above normal riding current. The pack's maximum discharge rating sits above what the motor draws in ordinary use, so acceleration and steep gradients do not sit permanently against the protection limit.
• Steady assist as the charge drops. Because the load is shared across the parallel groups, voltage stays closer to nominal through the middle of the discharge, so assist feels similar rather than tapering off early.
• Thermal and mechanical design in the housing. The case is laid out to move heat away from the cells and to hold them firmly, which matters on cobbles, kerbs and rough cycle paths as much as on a hill.
• Consistent unit to unit. For a fleet or a test bench the point is repeatability: the same controller, the same motor and the same rider get the same response from every pack of the model.
• Nothing to top up. There is no electrolyte to check and no acid film to clean off the terminals, unlike the lead-acid packs some riders are coming from.
• For a 36V lithium battery for electric bikes, output is the whole point. A pack that protects itself too early feels weak; one that never limits overheats. Getting that balance right is what lets a rider use the motor's full assist on the steepest part of the route.

Range & Riding Modes

The range figures for this pack are favourable-case numbers on a favourable route: up to 70 km on a charge when the bike is ridden gently in ECO, and up to 50 km when it is ridden hard in TURBO. The battery has not changed between those two numbers — what changes is how often and how hard the motor asks for current.

Read both as a comparison rather than a promise. Rider and luggage weight, hills, headwind, ambient temperature, tyre pressure and the number of stops all move the figure, and a cold morning takes a noticeable bite out of it. Stop-start city riding is harder on a pack than a steady towpath, and a loaded utility bike is harder again.

For planning, work from the lower number. A commuter who knows the round trip and the terrain can decide how much assist to spend each way; a fleet can set shift lengths around the TURBO case and treat the ECO figure as the generous end of the envelope. It is also worth telling riders which mode the figure refers to, because most range complaints come from a number quoted without its conditions.

Specification

Where This Pack Fits

• New e-bike builds. Manufacturers who have settled on a 36V system and need a pack that drops into a standard cradle without redesigning the frame around it.
• Replacement and retrofit. Workshops replacing an ageing pack on a bike already in service — the 36V 14Ah NCM battery pack is a straightforward like-for-like swap once the cradle, connector and charger have been checked.
• Rental and share fleets. One format across the fleet means packs can be swapped between bikes, and the level display makes handover checks quick at the start of a shift.
• R&D and test benches. Engineering teams benchmarking a controller, motor or drive unit need packs that behave the same way each time they are fitted to the rig.
• Commuter and light utility bikes. Builds that carry a rider, a rack or light cargo and work the motor harder than a leisure bike ever will.
• Distributors and importers. A widely used 36V format worth stocking for local workshops, instead of holding a dozen near-identical variants.

Charging & Storage Routine

1. Match the charger before the first charge. Its output has to respect the charging limit voltage and stay within the charging current this pack accepts; if you are unsure, send us the charger label and we will tell you.
2. Charge at room temperature. The pack has a defined charging range, and charging one that has just come in from freezing — or leaving it in direct sun while it charges — is harder on the cells than charging indoors.
3. Top up after rides instead of running the pack to empty. Shallow charges suit this chemistry better than deep ones, and the level display makes it easy to see where you stand.
4. Store it part-charged. For a winter lay-up, leave the pack with roughly half a charge in a cool, dry place rather than full or flat, and keep it away from frost and direct sun.
5. Recharge during storage. A pack that sits for months should be topped back up periodically so it does not drift into a deeply discharged state.
6. Keep the ports dry and the contacts clean, and never open the housing. Treat this 36V lithium battery for electric bikes like any lithium pack: a damaged or swollen unit should be taken out of service, not charged again.

Ordering & Confirmation

• Send the application, not just a voltage. A frame or compartment drawing, the controller and charger details, connector photos, the quantity you expect and the destination market give us enough to propose a configuration instead of a guess.
• Agree the revision before the sample. You receive the drawing and specification for the exact revision being built, and that document is what the sample and the production order are checked against.
• Samples. Ask your sales contact about sample availability and the schedule for your configuration.
• Packing and transport. Lithium batteries travel with the transport documentation the shipping mode requires; tell us the destination and whether the packs go by air, sea or road so the paperwork matches.
• Terms per project. Price, lead time, packing, payment terms and warranty are quoted for your quantity and destination — confirm them with your sales contact before you build a launch plan around them.
• Custom work starts here too. If this model is close but not exact, the same information is what we need to quote a custom e-Bike battery pack around your frame, controller and charger.

Battery Chemistry Choice

The chemistry decision should follow the bike's duty, not the other way round. NCM is the reason this 36V 14Ah NCM battery pack stores 504Wh in a 4 kg housing: nickel-cobalt-manganese cells hold more energy per kilogram, so the pack stays light enough for a frame-mounted bike to steer and climb well. For a commuter, rental or retrofit bike where range and handling matter more than many seasons of cycling, that weight advantage is the practical reason to choose NCM.

LiFePO4 belongs in the conversation when cycle life and tolerance of deep, frequent discharge outweigh weight. Our LiFePO4 packs for floor scrubbers, golf carts and SLA replacement service are built around exactly that trade-off: heavier for the same capacity, but happier with daily hard use. An e-bike fleet that runs several shifts a day and can accept a larger, heavier pack may find the longer service interval worth it; a consumer-style bike with a fixed downtube cradle usually cannot.

Work through four questions before settling on a chemistry. What does the frame or cradle allow in length, width and height? How many charge cycles will the bike see in a year, and how deep will each discharge be? Will the pack live in a cold workshop or a hot van? And what charger and controller are already fixed in the design? A 36V nominal system can be built in either chemistry, but the voltage window, charging profile and BMS settings differ, so the pack has to be specified as a complete system rather than swapped by label.

The paperwork follows the same logic. NCM and LiFePO4 cells do not behave the same in a pack, so the BMS settings, charging limits and transport documentation are raised for the actual configuration you approve. If your project may later move to a longer-life chemistry, tell us at the sample stage: we build both chemistries in-house and can compare them against your frame, load profile and expected annual distance before you commit a production order.

Reliability and Performance in Every Situation

Inside a durable, sealed housing we've enclosed more than just high-quality cells built for a long service life. A microprocessor-controlled battery management system constantly monitors the battery's operating parameters and provides all the protections that keep your rides safe, including protection against deep discharge, overcharging and overheating. It also balances the voltage between cells to extend battery life. The built-in 30A BMS is a high-output source of energy for your bike's motor, so you keep maximum performance even on the steepest climbs and use 100% of your e-bike's potential.

Technical Support & Model Matching

Technical questions reach the people who build the packs. Our engineering group in Shenzhen reviews your device's voltage window, load profile, enclosure space and charger before proposing a configuration; our sample group then builds units so you can validate fit and runtime before production. Cell selection, BMS design and pack assembly stay in-house, with quality checks in process and at final inspection, and a documentation team handling certificates, test reports and shipping papers. When a unit behaves unexpectedly in the field, our engineers help trace the fault and advise on installation and commissioning.

FAQ