Built for small, low-voltage luminaires
This pack brings two LiFePO4 cells together in a 2S1P arrangement inside a PVC wrap, with a protection circuit on board and a three-wire lead set that carries power out and temperature information back to the fixture. The result is a slim cylinder that drops into a lamp head or a pole-mounted battery bay where a lead-acid block would simply never fit.
Most enquiries come from lighting manufacturers who need a 6.4V battery pack for solar street lights, garden posts or emergency heads, and from distributors who keep those fixtures running in the field. The same pack also serves small backup equipment — control boxes, access devices and standby heads that need a dependable block on the far side of a charger.
Why LiFePO4 at this size
Lithium iron phosphate holds its voltage across most of the discharge curve and has no liquid electrolyte to top up and no memory effect to manage. In a fixture that is sealed for years, that removes the topping-up routine a small lead-acid block demands and the memory habits that shorten nickel-cadmium packs.
How it arrives
Every unit is wrapped, with the lead set terminated and the thermistor already wired into the plug. There is nothing to assemble on the bench: the pack goes into the bay, plugs into the fixture loom, and is held by the housing's own bracket or by an adhesive pad.
What to prepare before you ask for a quote
Have the device voltage window, the charging profile, the compartment dimensions, the connector pinout and the load current to hand. Those five details decide whether this rating, a different capacity, or a different lead arrangement is the right answer — and they are what our engineers review first.
Two cells rather than one
If you are weighing a two-cell pack against a single-cell design, the difference is headroom. Two cells in series give the higher rail that many LED drivers and small controllers expect, without adding a boost stage that costs efficiency and board space.
| Parameter | Specification |
|---|---|
| Nominal voltage / capacity | 6.4V / 3.6Ah (C5); minimum 3.45Ah (C5) |
| Energy / configuration | Approx. 23.04Wh / 26FC-2S1P |
| AC internal resistance | ≤140mΩ |
| Dimensions | (135 ± 2) mm × Ø(29 ± 2) mm; excludes leads and connector |
| Weight | 190 ± 20 g |
| Charging | 7.2 ± 0.1V; maximum charge current 0.72A; cutoff current 36–72mA |
| Discharging | Current ≤3A; end voltage about 5.0V |
| Operating temperature | Charge: 0–50°C; discharge: −20–60°C |
| Protection circuit | Overcharge and overdischarge protection |
| Connector | JST-XH-3P, 20AWG; 105 ± 10 mm including plug. Red: positive; black: negative; yellow: NTC. |
| Pin assignment | Red: positive; black: negative; yellow: NTC |
| Cell chemistry | LiFePO4 |
| Marking note | Some older catalogues list this model as a 6.4V 33.6Ah LiFePO4 battery; the rated capacity is 3.6Ah at the five-hour rate |
Charge retention
Under the specified test conditions the pack keeps at least 85% of its charge after 28 days off the charger. That detail matters more than it sounds in lighting: a street light or an emergency head can sit for weeks between meaningful charge cycles, and a pack that bleeds energy while idle leaves the fixture short on the first dark night after commissioning.
Cycle life and what it is measured against
The pack is rated for at least 2,000 cycles with at least 80% capacity retention, measured with the standard charge and discharge procedure in the manual. Real service life depends on how deeply each cycle runs, at what temperature, and at what charge rate, so read the figure as a bench reference and match the charger and duty cycle to what your fixture actually does.
Temperature protection settings
Set the charge temperature protection to no more than 55 °C and the discharge temperature protection to no more than 60 °C, as the manual specifies. In a lamp head that already runs warm in summer, this is the layer that stops the pack being charged while the electronics are hot.
Five checks before integration
Confirm the device voltage window, the charging profile, the available dimensions, the connector pinout and the load current. Any one of them can turn a near-match into a field problem: a pack that fits the bay but sits behind a charger with the wrong end-of-charge behaviour will disappoint outdoors, not on the bench.
Project-specific fit
Where the standard lead length, plug or capacity does not quite suit your housing, our engineers review the fixture drawing and propose a configuration. Send the compartment sketch and the charger details with the first enquiry so the review starts from real constraints instead of assumptions.
What the figures cannot tell you
Rated capacity and cycle count describe the cells, not your product. Runtime in your lamp depends on driver efficiency, dimming profile, night length and how much of the discharge window you allow. Agree a runtime target with us and validate it on an evaluation unit in the real fixture before you commit a production batch.
Use a charger that knows LiFePO4
A small lead-acid charger will not do. Its absorption and float stages follow a different voltage curve, and a nickel-cadmium charger is further off still. Choose a two-cell LiFePO4 charger, or a solar controller with a LiFePO4 setting, and set its output to the charging window in the specification table above.
End-of-charge behaviour matters as much as the voltage
The charger should finish its constant-voltage stage at the defined cutoff current and then stop, rather than holding the pack at full voltage indefinitely. Maintained emergency heads sit on charge for months at a time, and a charger that never terminates is the quickest way to shorten that relationship.
Keep the charge current modest
This is a small pack, and a gentle overnight charge suits a street light or an exit sign far better than a fast top-up. Slower charging also keeps cell temperature down inside a sealed housing, which is where the cycle-life figure is won or lost.
Respect the temperature limits at both ends
Charging has a cold limit and a hot limit. In a cold-climate installation the controller has to hold off charging until the pack has warmed; in a roof-mounted head it has to stop before the electronics cook the cells. Both behaviours belong in the charger or controller logic rather than in the hope that the weather cooperates.
The protection circuit is a backstop, not a charger
The overcharge and overdischarge circuit protects the cells during a fault. It is not there to manage normal charging, and with the charger set correctly it should never need to act.
Wire the solar system as one system
In a solar street light the panel, controller and pack work together, and the 6.4V battery pack for solar street lights is only as good as the controller charging it. Confirm the controller's LiFePO4 profile, its low-temperature behaviour and its load-disconnect point against the pack before the first night, and check that the light's standby consumption does not quietly drain the pack between charges.
The pack is marked 6.4V3.6Ah and carried in our lighting range as model LB05. When you are replacing a block in an existing fixture, read the marking on the unit you remove rather than the marking in a catalogue — that label is the one the fixture was designed around.
Some older datasheets and pack markings in this family read 6.4V 33.6Ah LiFePO4 battery. This model is rated 3.6Ah at the five-hour rate, with a 3.45Ah minimum, so if your document shows a much larger figure, send it to us with a photo of the old pack and we will tell you which build you actually have in front of you.
Capacity is only one line on the label. A replacement also has to match the plug type, the pinout, the lead length and the charger behind it. Two packs can share a voltage and a capacity and still not interchange, because one carries a thermistor in the plug and the other does not.
Send the label photo, a photo of the connector, a sketch of the compartment with the lead exit marked, and the charger model. From those four items we can usually confirm whether the standard build fits, or whether a modified lead or connector is the honest answer.
If the fixture needs more runtime than the original block delivered, a higher-capacity build is worth discussing. If it only needs a replacement, staying with the same rating keeps the charger, the bay and the approval file unchanged — usually the cheaper route.
| Document | What it covers |
| Model drawing | Available on request — outline dimensions, lead exit, connector orientation and marking position |
| Specification sheet | Available on request — electrical ratings, test conditions and the revision they belong to |
| Life-test conditions | Available on request — charge and discharge conditions behind the published cycle and retention figures |
| Handling and installation notes | Available on request — charging, temperature limits and fitting guidance for the pack |
| Transport documents | Available on request — the papers required for lithium battery shipments to your destination |
| Label artwork | Available on request — marking and branding agreed for a custom lighting battery build |
Technical questions reach the people who build the packs, including what to do when a drawing or an old label says 6.4V 33.6Ah LiFePO4 battery. 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.
Only after the fixture has been checked against it. The pack has to sit inside the driver's voltage window, the charger has to suit a two-cell LiFePO4 pack rather than a lead-acid profile, and the plug, pinout and compartment have to line up. Send the label from the old pack, a photo of its connector and the charger model, and we will tell you whether the standard build fits or whether a modified lead is needed. Matching the nominal voltage on its own is not enough to call something a replacement.
It carries the NTC thermistor, which lets a charger or controller read the pack's temperature. If your driver has no input for it, leave the lead isolated and stowed so it cannot touch either power rail — do not trim it back into the wrap and do not short it. Fixtures that charge unattended, such as maintained emergency heads and solar street lights, are worth wiring it up: it is what allows the charger to slow down or stop when the pack runs hot or cold.
Divide the rated capacity by the average current your fixture draws, then discount the answer. Usable energy runs out before the cells are completely flat, cold weather trims capacity, the driver takes its share, and a pack in a solar street light only gets the charging hours the weather allows. Send us the load current, the dimming profile and the required night run, and we will work through the estimate with you rather than hand over a number that will not survive the first winter.
Those are the usual reasons a custom lighting battery gets built. Send the connector part number or a clear photo, the lead length you need, the capacity or runtime target, and the compartment drawing. We review the request against the pack's electrical limits and come back with a proposed configuration; the evaluation unit is then made to that drawing so you can fit it in the real housing before committing to a batch.
3.6Ah is the rated capacity at the five-hour rate, and 3.45Ah is the minimum a pack may deliver under the same test. The gap covers normal cell-to-cell variation, so a unit at the lower end is still within specification. Size your runtime on the minimum figure rather than the headline rating — that is the number the fixture has to live with.
