Battery Options

Battery Options

Our current lineup covers downtube, triangle, and bottle packs plus the stackable LiGo 10X, all made with premium Panasonic, LG, or Samsung cells. Most use Anderson Powerpole connectors on the discharge lead and an ST3 port for charging at up to 8 amps, with a robust BMS circuit for overcharge, over-discharge, and overcurrent protection. Every pack is individually discharge-tested at Grin before it ships, so the capacity on the label is the capacity you actually get.

LiGo 10X Built for riders who want to travel or fly with their ebike. Each LiGo 10X module is 36V 2.75Ah, just under 100 watt-hours, which keeps it under the Dangerous Goods limit and even lets it ride in carry-on baggage. Parallel-connect as many modules as you need for capacity, or series-connect them for a 72V setup. Designed and made in Canada, it is also our only pack that ships to the USA duty-free under CUSMA.

Bottle batteries These cylindrical packs mount in a holder shaped like a water-bottle cage, so they are light and easy to lift on and off. We carry a 36V 10Ah and a longer 48V 10Ah version, both favourites for folding bikes and lighter assist setups that do not pull much current.

Downtube batteries Our broadest range, made in Reention's Poly DP cases, the standard downtube enclosures used across much of the ebike world, so brackets and spare parts are easy to come by. Every model has a moulded-in mount for a motor controller, so a Grin Baserunner sits right on the battery for a tidy install, which makes these the go-to packs for most of our kits. They bolt onto your frame's water-bottle eyelets, and for a more secure, less wobbly hold our Triple Bob battery rail clamps the cradle to almost any frame. Choose from 36V, 48V, and 52V packs spanning 14.5Ah up to 24Ah, including the long-range 48V 21Ah and 52V 20Ah.

Triangle batteries For bigger capacity, the triangle packs fill the whole front triangle of most diamond-frame bikes. Velcro straps on all three sides hold the pack in place, which does make it a bit fiddly to pull out. All are UL 2271 certified with higher-current BMS boards, so they pair well with powerful 52V and 72V builds: the 52V 21Ah, 52V 31Ah, and 72V 15Ah.

Fuel Tank Our largest single pack, the Fuel Tank holds over 1.5 kWh in a downtube-mounted casing shaped like its namesake. It is a great pick when you want maximum range in one pack, though the extra width can get in the way of pedalling on some frames. We carry 52V 29Ah and 72V 19Ah versions.

Typical range assumes about 10 Wh/km; see How to Choose a Pack below and the Trip Simulator for a number matched to your build. Weights are real pack weights; large packs are billed at a higher shipping weight under Dangerous Goods rules. Our triangle packs and the 48V 21Ah downtube carry UL 2271 certification, and all packs ship UN38.3 certified.

How to Choose a Pack

The first filter is simply what fits your frame, and that alone often decides between a bottle, downtube, or triangle pack. The second is a quick compatibility check: the pack's maximum current has to cover what your controller will draw. Most of our packs run a typical kit with room to spare, so this mainly matters on high power builds. Pair a controller set to 40A with a pack rated for 25A and the BMS will either cut out at full throttle or the pack will run stressed and wear out faster. A battery rated for more current than your controller draws is never a problem.

Next, make sure the pack holds enough energy for your range. Range depends on the battery's watt-hour capacity and how much energy you use per kilometre. At average speeds most riders use about 10 Wh/km, which keeps the math simple: a 400 Wh battery goes about 40 km, and a 720 Wh battery about 72 km.

Ride hard, tow a trailer, or haul a loaded cargo bike and that climbs to 12-15 Wh/km; use the motor sparingly and it drops to 6-8 Wh/km. The table below shows the range of a few example packs under light, average, and heavy use:

	Range with Light Use	Range with Typical Use	Range with Heavy Use
3 Parallel LiGo (~300 Wh)	35-45 km	25-35 km	18-22 km
36V 14Ah Downtube (~500 Wh)	60-80km	45-55km	30-35 km
48V 15.5Ah Downtube (~740 Wh)	90-115km	65-75km	45-50 km
52V 20Ah Downtube (~1050 Wh)	120-150 km	90-110 km	65-75 km

 

It makes little difference whether you run a small geared motor, a large direct drive, or a mid drive. Range comes down to how you ride, not which motor is on the bike.

The Case for Extra Capacity

Say you have a 12 km trip to work and back, so the full 24 km round trip needs about 240 watt-hours. A 36V 8Ah battery at 288 watt-hours should be a perfect choice, no?

Unless you are seriously budget or weight constrained, it would probably be a bad investment. A pack sized to the trip leaves no reserve for errands on the way home or the night you forget to plug it in. Small packs also age faster, because every trip works each cell harder. Once that 8Ah pack fades to 7Ah, your commute is suddenly at its limit and the charger starts riding to work with you.

Most people find that once they have an ebike, they ride it far beyond the commute, and a pack that can do 50+ km on a charge opens up trips a bare-minimum battery never could. Buy a 15Ah pack instead of that 8Ah one and even after it loses 30% of its capacity over years of use, it still covers the 24 km commute with room to spare.

Extra capacity also unlocks partial charging with a Satiator: instead of charging to 100% to squeeze out every km, you set your everyday charge to 80 or 90%. That one habit can multiply both the cycle life and the calendar life of a lithium battery.

Parallel Connecting Batteries

Connecting two or more batteries in parallel is a simple way to add both range and current handling. You can mix old and new lithium packs, or even packs from different manufacturers with different capacities, as long as they are the same voltage. We stock a parallel battery joining cable for exactly this.

Charging is where parallel packs need some care. If you leave them connected while charging, the charge current is shared and both packs stay at the same level, but one of them is being charged through its discharge port. On single port BMS circuits (like our LiGo 10X) that is no concern. On dual port BMS boards, which have separate charging and discharging mosfets, the pack fed through its discharge leads has no overcharge protection, and that is a safety risk if a cell in it misbehaves.

The safer alternative is to charge each battery with its own charger and connect them in parallel only for riding. Just make sure both packs really are fully charged first; you do not want to join a full pack to a flat one.

36V or 48V?

We sell roughly equal numbers of 36V and 48V packs, and all of our conversion kits and controllers work fine with 36V, 48V, or 52V batteries (our Phaserunner controller even runs 72V packs). The voltage simply sets the maximum unloaded speed of the motor. A 48V ebike is not intrinsically better, more powerful, or faster than a 36V ebike, despite what the ill-informed internet will lead you to believe. What matters is the total power in watts going into the motor, not the voltage at which that power is delivered.

It is true that a given motor winding can spin faster at a higher voltage, which is where the perception comes from. A fair apples to apples comparison means changing both the battery voltage AND the motor winding. The slow wind Grin motor (7.5 rpm/V) at 48V is effectively identical to the standard wind motor (10 rpm/V) at 36V.

For most of our hub motor kits, using the recommended winding for the wheel size (fast wind in 20", slower wind for 26"), a 36V battery gives a full throttle commuting speed of 30-35 kph, while a 48V battery gives closer to 40-45 kph. You can choose other voltage and winding combinations to suit your need; explore them in our motor simulator, or put a complete kit together in the kit builder.

If you are replacing an existing battery, a pack with the same nominal voltage is always safe. If you have a generic 36V ebike that is not from us and want to move up to a 48V or 52V pack for more speed, more often than not you can do it without damaging the electronics. Most 36V motor controllers use 60V rated mosfets and 63V rated capacitors, so even a fully charged 52V battery will likely not exceed these values. But it might.

Series Connecting for 72V?

It is possible to series connect two 36V batteries to make a 72V setup, but the only battery we make that is designed for this is the LiGo 10X. With all other batteries, it is essential to put a pass diode across the output of each pack, so that when one BMS circuit trips it is not exposed to a large negative voltage. We stock a series battery cable with this diode built in.

Series connected packs should have identical capacities and specs. You also want your controller or Cycle Analyst low voltage cutoff set so that discharge stops as soon as one pack trips. Otherwise current keeps flowing through the tripped pack's pass diode, and the diode will overheat and fail.

Battery Connectors

We use Anderson Powerpole connectors as the standard discharge plug on all of our battery packs. They are genderless, so the same plug works on both a load and a source, and they withstand the arc of inrush current from capacitive loads far better than bullet style plugs.

For the charging port, most of our current packs and generic chargers use the 3 pin ST connector: it fits the downtube enclosures, charges at 8A with no problem, and has a third pin for battery temperature sensing. It replaced the common but low current DC barrel plug we once used. The other standard you will see is the female 3-pin XLR, the native plug on our Satiator chargers, where quality Neutrik connectors rated for a full 15 amps per pin allow very rapid charging. Satiators are usually sold with adapters, so one charger can service ST3 packs and other plug types too.

Battery Shipping

Large ebike batteries count as Class 9 Dangerous Goods, so shipping them means strict packaging and labeling, UN38.3 test certification, and a trained, certified handler. When you order a large battery from us, an automatic Dangerous Goods handling fee is added and the pack ships separately from the rest of your kit. The exception is our LiGo 10X, whose modules are each under 100 Wh, so it ships alongside your kit with no extra fee.

History

Here at Grin we've been dealing with ebike batteries for nearly 20 years during which we've offered over 100 variants of NiCad, NiMH, LiFePO4, LiPo, and Lithium-Ion packs in all kinds of voltages, geometries, and capacities. For many years batteries were one of the most unreliable and short lived parts of the ebike system, with packs getting worn out after just 2-3 years of use. But the rise of mass produced 18650 and 21700 cylindrical lithium cells for high power consumer goods like power tools has shifted the dynamic. Ebike batteries made with quality cells are cheaper, lighter, and with far longer life spans than we could have ever wished for in the past, and are also incredibly dependable. We're happy to stock frame-mounted packs in sizes to suit almost any conversion, from compact bottle batteries up to 1500 watt-hour triangle and Fuel Tank packs. 

Where to Order