Molicel P50B 5000mAh 21700 Cell – Up to ~50A for E-Bikes & Scooters

The Molicel P50B (INR21700-P50B) is an unprotected lithium-ion cell (lithium-ion cell) in the 21700 format. It is built for battery packs used in electric bikes, electric scooters and light electric vehicles. Typical capacity is 5000 mAh, nominal voltage is 3.6 V, and continuous discharge current reaches up to ~50 A.

Chemistry is Li-ion INR, the contacts are flat, and the cell measures 21.00 mm in diameter by 70.00 mm in height. This cell was engineered for high continuous discharge applications. Therefore builders choose it where both capacity and power must fit inside one can. Pulse discharge current is higher than the continuous rating, which leaves headroom for acceleration.

The P50B carries no PCB protection board. For that reason it must only be used together with a BMS (battery management system). Actual current limits depend on the BMS, on cooling and on the whole pack design. It is sold as a single component for pack assembly, so it suits pack manufacturers and technically skilled builders.

Key Benefits

• 5000 mAh typical capacity – more stored energy inside one 21700 can, so the finished pack covers a longer range.
• Up to ~50 A continuous discharge – the cell sustains strong pull instead of offering capacity alone.
• Higher pulse discharge current – reserve power for acceleration and steep climbs.
• Li-ion INR chemistry – a balanced mix of energy density, safety and cycle longevity.
• 21700 format – greater energy density than 18650 solutions, so a pack holds more energy at a similar volume.
• 3.6 V nominal voltage – the standard figure used when calculating series-string voltage in packs.
• Flat contacts – suited to spot welding with nickel or copper strip.
• Wide voltage window – from a 2.50 V discharge cut-off up to 4.20 V maximum charge voltage.

Who Is This Cell For?

The Molicel P50B is intended for battery packs in electric bikes (e-bikes), electric scooters (e-scooters) and light electric vehicles. Above all, it is chosen where a build needs both 5000 mAh capacity and high continuous current. That combination is common in performance-oriented drivetrains.

This cell is aimed at battery pack manufacturers and at technically prepared builders. In addition, it is a frequent pick for anyone upgrading an existing pack to a higher-capacity 21700 solution. Because the 21700 can holds more energy, fewer cells and fewer joints are needed for the same target capacity.

Keep in mind that this is not a finished battery pack, and it is not a protected cell. Consequently, it is not suitable for devices that require a cell with an integrated protection board. In such devices the missing PCB has no substitute.

Technical Specifications

Usage Notes

• BMS required – protection against overvoltage, undervoltage, overcurrent and short circuit is mandatory.
• Spot welding – join cells with nickel or copper strip.
• Avoid soldering heat – soldering directly onto the can damages the cell structure.
• Charging – use only Li-ion chargers that match this cell’s specification.
• Damaged cells – never use deformed or damaged cells.

Why Choose the Molicel P50B?

The P50B pairs 5000 mAh of capacity with up to ~50 A of continuous current. Many high-capacity cells simply cannot deliver that current. As a result, this cell fits packs where pull and range matter equally, rather than one at the expense of the other.

The 21700 format also brings higher energy density than 18650 builds. Therefore the same target pack needs fewer cells and fewer welded connections. That means a simpler harness and fewer points of failure inside the pack.

Furthermore, the Li-ion INR chemistry holds up its cycle longevity under heavy load. Flat contacts and 21.00 × 70.00 mm dimensions keep the cell easy to arrange in standard 21700 holders. The 2.50 V to 4.20 V window gives a clear framework for BMS configuration.

Frequently Asked Questions

Is the Molicel P50B a protected cell with a PCB?

• No, it is an unprotected cell without a protection board.
• It is designed for packs where the BMS handles protection.

Is the P50B suitable for e-bike and e-scooter battery packs?

• Yes, it is built for e-bike, e-scooter and light electric vehicle packs.
• Up to ~50 A continuous discharge supports demanding drivetrains.

What is the capacity and voltage of the INR21700-P50B?

• Typical capacity is 5000 mAh.
• Nominal voltage is 3.6 V, with a 4.20 V maximum charge voltage.

How should I connect these cells in a pack?

• Use spot welding with nickel or copper strip.
• Do not solder directly onto the cell, as heat damages its structure.

Can I use the P50B without a BMS?

• No, a BMS is required for voltage, current and short-circuit protection.
• Real current limits also depend on cooling and total pack design.

Why pick 21700 over 18650 for an e-bike pack?

• The 21700 format offers higher energy density than 18650 solutions.
• Fewer cells and fewer connections are needed for the same capacity.

What are the exact dimensions of this cell?

• Diameter is 21.00 mm and height is 70.00 mm.
• Contacts are flat, with no button top.

What discharge cut-off should I set?

• The specified discharge cut-off voltage is 2.50 V.
• Charging must stop at 4.20 V maximum.

The Molicel P50B is supplied as a single 21700 cell for pack assembly. Pair it with a suitable BMS, nickel or copper strip and a Li-ion charger matched to its 4.20 V charge limit. Then you have a 5000 mAh, ~50 A building block for e-bike, e-scooter and light EV packs.