Battery Building ToolsCell Database P45B

✱ Render

21.55 × 70.15 mm · 70 g

21700NMC Mooch-tested · 45 A

Molicel P45B

Name: Molicel P45B Lithium Battery Cell
Brand: Molicel

Molicel · released 2022

Capacity4500 mAh16.2 Wh · 231.43 Wh/kg

Mooch continuous45 ASize to this figure

Resistance7 mΩDC internal resistance

Voltage window3.6 V2.5 – 4.2 V

Standard charge4500 mA~1 h to full

Build a pack with this cell →Download spec sheet (PDF)Open the datasheet Mooch's test ↗

At 4500 mAh, this ranks #40 of 72 21700 cells in our database. Mid-range for capacity among 21700 cells. Higher discharge than 82% of 21700 cells in our database. Great for high-drain builds.

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Full specifications

Electrical
Chemistry	NMC
Nominal voltage	3.6 V
Max charge voltage	4.2 V
Discharge cutoff	2.5 V
Max continuous discharge	45A (Mooch-tested)
Mooch CDR (trusted)	45 A
Standard charge current	4500 mA
Standard discharge current	900mA
Internal resistance	7 mΩ
Physical
Form factor	21700
Dimensions	21.55mm × 70.15mm
Weight	70 g
Top type	Flat Top
Protected	No
Wrap color	Gray
Performance
Capacity	4500 mAh
Energy	16.2 Wh
Specific energy	231.43 Wh/kg
Energy density	633.14 Wh/L
Power density (gravimetric)	2,314 W/kg
Power density (volumetric)	6,331 W/L
Cycle life	500 cycles
Year released	2022
Operating Limits
Charge temp	0°C to 60°C
Discharge temp	-40°C to 60°C

Independent test data: Mooch's test of the P45B ↗

At the standard 4500 mA charge rate, a full charge takes about 1 hours. The last bit is a slow taper to top it off.

Voltage operating window

Cutoff
2.5VNominal
3.6VMax charge
4.2V

Usable range: 1.7V

C-rate conversion: Molicel P45B (4500mAh)

C-Rate	Current (A)	Theoretical runtime
0.2C	0.9 A	5h 00m
0.5C	2.25 A	2h 00m
1C	4.5 A	1h 00m
2C	9 A	30m
3C	13.5 A	20m
5C	22.5 A	12m
8C	36 A	7m 30s
10C	45 A	6m

Highlighted row is closest to the rated 45A continuous discharge.

Charging

Rate	Current	Estimated time
0.5C	2,250 mA	~2h 00m
1C	4,500 mA	~1h 00m

These are estimates for the constant-current phase. Real charge time is a bit longer because of the slow taper at the end.

Datasheet

Download official Molicel P45B datasheet (PDF) ↗

Pack scaling

Series voltage configurations

Config	Nominal V	Max V	Min V	Common use
1S	3.6V	4.2V	2.5V	Flashlights, single-cell devices
2S	7.2V	8.4V	5V	RC vehicles, 7.2V packs
3S	10.8V	12.6V	7.5V	Power tools (10.8V nominal)
4S	14.4V	16.8V	10V	Ebike (small), some power tools
7S	25.2V	29.4V	17.5V	Ebike (24V system)
10S	36V	42V	25V	Ebike (36V system)
13S	46.8V	54.6V	32.5V	Ebike (48V standard)
14S	50.4V	58.8V	35V	Ebike (52V high-power)
16S	57.6V	67.2V	40V	DIY powerwall

Parallel capacity scaling

Config	Capacity	Energy	Max discharge
1P	4,500 mAh	16.2 Wh	45 A
2P	9,000 mAh	32.4 Wh	90 A
3P	13,500 mAh	48.6 Wh	135 A
4P	18,000 mAh	64.8 Wh	180 A
5P	22,500 mAh	81 Wh	225 A
6P	27,000 mAh	97.2 Wh	270 A

Example pack configurations

7S2P

24V ebike / small pack

14 cells25.2V nominal9,000mAh227Wh90A maxCell weight: 0.98 kg (add ~15% for wiring and BMS)

13S4P

48V ebike standard

52 cells46.8V nominal18,000mAh842Wh180A maxCell weight: 3.64 kg (add ~15% for wiring and BMS)

16S4P

DIY powerwall

64 cells57.6V nominal18,000mAh1037Wh180A maxCell weight: 4.48 kg (add ~15% for wiring and BMS)

4S6P

Power tool replacement

24 cells14.4V nominal27,000mAh389Wh270A maxCell weight: 1.68 kg (add ~15% for wiring and BMS)

Design a custom pack with this cell:

Pack Planner →Pack Designer →

Application suitability

PowerwallsHigh capacity means more stored energy per cell. Fewer cells needed for a given kWh target.

Ebike PacksGood balance of capacity for range and discharge for hills. Works well in most ebike packs.

Car AudioEnough discharge to handle amplifier bursts without voltage sag.

High-Drain VapingAbove the 25A Mooch CDR threshold. Suitable for regulated and mechanical mods.

FlashlightsHigh capacity means long runtime. Great for everyday carry and extended use.

Power ToolsSufficient discharge and capacity for most power tool packs.

Physical dimensions

Dimensions21.55mm × 70.15mm

TopFlat Top

Format21700

Similar cells

Same format and chemistry, within ±500mAh capacity:

Cell	mAh	CDR	Wh	Weight	Wh/kg
Molicel P45B (this cell)	4500	45A	16.2	70g	231.43
Ampace JP50P1	5000	40A	18	72g	250
Amprius INR21700-50Q	5000	50A	18	70g	257
BAK N21700CG	5000	50A	18	70g	257
Efest 21700 5000mAh 10A	5000	10A	18	69g	261
Epoch 21700 5000mAh	5000	10A	18	69g	261

Build with this cell

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Frequently asked questions

What is the capacity of the Molicel P45B?

What is the maximum discharge rate of the Molicel P45B?

How many P45B cells do I need for a 48V ebike battery?

What does the Molicel P45B weigh?

Can I use the P45B for vaping?

What is the cycle life of the Molicel P45B?

What temperature range can the P45B operate in?

What size is the Molicel P45B?

Handling and safety

Lithium cells can be dangerous if mishandled. A few things to keep in mind:

Never charge above 4.2V or discharge below 2.5V.
Store cells at around 3.6-3.8V (roughly 40-60% charge) for long-term storage.
Don't mix cells with different capacities, chemistries, or states of charge in a pack.
Inspect wraps before use. A torn wrap can cause a short circuit.
Always use a BMS or balance charger appropriate for your pack configuration.
Keep cells away from metal objects, keys, and coins. A short across the terminals can cause fire.

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Specs come from manufacturer datasheets and independent testing; Mooch-tested discharge ratings are shown when available because they reflect real continuous performance better than headline datasheet numbers. Browse the full 18650 & 21700 cell database to compare every cell.

Disclaimer: We do our best to keep the information on this page accurate, but we cannot guarantee that all specifications are correct or up to date. Cell characteristics can vary between production batches and may change over time. Do not rely solely on this data for safety-critical applications. Always verify against the manufacturer's official datasheet before use.