Lenovo ThinkPad P51
Yes. 4 slots, up to 64 GB seen working.
It takes DDR4-2400 laptop-size sticks (SO-DIMM).
- Slots
- 4 SO-DIMM slots
- Type
- DDR4-2400 260-pin SO-DIMM
- Most seen working
- 64 GB in two or more machines; one machine runs 80 GB
- Firmware says
- 64 GB maximum
- How sure
- 22 of 22 reports show this layout
Worked out from 22 hardware reports of this laptop. Sources and method. Updated 9 Nov 2026.
Batteries in these laptops report 90 Wh.
That is the design capacity the batteries themselves report, and the label can read 1 to 3 Wh higher. Other pack sizes may have shipped, so check the capacity printed on yours before you order.
From 21 battery readings. Sources and method. Updated 9 Nov 2026.
IllustrationQuestions
Can I upgrade the RAM in the Lenovo ThinkPad P51?
Yes. 4 slots, up to 64 GB seen working. It takes DDR4-2400 laptop-size sticks (SO-DIMM).
What type of RAM does the Lenovo ThinkPad P51 use?
DDR4-2400 laptop-size sticks (SO-DIMM, 260-pin).
How much RAM can the Lenovo ThinkPad P51 take?
Machines in the reports run up to 64 GB, and one runs 80 GB. That matches the 64 GB maximum the firmware reports.
What battery does the Lenovo ThinkPad P51 use?
Batteries in these laptops report 90 Wh, going by 21 reports. Other pack sizes may have shipped, so check the capacity printed on yours.
Is this my laptop?
Check the label on the bottom. It should say ThinkPad P51, and the type code starts with 20HH. Other type codes share this name: 20HJ.