Lenovo ThinkBook 15 G3 ACL

Type 21A4 Laptop, from 2021 52 hardware reports
Memory
Up to 40 GB
1 laptop-size slot + soldered
SSD
2+ M.2
At least 2 M.2 SSD slots
SSD length and charger
Coming next
Checked from separate sources
Partly soldered

Yes, you can add one stick. Up to 40 GB seen working.

4 or 8 GB is soldered to the board and one slot is free for a DDR4-3200 laptop-size stick.

Free slots
1 SO-DIMM slot
Type
DDR4-3200 260-pin SO-DIMM
Soldered
4 GB or 8 GB, depending on the configuration
Most seen working
40 GB in two or more machines
Firmware says
64 GB maximum (often wrong, so we show what machines run)
SSD slots
At least 2 M.2 SSD slots listed by the firmware
How sure
43 of 52 reports show this layout
See 32 GB DDR4-3200 SO-DIMM on AmazonOpens an Amazon search for this exact spec.

Worked out from 52 hardware reports of this laptop. Sources and method. Updated 9 Nov 2026.

1 laptop-size slot plus soldered memory
Illustration

Questions

Can I upgrade the RAM in the Lenovo ThinkBook 15 G3 ACL?

Yes, you can add one stick. Up to 40 GB seen working. 4 or 8 GB is soldered to the board and one slot is free for a DDR4-3200 laptop-size stick.

What type of RAM does the Lenovo ThinkBook 15 G3 ACL use?

DDR4-3200 laptop-size sticks (SO-DIMM, 260-pin).

How much RAM can the Lenovo ThinkBook 15 G3 ACL take?

Machines in the reports run up to 40 GB. The firmware reports a maximum of 64 GB, a figure that is often wrong.

Does the Lenovo ThinkBook 15 G3 ACL have an M.2 SSD slot?

Yes. The firmware lists at least 2 M.2 SSD slots, in 52 reports. Some firmware leaves a slot out, so there may be more.

Is this my laptop?

Check the label on the bottom. It should say ThinkBook 15 G3 ACL, and the type code starts with 21A4.

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