From an earlier project, I've got an unreasonable amount of a particular type of 9s2p 18650 Li-ion battery packs. The cells are nothing to write home about, but overall, that nets me about 1.9 kWh of capacity if I can assemble those 20 packs into one battery unit (and probably add balancing, which Bosch didn't seem fit to integrate).

Connector Candidates

Some detective work later, here is what probably matches the battery pack connector. The order code seems to be

DJ7 / HD (series / manufacturer part)
03 (number of positions)
19, 2A, 22 (series?)
-
6.3 (blade width in mm, hence Sumitomo "250 type" (mils))
-
1, 2 (male, female type)
0, 1 (unknown option)
[-] (optional part)
[B] (black plastic)
J (unkown option)

	female terminal type	male terminal type
"DJ series"	DJ70319-6.3-21	DJ70319-6.3-11

Haidie #	? (see HD0322-6.3)	HD0319-6.3-11J
Haidie Mfr. #	? (see HD0322-6.3)	926097-1
Terminals	DJ623-E 6,3 B DJ623-E6.3A DJ623-6.3 Sumitomo 1500-0068 ?	DJ612-6,3 B DJ612-6.3 Sumitomo 1500-0083 ?

Purchase options:

"Yueqing Enzhe electric appliance Store" (100 pc qty)

https://de.aliexpress.com/item/1005002674128454.html

"AutoAcessories Store" (contact seller for this type and 20-100 pc qty)

https://de.aliexpress.com/store/5023204

"Haidie Electric" (HD0319-6.3-11J, HD0322-6.3-11J, HD0322-6.3-21J)

https://www.hdconnectorstore.com/

RuiAn Huzhong Auto Electeonic Co.,Ltd. - www.hz-ae.com

"dojioxcn Co., Ltd. Store" (DJ623-E 6,3 A/DJ612-6,3 B)

https://de.aliexpress.com/item/1005003163652350.html

Many Wrong (But Better?) Choices

I'm not a fan of the 3 little barbs with which the housings lock onto each other, as this promises to be yet more wrestling to mate / un-mate. There seem to exist a wide variety of locking features and pin orientations / positions within a shared plug contour. Most likely the Terminals are interchangeable, but even here variants exist.

It's often hard to see in the iso perspective pictures, but those orientation variants can really get you. The locking features are perhaps a better corroborating indictor which one is appropriate when matching this style of connector. Here's DJ7032A (left) vs DJ7031 (right):