bionx 1954
100 W

I bought some Bat619G which are 18v@3A for 70.00cdn each. I opened them up and it seems to have Konions inside 5S2P. There is two cables from the circuit board 1 for a thermal sensor and the other goes to the fuel cell lights on the casing. So like other FP there is no BMS
So by placing 2 packs of 619G in series you get 36V@3A, or using 620 you get 36V@4A
On Ebay Bosch Bat620 are selling in 2 packs for 150.00. Amazon.ca is offering 2 Bosch 620 for 150 CDN with free shipping. Also Home Depot ( US ) twin pkg for 149.00 US
I have been using Bosch Fat Pack Bat 836 (36V @2A) for 4 years now and paid around 100.00 US for each pack about 3 years ago.
By using 2 18v Bosch Bat620@4A each. You get 36 volt @4A for 150.00.
The Bat 620 & 619G are real easy to assembly a pack because they are 2 rows of 5 cells stacked on top of each other These new "cool packs" have a new type of casing that are design to remove cell heat from battery casing.