Need help finding 36V 29ah cube...

Replacing SLAs on my kids electric motorcycle. Kuberg Trial-E
https://www.kuberg.com/en/young-rider
3 12 v 12ah SLAs. And would like to replace them with a nice light 36V cube around 25ah if possible.

Wanted to buy the cube from Luna, but does not seem to be in stock ever.
https://lunacycle.com/36v-panasonic-pf-18650-29ah-pack/

Any ideas where I can find a similar high powered cube? Would like to get something up over 1000 Whours that will still fit in his bike so we can go for long rides.

36v Panasonic PF 18650 29ah Pack

I'm not sure, but I think you can contact them and tell them to hurry the *heck up.

You can try contacting EM3EV. They may be able to do a custom build for you.

https://em3ev.com/shop/?prod_cat_=ebike-battery-in-case