Given the fact this vehicle needs a reliable replacement 12V battery I "by accident" found a special one @ a good price.
It seems to be the right one given the fact it is a LIFEPO4 one, but who knows? Lithium battery LiFePO4 BS Battery BSLi-02 12V-140A, 2Ah by BS Battery.
Here's the link to its price, pic and specifications:
Lithium battery LiFePO4 BS Battery: designed for the most demanding riders, looking for higher and safer performance, faster acceleration, highly reduced weight and much longer battery life. BS Battery is proud to announce the launching of its brand new and innovative lithium-ion motorcycle and...