Ive been using the Wolf Whoop batteries on Amazon. The same price as the GNB batteries but you get one more battery and they fit the cockroach frame better in my experience.

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https://www.amazon.com/Wolfwhoop-260mAh-Battery-JST-PH-Connector/dp/B07CCMPRCD/ref=sr_1_18?ie=UTF8&qid=1540842949&sr=8-18&keywords=wolfwhoop