Bolt-shaped connections on the battery too short

[boatelectronicsdiy]

I found this Fly Power on amazon. Is this what you have?

View attachment 45057
Notice that it says M8 for the terminals. M8 comes in both 1mm and 1.5mm pitch. I am guessing the M8 studs you purchased are the wrong pitch.

I would take one of the bolts to a hardware store and check it with their thread sizing tools. (Or better yet, go buy one)

https://www.amazon.com/Lug-Wheel-Stud-Thread-Checker/dp/B009UZ7S60/

I have one similar to this and find I use it all the time.

Yes, that's what I have and I have finally found the right screws/posts - see attached. It turns out, not all that says M8 on amazon is actually M8 in size.

Here is the product that fits: https://www.amazon.com/gp/product/B08Y8D2DSG/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

These batteries are excellent - very lightweight, well made, you get a charger with each and they have a built-in USB port, BMS and a voltage display. Plus they are waterproof - ideal for my application on a sailboat.

 

[FilterGuy]

Yes, that's what I have and I have finally found the right screws/posts - see attached. It turns out, not all that says M8 on amazon is actually M8 in size.

Here is the product that fits: https://www.amazon.com/gp/product/B08Y8D2DSG/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

These batteries are excellent - very lightweight, well made, you get a charger with each and they have a built-in USB port, BMS and a voltage display. Plus they are waterproof - ideal for my application on a sailboat.

I would be concerned about using those.

I have not used Flypower and I can not find a picture of the terminal without a post in them. However, on most battery terminals of that nature, the primary connection is through the pad on the terminal, not the threaded bolt. The picture on Amazon of the studs showes two aspects that would make me believe the connection between the stud extender and the pad my be considerably compromised.



The gap and the bumps will both minimize the contact area to the battery terminal pad.

For lower current applications this will not be a problem, but when under a high current load, this could be significant.