18650 pack mounting - Page 1
Forum section: electronics / projects

author: tszaboo
author_rank: Super Contributor
timestamp: September 20, 2021, 09:01:45 am
content: I'm looking for some PCB hardware. I have a single cell 18650 battery Pack. It is with wires, NTC, protection circuit, wrapped.I would need to mount this to a PCB. So far our method was having two holes in the PCB and running a zip tie through it.Do you know a more secure, reliable way to mount a battery pack to a PCB? Preferable something that is resealable, so it doesn't require sidecutters in case we want to replace the pack.While one of the obvious choice would be using a battery holder and place the protection circuit on the PCB, I don't want to make this change to the electronics.

author: Whales
author_rank: Super Contributor
timestamp: September 20, 2021, 09:27:55 am
content: To be honest: a couple of cable ties sound rather elegant. High temperature resistance (nylon), very secure (if you use two) but not the best long term vibration resistance (may cut through the pack insulation). They're annoying as hell to replace if you can't access the other side of the PCB, but you could install some large busbar/current-shunt like mounting points on the topside of the PCB to fix this.EDIT: looks like dedicated cable tie mounts are a thing:https://www.mechanicallugs.com/oem-box-collar-lugs/b12-nm-smt-wire-tie-mount-shunt-and-pcb-support-block.htmlhttps://www.digikey.com.au/en/products/detail/advanced-cable-ties-inc/AL-SM1-0-C/10380656Sadly 3d printed brackets probably won't suit unless your application is permanently low temp, low vibration and low manufacture quantity.

author: ajb
author_rank: Super Contributor
timestamp: September 20, 2021, 03:41:49 pm
content: Keystone would be the first place I'd look for something like this. From your question presumably the pack has a flying lead, but depending on how the lead exits the pack you still might be able to use a pair of these PC mount clips that are designed to serve as electrical contacts if you space them out a bit farther:https://www.keyelco.com/category.cfm/Cylindrical-Cell-Clips-THM-and-SMT/For-17-19mm-Dia-Lithium-Ion-Batteries/p/404/id/943/c_id/1207Alternatively, if possible, use a pack that doesn't have a flying lead and then just use the clips above exactly as intended? I guess protected single cell packs in the conventional cell format aren't as common because the protection circuit makes them a bit longer than normal unprotected cells and they don't always fit in holders, but I have seen them, and with separate contacts like the above you can space them as needed to accommodate the extra length.They also have mechanical mounting clips for various types of batteries. They're designed for screw mounting but the steel ones are nickel plated so you could maybe solder them on if you wanted (I don'tthinkyou'd mess with the spring temper at normal reflow temperatures). You'd likely need some sort of end-stop so the pack can't slide out if the grip on the clips isn't tight enough.https://www.keyelco.com/category.cfm/Cylindrical-Cell-Clips-THM-and-SMT/Battery-Clips/p/404/id/943/c_id/950There are also cable clamps in both nylon and metal that might work and provide a more secure grip:https://www.keyelco.com/category.cfm/Multi-Purpose-Hardware/Cable-clamps-Nylon-Steel/p/1260/id/434There are certainly other manufacturers of this sort of hardware that may have better options along these lines.