(ISO) Beginners guide to rechargeable batteries

Munkel

Newly Enlightened
Joined
Oct 25, 2019
Messages
21
<noob alert>

I am getting more serious about lego'ing old SF flashlights (predominantly just 1 cell lights with LED heads) and starting to have issues selecting batteries. I have done a lot of searching, though probably using the wrong terms as I am still stuck. If there are any good posts on this I would love to find them. My questions revolve around the following:
  • Button top vs flat top, it looks like some of my SF heads would not work well with a flat top but my LF heads would work fine. Spring vs no spring in the head. Many times that tends to put my max length too high for the body. if I use button tops it seems.
  • Max continuous discharge, is bigger always better?
  • Capacity in mAh, I assume bigger is better but often it seems the higher the mAh the lower the max cont. discharge in many instances.
  • Which is better, having a high mAh or a high max cont. discharge? Or is it really as simple as higher mAh will last longer but be dimmer and higher max discharge will be brighter and go quicker?
I have been trying to stick with Vapcell and a few other popular names for quality purposes.

Currently searching for the following types for builds, 16340, 18350, 18500.

I know I am leaving out protected vs. unprotected as well as a few other factors like length and diameter bit I feel like I have a grasp on those topics.

Example, current search for 18500 Vapcell batteries and I have 5 options:
2000 mAh 5A
2200 mAh 4A
1200 mAh 10A
1500 mAh 15/25A
2400 mAh 5A

Thank you in advance for any advice and knowledge!
 

jon_slider

Flashlight Enthusiast
Joined
Mar 31, 2015
Messages
4,474
Flashlight Wiki

LiIon Safety 101

> Which is better, having a high mAh or a high max cont. discharge?

I choose max mAh over max discharge, because, I dont use Max output. My interest in battery life and sustainable output, takes priority over brief moments of maximum output that is not sustainable.

> I have been trying to stick with Vapcell and a few other popular names for quality purposes.

that seems fine.. and they offer both flat top and button top options.. It is also important to check the length dimensions compared to the "stock" battery offering.

it is Very important to use Protected Batteries in lights that do not have built in Low Voltage Protection (LVP)..

So, I encourage you to focus your questions on Specific lights.. there is no general one size fits all.. You need to know whether the host has built in LVP or requires Protected cells.

as a rule of thumb, flat top cells are almost always UNprotected and should only be used in lights that have built in LVP

otoh batteries with built in LVP are almost always button tops, and should be used in lights that do not have built in LVP
(although not all button tops are protected)
 
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