Who the hell am I to tell you what a battery's rating is?
Do I have the qualifications to be doing stuff like this? Some say that I don't.
You be the judge.
Since 1992 I have been designing and building electronic devices for a large number of clients. My first products were camera remote-control systems for sports photographers. As these systems, and other devices, transitioned from wired to wireless the performance of the batteries they used was very important as there was no way to replace them during use. This led to me doing more and more battery testing and developing the electronics to charge, test, and protect them.
As battery technology advanced, from NiCd to NiMH to Li-Ion and now ultracapacitor/Li-Ion hybrids, the devices I built and the battery testing I did advanced along with them. I started specializing in power management electronics; battery chargers, energy harvesters (for charging from heat, light, or vibration/movement), power supplies, battery analyzers, electronic loads for battery discharging, and battery management/protection systems. This is the work I still do today.
My clients have included the US Army, National Geographic, Sports Illustrated, Eastman Kodak Company, and hundreds of other companies from large to small. Part of the work I've done for a lot of my clients has been battery testing. Sometimes they want to recommend a good battery to their customers. Other times they're batteries I have chosen to combine with my electronics to form a complete, protected power source for them to incorporate into their products.
Depending on my client's requirements this testing can take up to several weeks to complete. I use a subset of these tests when evaluating the batteries we use when vaping. This includes continuous-current tests to establish the battery's true (and safe) ratings. They also help to determine if there's any risk of venting if one of our mods autofires or a mechanical mod's button is accidentally pressed. The pulse-current tests measure the degree of voltage sag we would see when vaping at different current levels. Both types of tests are done the same way for every set of batteries I test, over 110 different ones to date (almost 400 batteries total).
This consistency in the testing allows for direct comparison of the performance of different batteries even if the pulse discharging I do doesn't match the way you vape.
Safety is my number one priority. While I often test at discharge current levels that can result in unsafe battery temperatures, this is the only way to figure out what a battery's true and safe ratings are. No battery is totally safe but we can certainly avoid taking unnecessary risks.
This is critical.
There is a huge difference between a battery's rating and a capability of the battery. You might be able to vape with a battery at 40A but that doesn't make 40A the battery's rating. It's just something the battery can do without venting. You still don't how the battery performs compared to others, how much the battery is being damaged, or what the safe limits are.
A rating is different from a capability because it uses a set of important criteria to establish the rating. Things like temperature, voltage when discharging, cycle life (how many times it can be charged/discharged) are defined and limits are set. This allows for direct comparison of the performance of different batteries and is how I test. The tests determine not only the safety limits of the battery but also the performance limits when vaping.
In my blog at ECF I have listed the equipment I use and the steps I follow when testing. This allows anyone to replicate my tests if they want to:
My cell testing equipment and setup | E-Cigarette Forum
What's done for each cell test? | E-Cigarette Forum
Does all this make me some kind of battery expert? Hell no. But I do feel I am qualified to do this testing. My results offer you a resource you can use when choosing a battery that will not only be safe for the way you vape but will also give you great performance.
If there's something you don't like about the testing or the ratings/performance tables, let me know! I'd be happy to read what you have to say and discuss it with you. Over the past few months the feedback I've gotten has resulted in some good changes to the tables to make them less confusing and easier to read.
Each of us has to decide which battery tester's results we will use. Different testers use different criteria when setting a rating or when comparing batteries. Find out how they test, compare their results, and pick the tester you trust the most with the batteries you use.
Thanks for your time!
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