(2023-09-04) When marketing beats common sense... again ------------------------------------------------------- Let's take a look at the official Panasonic's 3V lithium battery capacity chart, shall we? CR1616: 55 mAh CR2012: 55 mAh CR2016: 90 mAh CR2025: 165 mAh CR2032: 225 mAh I chose the Panasonic brand for this comparison because that's what Casio installs into their (CR-compatible) watches out of the box. Now, let me clarify the designations. In the CRxxyy type code, xx is the battery diameter in millimeters and yy is its thickness in tenths of a millimeter. So, for instance, CR2016 means 20 mm wide and 1.6 mm thick. You get the idea. First, lets omit CR1616 as I just included it here to showcase there's no need in it when we have CR2012. But some watch modules deliberately make you buy a more rarely occuring battery type that's not interoperable with anything else... just because. That's the first marketing trick I'm going to mention there, but in fact it's much less dirty compared to what I'm about to tell you. Now, let's take three of my favorite Casio watch modules from all classes: 2719 (analogue, which is in fact Miyota 2S60 I've already written about), 2747/5574 (ana-digi, the module is pretty much the same, only the display differs a bit) and 593 (digital, powers F-91W and a lot of other classic digital watches by Casio) as examples. The 2719/2S60 is powered by a CR2012 and promises about 10 years of run time on this battery, which already is good enough, the 2747 promises the same ten years on the CR2025 battery, and the 593 module promises around 7 years on CR2016. Nice. But... can it be even better? So, I dismantled three Casio watches with these modules: MTP-1219A, AW-80 and F-84W respectively. Let me tell you what I saw there. With the 2719 module (MTP-1219A), fitting even CR2025 there is definitely out of question. It's too thick. With CR2016 though, it's a different story: the movement technically has nothing to prevent fitting it in there except the metal fixers tailored for 1.2mm height. But, with a bit of trickery and scotch tape on the metal caseback, it can be done and caseback screws down properly. So, we lost nothing but gained in longevity. How much did we gain? I'll calculate this a bit later. With the 593 module (F-84W), I was able to fit a CR2025 instead of CR2016 although the outer battery frame wasn't closing so nicely (by the way, not every genuine 593 watch even has this frame). Again, a bit of scotch tape on the caseback and we're good to go. With the 2747 module (AW-80), I managed to fit a CR2032 instead of CR2025 in the very same manner. And the movement started working even nicer than before (to be honest, I thought I had damaged that watch beyond repair with some of my previous experiments). So, was it all worth the risks? Let's calculate the relative capacity increase in each case. Upgrading from CR2012 to CR2016 leads to (90/55 - 1) * 100 = 63.6% more battery life (16.3 years instead of 10 years projection for 2719), upgrading from CR2016 to CR2025 leads to (165/90 - 1) * 100 = 83.3% more battery life (12.8 years instead of 7 years for 593), and upgrading from CR2025 to CR2032 leads to (225/165 - 1) * 100 = 36.4% more battery life (13.6 years instead of 10 years for 2747/5574). And the real life figures can be even more stunning but these upgrades are significant even compared to what the manufacturer states. I mean we can confidently say something like 19 to 20 years for 2719 and 15 years for 593 and 2747/5574, provided we install an absolutely fresh battery and (in the latter two cases) don't use the piezo signal and backlight a lot. Let me stress it again: if even I was able to fit CR2016 instead of CR2012, CR2025 instead of CR2016 and CR2032 instead of CR2025 with little to no effort and screw the casebacks properly afterwards, there obviously were absolutely no technical obstacles for the manufacturer to support those longer lasting batteries in these watches out of the box. And the decision not to do this was a purely marketing one. And the fact this decision was made long before the newer trend of returning back to "3-year" SR batteries just proves that this struggle against common sense isn't a new thing at all, and it merely intensified during the last decade. --- Luxferre ---