Seiko 7A38 - by the numbers

I have read several post from watch collectors complaining about Renata. I keep a pretty complete battery inventory as every relative I have knows I work on watches so I get all sorts of makes and brands. I have few Renata which I have not had trouble with myself, but my personal preferred battery is the Engergizer silver oxide battery. I can typically log into Amazon and eBay at the same time, enter the battery size and quicly find the best deal. Which since I own 40 7T32 models I buy the 370/371 in a ten pack and the same for the 395/399. Other less popular sizes I look for 5 packs. The 7T32 movement is known for eating batteries like no other. Expected life span per the manual is 12 months! I am constantly changing out 7T32 batteries.

Rough handing of the battery can be a cause also. The Seiko manual specifies NOT to use any metalic object but to use plastic tweezers. The 7T32 has a little trick. There is a extra battery plate separate from the main upper plate. it is held on by two screws. Backing them off about two turns and the battery just drops right in. Leave them tight and it is a lot of pushing and shoving on the battery.

Michael.

Originally posted by myself on August 1, 2014 at 1:00 PM:

From August, Cousins UK have announced that they will be stocking Seizaiken batteries, made by Seiko Instruments:

http://www.cousinsuk.com/catalog/batteries/seizaiken-watch-batteries/seizaiken-3xx

More data here: http://www.sii.co.jp/en/me/datasheets/silver-oxide/seizaiken/  .... Guess what I'll be ordering next time ? 

Well it took a while to finish off my existing stock of Renata #394's but that's what I just did - yesterday:

Note the Seizaiken boxes come with a hologram sticker and a reassuring 'Best Before' date stamp. 

I have been searching for the Seizaiken batteries on ebay Germany, but hadn't found any - as of yet. Nice to know Cousins has them.

Speaking of dodgy Renata batteries, i just received 4 from an ebay seller ,expiry 2020, two of my Yemas just failed inside of a week, tested in another watch and that failed to. Grrrrrr! I stopped using Sony as I saw too many were spewing their guts and destroying watches. May just stick to getting local and buying Energizers,ah blasphemy!

I've criticized Rayovac batteries before (at the beginning of this thread). I bought a 7A38-7120 last weekend. It arrived yesterday, working, but doing the two-second two-step (low battery indicator). I decided to fit a new battery this morning, rather than let it expire. Just as well. The Rayovac #394 fitted had already started to spill its guts - while the watch was still running. There were plenty of little white flakes in the battery well that needed cleaning out - and more weeping out of the battery. Unfortunately I fumbled the battery and dropped it, as I tried to turn it over, so most of them fell off. But you get the picture ....

Interesting about those Rayovacs. I quit using them after I had several alkaline D cells leak in my Maglites. It happened several times so would have been different lots. They had plenty of time left per date stamps and were lightly used. Poor design.