Try a supercap instead of a battery and measure the end voltage. The end voltage should be roundabout the same with the supercap and rechargeable batteries. It shouldn't exceed the maximum end voltage of the battery to be used, and high enough to store enough energy. Given the charging/discharging curve of NiZn Anything between 1,6V and 1.85V will more or less fully charge the battery without harming it. If under 1,4V it is empty and the voltage will dramatically fast so the low batt alarm really might not work as one might expect it.
Tomasz Lewicki schrieb am Donnerstag, 5. Februar 2026 um 09:08:42 UTC+1: > I ordered NiZn rechargeable batteries. I don't think I need to worry about > damaging the station due to overvoltage, because - as I checked on the only > AA lithium battery I have on hand, which has been sitting around for two > years - the voltage on it is exactly 1.79 V. So 1.6 V, even when fully > charged, is unlikely to be a problem. I'm more concerned about charging. > > wtorek, 3 lutego 2026 o 09:20:11 UTC+1 [email protected] napisał(a): > >> Afaik you could simply use NiZn, which won't fully charge in this >> station. Also, the low battery warning will most likely not fit when this >> cell is being used. I'd give it a try. Also, you might not want to put >> fully charged NiZn cells into your device. >> >> But absolutely no guarantee you won't ruin the station. >> >> Tomasz Lewicki schrieb am Dienstag, 3. Februar 2026 um 07:13:53 UTC+1: >> >>> I would like to ask if anyone still uses the HP-1001/1002 (WS-1001/1002) >>> station with the WH24 external sensor. I am having trouble finding the >>> right batteries for this sensor. I know it is old equipment, but maybe >>> someone will be able to help me. >>> >>> I got the station from a friend who bought it in 2015 and didn't use it >>> because he couldn't install it (he lives in a multi-story apartment >>> building). I got it in 2023 and started using it in the spring of 2024. I >>> found the original manual here -> https://fccid.io/WA5WH24B (April 2013 >>> version). The Polish distributor's manual is from January 2014. It contains >>> an important note that is not included in the original manual about >>> powering the WH24 with 1.5 V ZnMn rechargeable batteries: "The outdoor >>> sensor can only be used with the special ZnMn rechargeable batteries with a >>> rated voltage of 1.5 V included in the set." Since I didn't have any, I >>> used regular 1.2 V NiMH rechargeable batteries, but they quickly died >>> during the cold spell, which is not surprising. That's why I used 1.5 V >>> lithium batteries. They worked for almost two years, give or take a few >>> weeks. But now I have to replace them, which brings me to my question for >>> WH24 users - what kind of batteries should I use? There are no longer any >>> 1.5 V ZnMn rechargeable batteries on the market, but there are NiZn >>> batteries with a voltage of 1.6 V. Will these be suitable? Should I go for >>> lithium batteries again? The thing is, access to the external sensor is >>> very difficult and I can't easily replace it if something goes wrong. >>> >> -- You received this message because you are subscribed to the Google Groups "weewx-user" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/d/msgid/weewx-user/9975ad10-3b19-403b-af43-205b74e97906n%40googlegroups.com.
