Topic: Question to Ambient 2902 Users in Northern latitudes.

[OldAlaskaGuy]

I have an Ambient WS2902 array. It was first placed into use in September of 2024 and I installed rechargeable EBL 2800 mAh Nickel Metal Hydride low self discharge batteries as backup batteries. No issues during the Winter even with short day light and snow covering the solar panel. Today, after 9 months I received a low battery warning with less than 80% left. Is this the normal expected battery life? This is the first array that I have used that uses a super cap and the batteries only are for backup and not recharged in the array. I have 2 charged and ready to swap out. I use these batteries because they purportedly work well in extreme cold temperatures and have a high reserve capacity. In Spring temperatures usually hover in the 30's and we occasionally get into the minus 20-30F where I live in Alaska. Should I use Lithium Ion batteries instead. EBL makes 3700 mAh lithium rechargeable batteries as well. I realize that 9 months is really not bad at all.

[Vasco]

Yes, use lithium batteries - but not rechargeables.

[Gyvate]

with sufficient solar exposure, the battery life of a WH65 /WS-2902-ARRAY shouldn't be much of a concern as the inbuilt super-capacitor should collect enough energy during the day to run the array during the night or strongly overcast periods. If the exposure is not sufficient, battery energy will be used - and for longer time periods below -10° C / 17° F the use of Li batteries is recommended over Alkaline batteries.

NiMH or Ni-Cd based AA type rechargeables won't have more than 1.2 V and that would soon be too little. Therefore the use of such rechargeables is not recommended.
Li based rechargeables provide longterm constant 1.5 V voltage based on 3.6/3.7 V cells or LI-FeS₂ at 1.5 V.

[SamiS]

My Ecowitt WS69 array has been running on standard Varta Alkalines since June 2022 without any issues or low battery warnings. It is way better than I expected, since our winter is dark, cold and snowy here in Finland at 61 degrees Northern latitude. Monthly mean temp is usually below freezing from November to April, lowest being under -30°C. Based on this experience I think using lithiums or rechargeables at all is not justified.

[OldAlaskaGuy]

I am at 60.6 North so we have about the same seasonal temperatures and day/night hours. About 5 1/2 hours of daylight mid December here and temperatures creep and hold at -20°C to -35°C for a few days at a time. I think that using rechargeables is the the issue because the lower voltage (1.2V). Going back to non rechargeable (1.5V) per Gyvate's suggestion. When I had WS1400/WH24 mounted it was not an issue because the batteries were recharged in the ARRAY. New technology learning curve. Thanks for everyone's input. While looking at my snow covered ARRAY in mid Winter and sipping coffee in my jammers, temps in the minus teens, maybe I should go out and remove the snow, or maybe not.

[Wooks61]

I replaced the original battery with Energizer Ultimate Lithium (non-rechargeable).
Ìt's been in there for at least three winters so-far.

[Vasco]

My Ecowitt WS69 array has been running on standard Varta Alkalines since June 2022 without any issues or low battery warnings.

I have to say I find that very surprising. Lithium batteries are recommended for temps below freezing.

[SamiS]

My Ecowitt WS69 array has been running on standard Varta Alkalines since June 2022 without any issues or low battery warnings.

I have to say I find that very surprising. Lithium batteries are recommended for temps below freezing.

People tend to recommend new techologies even when the old one still serves its purpose just fine. Before Ecowitt I had FineOffset WH1080 also running with alkalines since 2010. It did not have a solar panel, but the batteries still lasted generally over 2 years in the outdoor unit. My all time lowest record is -36.1°C, recorded on that station with alkalines.

[OldAlaskaGuy]

Strange things. per discussions in this thread, I removed the EBL rechargeable batteries (specs in the OP) for the lithium non rechargeables and set the battery alarm for less than 25 for the outdoor ARRAY. Overnight is sends a low battery warning. The EBL batteries were not. I then check the battery level with the GW3000B and GW1200B sensor ID page and they show full and no alarms are triggered ( they are set the same as Ambient)Using a Ambient WS2902 without a console.

[Gyvate]

My Ecowitt WS69 array has been running on standard Varta Alkalines since June 2022 without any issues or low battery warnings.

I have to say I find that very surprising. Lithium batteries are recommended for temps below freezing.

let's say for longer periods below -10° C/ 12° F

[OldAlaskaGuy]

Strange things. per discussions in this thread, I removed the EBL rechargeable batteries (specs in the OP) for the lithium non rechargeables and set the battery alarm for less than 25 for the outdoor ARRAY. Overnight is sends a low battery warning. The EBL batteries were not. I then check the battery level with the GW3000B and GW1200B sensor ID page and they show full and no alarms are triggered ( they are set the same as Ambient)Using a Ambient WS2902 without a console.

Conjecture, probably set off when I was replacing the batteries, possibly polling battery voltage at the same time. Today no battery issues, no lost data.