Eneloops in outside weather station+ Michigan winter= eneloop doom?

[zband]

I have Eneloops in a external weather station, which is going tp be exposed to MI winter (think nighttime temp sometimes -10F)

Is this going to destroy my eneloops? Should I switch to alkalines for the winter?

 

[Black Rose]

You'll need to switch to Energizer e2 Lithiums for the winter.

The cold will take it's toll on the Eneloops and the alkalines will not stand up to the cold at all.

 

[Daniel_sk]

Alkalines won't work (or will have very low capacity) at such a low temperature. Eneloops might have problems too.
The best option would be to buy lithium batteries, these will work without any problems in freezing temperatures and offer the highest capacity.

 

[zband]

So no rechargeable option?

 

[Mr Happy]

In Sanyo's Eneloop data sheet they list the lowest recommended temperature for discharge as 0°C (32°F), and the lowest temperature for storage as -20°C (-4°F).

I believe the problem with discharge at low temperatures is that the catalytic recombination of hydrogen and oxygen does not work fast enough and the cell may vent. At very low discharge rates this may not be a problem, but your lowest night time temperature might in any case be lower than the minimum storage temperature.

 

[LED_Thrift]

How many cells does the station need? If it just happens to need three cells, which would be 3.6v from three Eneloops, you could use a rechargable lithium [Li-ion 3.7v] without too much trouble.
If it uses two cells, 2.4v from Eneloops, you could probably use a 3.0v lithium rechargable [available from BatteryJunction and probably AW - be sure to use the charger made for the 3.0v cells].
One problem may be that you have to change out the batteries more frequently, as the rechargeables only have about 600 - 700 mAh capacity. You would also need spacers or a bit of wire soldering to get the cells to fit.

 

[zband]

It needs two AA's.

 

[Mr Happy]

Since the weather station likely has a very low battery drain, you could probably get by with anything. However, a pair of Energizer L91 lithiums would be your most reliable option.

 

[Woods Walker]

I have Eneloops in a external weather station, which is going tp be exposed to MI winter (think nighttime temp sometimes -10F)

Is this going to destroy my eneloops? Should I switch to alkalines for the winter?

Never used any NiMH batteries below 32ish however I have used alkalines around -20F and they really failed. Energizer L91 lithiums worked great at these temps in my Apex headlamp so guessing the same would be true for flashlights. I keep the Apex battery pack under my hat as it must help. Flashlights stored in my jacket pocket. Funny stuff happens below -20F. So guessing lithiums are your best bet.

Edit.

Don't count on sometimes -10F. I have seen the bottom fall out in places that people say don't get lower than that. However guessing a weather station would have good records. Layer your clothing and no cotton. Also DO NOT WEAR TIGHT FITTING BOOTS. Leave room for good socks and allow the blood to flow. Thinking you know all of this but sometimes I need a reminder.

 

[Nubo]

So no rechargeable option?

NiCd might work. If you cannibalize a solar walkway light you could even make the thing self-charging.

 

[Closet_Flashaholic]

You'll need to switch to Energizer e2 Lithiums for the winter.

+1

I have had a set of these in my weather station for over 2 years straight. Think Buffalo, NY. -20F in the winter, +95F in the summer (in direct sunlight).

FWIW, I will probably replace them this summer. I would like to use rechargeables, but for $5.00 (2 x AA) and and the IJW (It Just Works) factor, I consider it well worth the money.

 

[Hondo]

I'm just north of Detroit, and my weather sender unit has worked fine for the past few winters on alkalines. The inside unit got leaked on when someone turned off the wall switch to the socket it was plugged into. That caused the unit to run on the backup AA's, which killed them and was followed by two of four cells leaking. I changed the outside unit cells at that time too, which were pretty low, but not leaking. If you are not cheap (like me), you would get the best service, both in terms of longevity and likelyhood of leakage, from the e2 lithiums. But if rechargability is a big selling point, I would just use the Eneloops. They may not be able to deliver big current at low temps, but the unit does not need it (at least mine does not). I doubt that any significant damage to the cell would result from the exposure to the cold.