Kitz Forum
Computers & Hardware => Other Technologies & Hardware => Topic started by: aesmith on March 22, 2020, 04:38:52 PM
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The outdoor unit of our weather station dropped dead in the last day or so. First check was the batteries of course, and it looks like one is dead as it was showing only 0.2 V compared to the other two at 1.5 or so. They are rechargeable alkaline AA cells which is not something I've used or ever seen before. I understand they're better at low temperature. Does anyone know anything about them, for example where to source replacements? And would using NiMH cells be OK in the medium term, or would this cause damage either to the cells or the charging circuitry?
Thanks, Tony S
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I think you're best looking at the manufacturers information and sticking to whatever type they recommend. I'm sure the retailers of your station should be able to supply what you need.
Stuart
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Not sure on this one, but I'd tread carefully. A possible issue is that Alkaline cells have a nominal voltage of 1.5V, whereas NiMH and NiCad are nominally 1.2V. That may mean different the charger would be incompatible, but a quick google has failed to confirm.
I'd be surprised if you encountered any problem using NiMH in the weather station as long as you use a charger designed for NiMH, rather than the one for Alkaline. Although the initial voltage is lower, NiMH and NiCad tend to stay at a fairly stable 1.2V throughout their discharge, reaching a cliff-edge when exhausted. In contrast a 1.5V alkaline tends to gradually decay down to 1.0V before petering out.
I find 'BatteryUniversity' to be a useful source of data. No answers, but a few mentions of reusable Alkalines...
https://batteryuniversity.com/learn/archive/whats_the_best_battery
https://batteryuniversity.com/learn/archive/will_the_reusable_alkaline_battery_have_a_future
I think you're best looking at the manufacturers information and sticking to whatever type they recommend. I'm sure the retailers of your station should be able to supply what you need.
I wouldn't disagree with Stuart's advice either, if it's an option.
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Cheers. I've emailed the original supplier (Maplin) although I notice they no longer list this product. If they don't reply or can't comment it's going to be a matter of tracking down the OEM or any other brand names it was sold under. The batteries are charged in the outdoor unit, from a solar panel.
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Cheers. I've emailed the original supplier (Maplin) . . .
I thought Maplin became defunct, sometime in the past twelve months . . . :-\
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The company still exists online, but it's a shadow of its earlier self.
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The company still exists online, but it's a shadow of its earlier self.
Ah, I see. Thank you.
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No final response from Maplin yet. It drove me nuts trying to find them myself, aside from the fact that a search for "rechargeable alkaline battery" even enclosed in quotes, returns every rechargeable battery of any sort, and every sort of disposable alkaline as well. And the few products I saw actually advertised as "rechargeable alkaline" by the retailer, actually turned out to be NiMH when you look closely.
The few places offering exactly the right thing seems to be (a) in America and (b) out of stock, for example https://www.ambientweather.com/amws1000batt.html
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Based on the links I posted earlier, ‘reusable’ rather than ‘rechargeable’ might bring more hits?
I wish you well with Maplin, but I’d not hold my breath. It looks very much to me like an opportunist has simply bought the trademarks and rights, and is using the website to promote random tat. It is unusual in such circumstances for the new owner of a defunct business to show any interest or inclination to assist or support customers of the old company. :(
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I think these would do the trick:
AmazonBasics AA Industrial Alkaline Batteries (Pack of 40) https://www.amazon.co.uk/dp/B07MLFBJG3/ref=cm_sw_r_cp_api_i_uf6EEb37C04Q8
From what I’ve read, there’s nothing special, chemistry-wise, about rechargeable alkalines. They’re just regular alkalines with the enclosure beefed up to prevent leakage during charging.
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AmazonBasics AA Industrial Alkaline Batteries (Pack of 40) https://www.amazon.co.uk/dp/B07MLFBJG3/ref=cm_sw_r_cp_api_i_uf6EEb37C04Q8
I may be wrong but from a quick read they do not appear to be rechargeable cells. :-\
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I'm sure 'Alkaline Batteries' are Not Rechargeable, as they will get hot and explode :'(
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I'm sure 'Alkaline Batteries' are Not Rechargeable, as they will get hot and explode :'(
Actually, to an extent, I agree with displaced...
From what I’ve read, there’s nothing special, chemistry-wise, about rechargeable alkalines. They’re just regular alkalines with the enclosure beefed up to prevent leakage during charging.
I even seem to remember the matter being discussed on these forums by a highly respected contributor with whom I think I disagreed at the time. We’ve not seen him for a while and so I won’t name him, unless he reads this and cares to contribute. ‘He’ is of course used in the gender neutral context, I may be talking about a ‘her’ too.
Would I risk it myself? In a cordless phone in the landing, no I would not, largely out of concerns over home insurance. In a remote weather sensor in the garden... maybe. :)
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I'm sure 'Alkaline Batteries' are Not Rechargeable, as they will get hot and explode :'(
There are chargers for standard alkaline batteries and they supposed do work There's an interesting look at it here (https://geekprepper.com/recharge-alkaline-batteries/).
One interesting bit that could explain its use here is:
Usable for hundreds of times – This is possible for the rechargeable alkaline battery if you recharge it after only 25% of its entire capacity is consumed.
That could explain why it was used in a solar powered weather station. The greater capacity gives it a better chance of never losing more than 25% of its charge.
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I understand that this chemistry is chosen because it has a wider temperature range. I don't want our weather station to stop working when it drops below -10 Deg C or whatever the relevant temperature is.
I've found them on Ali Express, not my favourite supplier but that was where I managed to find tagged NiCD cells in the past, and bits for the tractor as well. https://www.aliexpress.com/item/32912785744.html