Ansmann maxE
All rechargeable batteries lose charge over time once they are removed from a charger, this is known as “Self Discharge”.
For conventional NiMH type rechargeable batteries this is generally between 1% and 2% per day, though can be higher for the first few days.
As a result a rechargeable battery could have lost something like 50% of its capacity after a month of storage. This is often seen with digital cameras, where you put some freshly charged batteries in, take a few pictures, then put it away for next time. Next time ends up being a month or 2 later and the camera batteries are dead – really annoying.
Low Self Discharge (LSD) Rechargeable Batteries tend to have a self discharge rate of more like 1% – 2% per month making them much more suitable to this type of usage.
The down side of Low Self Discharge (LSD) Rechargeable Batteries is they tend to be a lower capacity, typically 2000mAh – 2100mAh for the AA size. This means they won’t last quite as long as a high capacity conventional rechargeable battery would if used intensively soon after charging.
As a rough “Rule Of Thumb” for AA rechargeable batteries, the cross over point is something like 2 – 3 weeks. So if you would ordinarily exhaust 2700mAh rechargeable batteries in less than 3 weeks, then stick with them, but if it would be longer than this then consider the Low Self Discharge (LSD) rechargeable batteries.
Low Self Discharge (LSD) rechargeable batteries are best for:
- Clocks
- TV Remote Controls
- Torches
- Flash Receivers
- Wii Controllers
- Xbox Controllers
- Kids toys
- Casual use cameras
- Solar Garden Lights
- Other low drain or occasional use products
2850 mAh AA
Nickel Metal Hydride or NiMH, Ni-MH type rechargeable batteries are higher capacity replacements to the generally poor performing Ni-Cd (Nicad) type rechargeable batteries.
These are available in all five battery sizes (AAA, AA, C, D & PP3) and can usually replace normal disposable batteries in just about every application.
Typical battery capacities are:
AAA (LR03) 800 mAh to 1100 mAh
AA (LR06) 1300 mAh to 2850 mAh
C (LR14) 2500 mAh to 4500 mAh
D (LR20) 2500 mAh to 10000 mAh
PP3 (9V) 150 mAh to 250 mAh
Performance of NiMH rechargeable batteries is in a different league to the early Ni-Cd rechargeable batteries, and anyone who hasn’t tried rechargeable batteries recently really should give them another go.
NiMH rechargeable batteries tend to perform particularly well in higher drain applications like digital Cameras, Flash Guns and radio controlled toys.
Nickel Cadmium or Ni-Cd, NiCd, NiCad batteries are the original type of readily available rechargeable batteries for the normal consumer or home user market.
There is lots of information on Wikipedia about the technical characteristics of these rechargeable batteries so there is little point in going into detail here, but the main things to understand are:
- Contain cadmium – nasty for the environment
- Suffer from memory effect if not fully discharged and charged regularly
- Relatively low capacity compared to new generations of rechargeable batteries
- Soon to be banned from import into Europe
Many people have been put off the idea of using rechargeable batteries because of poor experiences when using NiCd batteries, but things have moved on enormously since these were introduced.
NiCd batteries have pretty much been superseded by the much better Nickel Metal Hydride (Ni-MH) type of rechargeable batteries which offer higher capacities, no memory effect and no nasty chemicals.
So if you are still hanging on to some old NiCd batteries of have had a poor experience with them in the past, this you really should consider using rechargeable batteries again.
Have a look here for our full range.
Can Rechargeable Batteries be used in Smoke Alarms
Smoke Alarm Batteries
Yes, but perhaps the question should be:
“Should I use rechargeable batteries in a Smoke Alarm”
One of the problems with conventional rechargeable batteries is the self discharge – at between 1% and 2% per day this is higher than the drain from the smoke alarm itself.
So a conventional rechargeable will be pretty much flat after just a couple of months or so. This in itself is not such a problem as you can just take it out, recharge it and put it back in.
The real problem is how quickly the voltage drops off as the rechargeable battery approaches exhaustion. In most single use batteries the voltage drops off at a fairly consistent rate, so the low battery warning beep you get in a Smoke alarm can go on for weeks. Rechargeable batteries hold their voltage really well right to the end, but then drop off very quickly, this means you get the low battery warning for a much shorter time – This can be just a day or so, perhaps even just a few hours.
So unless you check your smoke alarm battery ever day, there is a real possibility of the rechargeable battery going flat without you ever knowing! – not a great thought.
So I think the answer is “Yes you can, but you probably shouldn’t“.
Instead I would suggest you use conventional Alkaline type batteries or, for extra piece of mind, why not look at using the ULTRALIFE Lithium PP3 type battery, this can last up to 10 years in a Smoke Alarm.
More details HERE
Link to this post: "http://www.tantronics.co.uk/blog/2010/01/can-rechargeable-batteries-be-used-in-smoke-alarms/"