What batteries is best to use for a sensor that sleeps most of the time?

[Cliff Karlsson]

I am planning to build a couple of sensors that will be used for example reporting temperature every 15th minute, reacting to a button and maybee one in my mailbox lid that would use a accelerometer/compass/pir or similar to react to lid opening.

All of these functions I guess would only require the arduino to be awake for a minimal time every day. What kind of batteries would be best to use for having as long battery time as possible? Li-po,Li-Ion or any other?

[sundberg84]

I use standard 2xaa and think i will be online between 9-12 months. Report every 15min. There is many threads in this forum about this.

[scalz]

I agree too. I prefer 2xaa or 2xaaa. coin cell is not very good for discharge rate and does not support well high power consumption. Lipo are best, but I am little afraid of burning stories even if it is usually with bad quality lipos. but I am not expert...just my point of view.

[Cliff Karlsson]

ok, but what kind of battery technology regular, nimh or nimh2? I noticed that rechargeble aa batteries is 1.2V vs ordinary 1.5V

[scalz]

I think I would prefer the regular alkaline. It depends of your application too. But if you are interested, here some links:
http://lenpenzo.com/blog/id710-why-rechargeable-batteries-are-rarely-cost-effective.html
http://www.greenbatteries.com/battery-myths-vs-battery-facts-1/
http://michaelbluejay.com/batteries/rechargeable.html
and there are lot of others links. it is very basic explanations, but if it can help you in your choice...

[bjornhallberg]

Another vote for AA/AAA. I have one motion sensor node that has survived outdoors for almost a year now on the same pair of AA, and it doesn't even have a regulator ... it surprised me a lot. Go for alkaline. Low self discharge nimh may be better, but they cost a lot.

[NeverDie]

Disposable lithium AA batteries (AFAIK much safer than the rechargeable) would last longer than disposable Alkaline batteries in a high drain scenario. Does it confer any significant advantage in the very low current scenarios that would characterize a MySensor? IIRC, the answer is "some but not much."

[Andy Pep]

i use 2cell 7.4 volt recycled laptop battery packs for my projects thay have a natural discharge of 5% a month but do some reading and research on how to handle and charge them...and you should be fine..plus recycleing lappy batterys is good for the enviroment..and you also learn about the new breed of batterys and cells