Wrong kind of electric. Part II.

Okay, I am using the right kind of batteries.


So what's wrong with batteries other than alkaline that makes them unsuitable for use in smoke and heat alarms, what is E-Block and what makes a battery suitable for use with transistors?


Andy Betteridge.

Different chemistries perform differently - slightly different initial voltages, very often very different curves as they discharge or age, sometime different performance given large or sudden changes in load (e.g. when an alarm sounds). I had a lot of problems with some early rechargeables for instance as their terminal voltage quickly dropped to a level where some equipment would object even though there was plenty of power left in them, and being labelled with the correct "nominal" voltage.

   - Andy.

what is E-Block


A generic size. 

and what makes a battery suitable for use with transistors?


It is actually in the singular in your image, as in transistor radio. Don't tell me you didn't listen to 208 under the bedclothes with a 10 shilling pocket sized transistor radio using one of these compact 9 V batteries in the 60's?


Regards


BOD

I had a crystal radio that was a hand me down from my cousin :-)

E-Block is the name in some countries for what we used to call a PP3. The reason they specify alkaline is the long shelf life. Zinc Carbon (or in reality these days Zinc Chloride) batteries are still depressingly common. In the heat of a mains powered smoke alarm (they do generate a little, enough to cause the temp to be a fair way above ambient inside the casing), can cause those to leak in short order.


It's basically being nice to the consumer, 'don't destroy the thing that might save your life by buying an asda smart price zinc battery'


Trade price for the 'right kind of battery that you show the box of there is about a pound a unit inc vat round here, hardly a lot for a year's protection :)


And re: radio, with me it was 648 medium wave under the covers, always liked the BBC World Service

I have bought sixty batteries in the last fortnight, several of the HMOs already have alarms with sealed for life batteries, but I have replaced over twenty alarms as well in the last fortnight.


In the last month I have found two alarms that were twenty two years old and actually finding a house or HMO with compliant alarms is highly unusual. 


It’s difficult to believe that people either seem to think alarms and batteries last forever and/or have absolutely no understanding of basic smoke alarm maintenance, particularly when the “people” are property professionals.

Slightly (ok, a lot) off topic. We have a Chinese lucky cat that constantly waves his left paw using a mechanism powered by a couple of AA batteries. We have found that he waves for longer with Duracell batteries, compared to any other brand we have tried . . . 


Regards,


Alan.

This sketch then .. actually   'ever cell' to avoid any sort of lawsuit from battery makers. clearly less worried about law suits from Russian leaders.

Actually the cylindrical alkaline cells still use zinc, but rather than make the metal the big outer electrode (the older cells had just the zinc as the container and have a carbon rod up the middle, so the higher resistivity electrode is also the smaller area one), in an alkaline cell, the low resistance zinc is made the central column, and it is surrounded by anode material, normally mangnese oxide on the inside of a metal jacket. The alkaline part just keeps it conductive and has a lower resistance than alternative electrolytes.

As in the carbon zinc cell, you are dissolving zinc on the negative terminal to create zinc ions and push electrons around.

The manganese anode regroups from one oxide form (MnO2) to another (Mn2O3) so in normal use no free gas is liberated.

They are not supposed to be recharged, but with careful control of waveform they can be used several times.