Battery types?

sevenhills

I bought some AAA batteries last week, Energizer Max. I was concidering rechargeable, but do they work out cheaper?
I believe some rechargeable batteries are a slightly lower voltage and don't always work with some things.
There are supermarket batteries and high power, Duracell - would it be better if the amp hour or some such discription. Instead of last xx longer?

RobM99

I only use rechargeable AA and AAA - never had a problem and been using them years!

[Deleted User]

Most batteries are marked with Ah and V.

An AAA battery is probably less than 2Wh, or 0.002kWh - so costs about 7 thousandths of a penny to charge - round it to one hundredth of a penny to massively over-account for losses in charging. 

edit: as pointed out by tallmansix below, I'm out by a factor of ten - so it's a tenth of a penny to charge your AAA battery.

[Deleted User]

I raised this question with OMRON Europe technical support re their BP monitors. I got this response back from them:

‘ All our upper arm monitors should use  4 X “AA” batteries 1.5V . Also we do recommend only “AA” alkaline or manganese batteries. This is due to they need 6v to accomplish the necessary power for the board and the connector board  (BT) and a stable current power. 

Apart of the voltage -1.5v- please take a look into the type:  If they are not alkaline or manganese batteries they may be not suitable. 

No rechargeable batteries or other voltages can be used in our devices. ‘

Given that GPs review BP medication based, in part, on home monitoring my wife is using the recommended batteries in her device.

QrizB

sevenhills said:

I bought some AAA batteries last week, Energizer Max. I was concidering rechargeable, but do they work out cheaper?

Rechargeables definitely work out cheaper for frequently-used devices.

I have a battery electric shaver. I have used it more-or-less daily for the last four years. A pair of alkaline AAs would last two months, so I'd have used 24 pairs - roughly £24 assuming Duracell or similar at £1 each.

Instead I bought two pairs of cheap rechargeable AAs for £4. They don't last as long - only one month - but fours years on and I'm stuill using the same ones.

I believe some rechargeable batteries are a slightly lower voltage and don't always work with some thinks.

Yes, if you've got particularly demanding devices regular rechargeable batteries won't work. Back when digital cameras used disposable batteries I had to buy expensive lithium AAs for mine - even branded alkaline AAs were worthless.

sevenhills

[Deleted User] said:

Most batteries are marked with Ah and V.

An AAA battery is probably less than 2Wh, or 0.002kWh - so costs about 7 thousandths of a penny to charge - round it to one hundredth of a penny to massively over-account for losses in charging. 

I got my magnifying glass out, voltage is displayed, but not Ah(AAA)

[Deleted User]

[Deleted User] said:

Most batteries are marked with Ah and V.

An AAA battery is probably less than 2Wh, or 0.002kWh - so costs about 7 thousandths of a penny to charge - round it to one hundredth of a penny to massively over-account for losses in charging. 

0.002kwh x 34p/kwh = 0.068p

~ 7 hundredths of a penny or 0.07p

Or 1 tenth of a penny (0.1p) doing the same rounding as you did for charging losses.

Doesn't change anything though, incredibly cheap in comparison to non-rechargeable batteries.r

[Deleted User]

[Deleted User] said:

[Deleted User] said:

Most batteries are marked with Ah and V.

An AAA battery is probably less than 2Wh, or 0.002kWh - so costs about 7 thousandths of a penny to charge - round it to one hundredth of a penny to massively over-account for losses in charging. 

0.002kwh x 34p/kwh = 0.068p

~ 7 hundredths of a penny or 0.07p

Or 1 tenth of a penny (0.1p) doing the same rounding as you did for charging losses.

Doesn't change anything though, incredibly cheap in comparison to non-rechargeable batteries.r

Yes, I had ten pence in a pound somehow!