How much electricity and cost to charge battery

wissy

Esteemed Pedelecer
Jan 26, 2013
543
46
Wales
So... if I find out £0.?? Per watt or whatever it is called ;). How would I calculate how much it would generally cost in electricity to charge my newish, Bosch 400 thingie battery from almost empty?
 

tillson

Esteemed Pedelecer
May 29, 2008
5,252
3,197
It depen
So... if I find out £0.?? Per watt or whatever it is called ;). How would I calculate how much it would generally cost in electricity to charge my newish, Bosch 400 thingie battery from almost empty?
Not very much, but the actual cost will depend on your electricity tariff, the capacity of your battery and the efficiency of your charger.

Taking my electricty tariff as an example, I pay about 11p per Kilowatt Hour.

To find the capacity of your battery, if you don't already know it, multiply the Voltage by the Ampere hour rating. Again taking my Panasonic battery as an example, it's nominally 26 Volts and is rated at 10 Ampere hours. Therefore, 26 Volts x 10 Ampere Hours = 260 Watt Hours or 0.26 Kilowatt hours.

If 1 Kilowatt hour costs 11 pence, 0.26 Kilowatt hours will cost 2.86 pence. And that is the cost to recharge from completely flat to full. Someone will come along in a minute and point out that I haven't included losses and the actual cost is 2.97 pence. What we can conclude is that the electricity cost is so small when compared to the battery degredation / depreciation cost that we can forget all about it.
 

wissy

Esteemed Pedelecer
Jan 26, 2013
543
46
Wales
i was hoping that somebody would do it for me? :)

new battery
New charger
 

tillson

Esteemed Pedelecer
May 29, 2008
5,252
3,197
i was hoping that somebody would do it for me? :)

new battery
New charger
I don't know which electricity tariff you are on, but as a rough estimate, 4 - 5 pence to charge your battery from empty to full.
 

wissy

Esteemed Pedelecer
Jan 26, 2013
543
46
Wales
I just want to work it out..

i can find out how much I get charged for electricity per unit thing but then I need to know the next bit in formula to do with my new Bosch 2015 battery and using bosch charger... So far my formula is:

Price per thingie of leccy x battery thing and somehow charger gets into equation but don't know why = total price for full charge (ish)
 

wissy

Esteemed Pedelecer
Jan 26, 2013
543
46
Wales
Once i know that then I will work out 'depreciation' in excel but really methinks this means degredation ie battery life thing.. :). That is another question for after I get basic formula
 

wissy

Esteemed Pedelecer
Jan 26, 2013
543
46
Wales
Then need to compare with price per mile of petrol for my 72 vw camper and work out difference and saving... Based on petrol prices for last 2 months and onwards...
 

Alan Quay

Esteemed Pedelecer
Dec 4, 2012
2,351
1,076
Devon
In reality the cost of electricity is irrelevant.

If each charge cost's 8p (worst case), and you charge it 800 times, you have spent £64.

You have also exhausted the battery life, and completed many thousands of miles. The bike is now worthless.

The capital cost far, far out weighs the electricity cost.
 
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tillson

Esteemed Pedelecer
May 29, 2008
5,252
3,197
Then need to compare with price per mile of petrol for my 72 vw camper and work out difference and saving... Based on petrol prices for last 2 months and onwards...
Your battery is a 400 Watt hour Bosch?

Formula

400/1000 x electricity unit price = cost to recharge from flat.

You shouldn't be paying more than 12 pence per unit. If you are, you need to review your energy situation. Therefore:

400/1000 x 12 = 4.8 pence per charge from completely flat.

That battery costs £545 to buy from 50 Cycles. If it lasts for 750 charging cycles, that works out at 73 pence per charge, which dwarfs the cost of the electricity.

Put it another way, over the life of the battery, you will spend in the region of £36 on electricity and £545 on a replacement battery. So you can forget electricity cost, in the wider scheme, it's nothing.

Some Ebikes aren't cheap to run, particularly those with expensive batteries like a BionX where battery cost can be £1.40 per charge!
 
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Cyclezee

Guest
Then need to compare with price per mile of petrol for my 72 vw camper and work out difference and saving... Based on petrol prices for last 2 months and onwards...
Hi Wissy,
The bottom line is whatever calculations you do, the running of your bike is going to be peanuts compared to your VW camper.
In addition to petrol you could also factor in insurance, road tax, servicing, tyres etc., etc.
Then there are non financial costs e.g. the stress of motoring etc.

You may find this interesting http://www.bbc.co.uk/news/health-29175088
 

wissy

Esteemed Pedelecer
Jan 26, 2013
543
46
Wales
In reality the cost of electricity is irrelevant.

If each charge cost's 8p (worst case), and you charge it 800 times, you have spent £64.

You have also exhausted the battery life, and completed many thousands of miles. The bike is now worthless.

The capital cost far, far out weighs the electricity cost.
Not if it has replaced my obly other mode of transport.. A 72 vw camper which did 300-300 km/full tank (fuel gauge never worked in 21 years :) ). So I will need to then work out size of my tank and mph and litres and price of petrol and then compare.. But I do know I am saving a hefty amount of petrol a month from using my pedelec to work and back .. 15 miles a day.. So about £200-£250 saving in petrol a month just to work.

And then I need to work out how many years I need to cycle to work and back to pay for the £7k+ restoration ...
 

wissy

Esteemed Pedelecer
Jan 26, 2013
543
46
Wales
Hi Wissy,
The bottom line is whatever calculations you do, the running of your bike is going to be peanuts compared to your VW camper.
In addition to petrol you could also factor in insurance, road tax, servicing, tyres etc., etc.
Then there are non financial costs e.g. the stress of motoring etc.

You may find this interesting http://www.bbc.co.uk/news/health-29175088

No stress driving my vw camper to work whatsoever .. Ever! :)

Much more stress cycling. Way more. So many dangerous nutters in cars.. One day they will go head on in the lane.. Bound to happen but I have succumbed to buying a helmet... :( blydi thing has holes in it!! Useless in Welsh weather....
 

wissy

Esteemed Pedelecer
Jan 26, 2013
543
46
Wales
Your battery is a 400 Watt hour Bosch?

Formula

400/1000 x electricity unit price = cost to recharge from flat.

You shouldn't be paying more than 12 pence per unit. If you are, you need to review your energy situation. Therefore:

400/1000 x 12 = 4.8 pence per charge from completely flat.

That battery costs £545 to buy from 50 Cycles. If it lasts for 750 charging cycles, that works out at 73 pence per charge, which dwarfs the cost of the electricity.

Put it another way, over the life of the battery, you will spend in the region of £36 on electricity and £545 on a replacement battery. So you can forget electricity cost, in the wider scheme, it's nothing.

Some Ebikes aren't cheap to run, particularly those with expensive batteries like a BionX where battery cost can be £1.40 per charge!

Gosh.. It is that cheap to charge it? I would never have thought that.

Is there any way to kniw how many charges a bosch battery has had / has left.

Also. I have a spare one .. Meant for my other brand new replacment bike... From 2014 though so guess it may not be as 'recent' as my 2015 performance haibike's battery although they are same model shape thing.. So... Should I be charing this 'spare' every now and then, using it or leave it alone until I exhaust this one in a few years??
 

Alan Quay

Esteemed Pedelecer
Dec 4, 2012
2,351
1,076
Devon
Not if it has replaced my obly other mode of transport.. A 72 vw camper which did 300-300 km/full tank (fuel gauge never worked in 21 years :) ). So I will need to then work out size of my tank and mph and litres and price of petrol and then compare.. But I do know I am saving a hefty amount of petrol a month from using my pedelec to work and back .. 15 miles a day.. So about £200-£250 saving in petrol a month just to work.

And then I need to work out how many years I need to cycle to work and back to pay for the £7k+ restoration ...
The point is, that electricity cost is tiny compared to the other costs.

Let's say you ride 20 miles a day, 5 days a week, over 3 years. That's 15000 miles,
And 780 charges.

Say you buy a £1000 bike. After 3 years it nearly worthless, so we will write the cost off. The battery will be knackered.

During those 15000 miles you will need to do maintenance on your bike:

6 sets of quality tyres: £40 x 6
Brake pads: £20 x 15
Chains, sprockets x £30 x 4

I make that £1660. There are likely to be additional costs, perhaps waterproofs, servicing labour, sundries. So as you see, the £50 or so in electricity cost is insignificant.

All in all, 10p/mile is a reasonable price IMHO.