Charging Rate using my Granny!

[bwanamdevu]

I decided to check just how many miles per hour my Granny Charger would deliver. Experiment conducted over two days, yesterday and today.
My MG5 Long range was charged from its existing 40% to 100%. Checked on the mileage delivered over two lengths of time, results as follow….

The rate delivered yesterday was approximately between 7 and 7.2 mph over a period stretching through the late morning, afternoon and until midnight. Weather fairly warm for the time of year, between 8 and 11C. Little wind. Charged 40% to 93%
Rate delivered this lunchtime for about 3hrs was 8.5mph till it was up from the previous 93% to 100%. Colder and much windier! 5-6C.

Something in my little brain suggested beforehand that it would deliver a greater mph on warmer days but in this very unscientific experiment, the opposite occurred. Any charging experts out there who can comment on the results? Is the rate temperature dependent? Time of charge? %age left affects the rate? Other factors that my EV uneducated brain has not considered?

Please read, ponder and give me your thoughts. I shall perform this experiment periodically over the year to come.

 

[Jomarkh]

When you started the charge at midday then the battery would only be getting warmer until mid night.
When you charge above 95% the rate drops off and after 100% the battery will start a balance and draw about 500w.
I think you have to do the test from the same starting percentage and at the same time of day.

 

[bwanamdevu]

When you started the charge at midday then the battery would only be getting warmer until mid night.
When you charge above 95% the rate drops off and after 100% the battery will start a balance and draw about 500w.
I think you have to do the test from the same starting percentage and at the same time of day.

Jomarkh, I think that you have completely misunderstood the basic idea behind this test. The idea was to investigate how the charging rate was altering dependent upon the amount of charge already accumulated, that is, for example, did the the car charge faster between 40-50% and slower between 70-80% and slowest when it was charging the last 10% between 90 and 100%. Doing a test repeatedly, starting at the same starting %age would accomplish nothing of significance.

 

[Jomarkh]

Did you stop it at 100% or after the battery balance was completed?
Are you trying to find when to charge by temperature, would it not be better to have a set time that it is plugged in say 5 hours at different times of the day or from a set percentage range to complete?
I too would have thought starting with a warm battery would charge faster.
Did the current drawn by the change much on your IHD for your smart meter?

 

[bwanamdevu]

Did you stop it at 100% or after the battery balance was completed?
Are you trying to find when to charge by temperature, would it not be better to have a set time that it is plugged in say 5 hours at different times of the day or from a set percentage range to complete?
I too would have thought starting with a warm battery would charge faster.
Did the current drawn by the change much on your IHD for your smart meter?

Hi Jomarkh,
Can‘t seem to make you understand the basic premis behind the very unscientific experiment that I carried out! It was purely to have a brief analysis of how the charging rate varied as charge built up and accumulated in the battery. Nothing else. I find it hard to believe that you have not read and understood what I have previously written.

 

[smokie]

Well to be fair (and I don't think you are being!) Jomarkh has risen to the challenge in your first post, to "read, ponder and give me your thoughts.", which is more than the rest of us have.

I didn't because I don't really get what you are driving at (pun intended).

 

[Gomev]

This is a very personalised test.
The mph for charging is quite simple, charger speed, granny is 2.3kW for an hour (excluding losses) would be 2.3kWh. multiplied by your own mile/kWh.
For most people that will be in the region of 2.3 x 3.5 =c.8 mph charge added.

 

[ALANB]

I decided to check just how many miles per hour my Granny Charger would deliver. Experiment conducted over two days, yesterday and today.
My MG5 Long range was charged from its existing 40% to 100%. Checked on the mileage delivered over two lengths of time, results as follow….

The rate delivered yesterday was approximately between 7 and 7.2 mph over a period stretching through the late morning, afternoon and until midnight. Weather fairly warm for the time of year, between 8 and 11C. Little wind. Charged 40% to 93%
Rate delivered this lunchtime for about 3hrs was 8.5mph till it was up from the previous 93% to 100%. Colder and much windier! 5-6C.

Something in my little brain suggested beforehand that it would deliver a greater mph on warmer days but in this very unscientific experiment, the opposite occurred. Any charging experts out there who can comment on the results? Is the rate temperature dependent? Time of charge? %age left affects the rate? Other factors that my EV uneducated brain has not considered?

Please read, ponder and give me your thoughts. I shall perform this experiment periodically over the year to come.

To be honest I doubt if the rate will change noticeably.....it's a simple formula of voltage times current. The incoming will always be controlled by the home supply which can't vary unlike the rapids we use. The sweet spot for battery charging is around 23C and the bad spot is sub 0.