Charging speed...

[Bish1402]

Is there a way to see what charging speed you a getting while charging....? I know the Tesla screen will tell you.. 2.5kwh, 6kwh etc etc.. Plugged into a supposedly 7kwh last week, to then calculate it was charging at about 1.5kwh!! 

[Bish1402]

25 minutes ago, Bish1402 said:

Is there a way to see what charging speed you a getting while charging....? I know the Tesla screen will tell you.. 2.5kwh, 6kwh etc etc.. Plugged into a supposedly 7kwh last week, to then calculate it was charging at about 1.5kwh!! 

It's handy so if you plug into a public charger,but then see your only getting 2kwh, you can, if possible switch plugs etc.... 

[CY Leung]

On 9/25/2022 at 6:57 PM, Bish1402 said:

It's handy so if you plug into a public charger,but then see your only getting 2kwh, you can, if possible switch plugs etc.... 

I rely on Lexus Link app to tell the charging speed. If it is showing 3h 10m (in the case HV Battery is empty), I know it is about 7kWh.  

[RXtoNX]

If a charge is taking 3hrs 10min then it is not charging at 7KWh since a full charge is around 14.6KW due to the Battery never reducing lower than 30%.

A 14.6KW charge on mine takes 2hrs 34mins

[Ken R]

Likewise. I have never had a charge lasting more than 2hrs 40mins.

[ColinBarber]

6 hours ago, RXtoNX said:

If a charge is taking 3hrs 10min then it is not charging at 7KWh since a full charge is around 14.6KW due to the battery never reducing lower than 30%.

If the Battery is at 30% then you need 12.67 kWh to get to full capacity as the Battery is rated at 18.1 kWh (excluding all the charging losses). The onboard charger is rated at 6.6 kW, in theory you could be putting 7 kW into the vehicle if the supply voltage is 245+ v. You may see times vary between location and time of day as supply voltage can vary quite a bit.

If you are seeing a charge time of between 2.5 and 3.25 hours then you are probably at the maximum possible. Anything beyond that and it would suggest that full capability hasn't been negotiated correctly and worth reseating the cable or try another charger.

[RXtoNX]

1 hour ago, ColinBarber said:

If the battery is at 30% then you need 12.67 kWh to get to full capacity as the battery is rated at 18.1 kWh (excluding all the charging losses). The onboard charger is rated at 6.6 kW, in theory you could be putting 7 kW into the vehicle if the supply voltage is 245+ v. You may see times vary between location and time of day as supply voltage can vary quite a bit.

If you are seeing a charge time of between 2.5 and 3.25 hours then you are probably at the maximum possible. Anything beyond that and it would suggest that full capability hasn't been negotiated correctly and worth reseating the cable or try another charger.

That’s a fair point Colin re the 12.67KW being 70% of the 18.1KW Battery capacity.
However a full charge on mine always takes 14.6KW as confirmed by both the hive apps and the Easee charger app, since my charger is not the normal BG one but was supplied by BG for reasons previously reported, always takes 2.5 hours overnight.

The Easee charger is capable of charging at a speed of up to 20KW/hr but of course the actual charging speed is governed by the car.

[ColinBarber]

34 minutes ago, RXtoNX said:

However a full charge on mine always takes 14.6KW as confirmed by both the hive apps and the Easee charger app

yeah, this is where we get into charging losses. The amount of energy consumed is more than the amount that ends up in the Battery due to losses in the cable, on-board charger efficiency, vehicle's on-board electronics controlling the charging using power etc. Typically a 10 to 15% loss is expected using these type of chargers.

[Harrier Man]

Are the losses consistent across the charging cycle or are they greater as the Battery nears 100%?

I'm wondering if it would be better to charge to, say, 90% when the opportunity arises.

[Harrier Man]

Although I don't have a lot of experience charging my 450h+, I have noticed that the charge completes an hour before the time I set in the charging schedule. Anybody else experienced this?

[ColinBarber]

11 hours ago, Harrier Man said:

Are the losses consistent across the charging cycle or are they greater as the battery nears 100%?

I'm wondering if it would be better to charge to, say, 90% when the opportunity arises.

It's consistent. Most losses come from resistance in the charging cable/connectors and converting mains AC into the correct DC voltage to charge the Battery rather than what state of charge the Battery is in.