While line/energy loss during charging sessions is understood, a few questions need to be clarified with existing EV owners based on their personal experience
BHPian Sachin26 recently shared this with other enthusiasts:
Hello EV Owners,
I am starting a new thread on behalf of a friend who I recently helped in deciding to purchase the Hyundai Creta EV 51 LR Excellence variant. The car is almost 45 days old with 2,000 KM on the odometer, and the first free service was completed today.
Energy Loss During Charging
In the last 45 days, two sessions of full recharge to 100% from 10% have been completed, along with a couple of recharges from 30% to approximately 80%. All charging was done on the common chargers of the society (7.2 kWh AC charger) set up by a third-party CPO (Electric Web). During these two recharge sessions (10% to 100%), the overall charging consumption was almost 56 to 57 units in total (invoice attached for reference), which is roughly 10 to 11 units more than the battery capacity of 52 kWh. This translates to almost 20 to 25% more than the actual capacity of the battery. While line/energy loss during charging sessions is understood, a few questions need to be clarified with existing EV owners based on their personal experience.
- Is it normal to experience 20 to 25% energy loss during a full recharge? Can other Creta EV owners share their experience?
- Is this figure different for different EV models? Can EV owners of other brands share their experience as well?
- Can this energy loss be different for different CPOs? What is the experience in general with reputed CPOs like Jio BP or Tata Power etc., operating in the market?
- Does energy loss differ for different charging speeds? (AC slow chargers in comparison to DC fast chargers vs. 16 AMP home socket?)
Response to the above questions is highly appreciated, and thanks in advance for all the guidance.
@Mods, a search for the above topic was attempted, but a thread specific to the discussion could not be found, so a new thread was started. If a thread already exists, kindly merge the same.
Here’s what BHPian lordtottuu contributed to the discussion:
On a 10–100% charging session on an AC charger, there are two areas where you’ll experience a delta between the two numbers:
- You’ll lose ~8–12% in AC->DC conversion and heat. On the 7.4 kW chargers at my community, I typically add 10% to calculate how much to add to my wallet, and I’m often short a bit.
- Charging above 80% is much less efficient. Various factors are at play here, including cell balancing and higher resistance at high SOC. The last 20% will easily make the total used power higher than the pack size.
If I remember correctly (and please let me know if I’m wrong), AC slow chargers are usually medium efficient, DC fast charging a bit better, and generic 16A boxes are probably at the lowest rung.
Meanwhile, BHPian varkey added this to the discussion:
In my experience with a Nexon EV Max with a 40.5 kWh battery pack, the AC charging loss was never been more than 10% (this would include the AC–>DC conversion losses, and additional energy spent on the cooling system depending on the weather, and also topup of the low-voltage battery).
For a recent 7kW AC charging session (Rebolt) from 13% to 100%, I was charged for 37.9 kWh. The actual battery capacity added, is 87% or 35.24 kWh. The loss was only 7.5% or so. Another session from 27% to 100%, Rebolt charged for 31.7 kWh. Actual capacity added is 73% or 29.57, loss still in the 7% range.
I’ve observed that the weather has a considerable impact on these losses atleast for the Nexon EV, as when the climate is cooler, the losses are relatively less too. When I charge in Kerala when the weather is hotter, I’ve seen it go up to 10%, and I can hear the cooling system kicking in as well.
As iamgyan mentioned, this looks like some issue with energy metering, 20-25% excess is definitely abnormal and you need to raise with the charger vendor.
Check out BHPian comments for more insights and information.
