# Forums

## Long range Model 3 only got 60kWh Battery?

Hi -

I am trying to extrapolate the battery capacity from mileage since last charged. The approach I took was to charge till 90%, and drive until 40% of battery, and look at the "mileage since last charged" to see how much power been consumed.

I did the test multiple times and got result between 60-65 kWh constantly for my long range Model 3. From the spec I was expecting 75kwh.

I am wondering if it is possible that my long range model 3 somehow is set to mid-range by software (which has 66kwh batter)? Is such thing even possible? Or does anyone have any other explanation?

SCCRENDO | 16 marzo 2019

It’s about a 74 kWh battery. But some is reserved for a below zero reserve and another portion for anti-bricking. I have calculated it in the past (which can be calculated over a long distance by miles taken off the battery and kWh hours used). We use less than 250 Wh/mile which is more than 4 miles per kWh. I have done these calculations for my 85S as well in the past.

SCCRENDO | 16 marzo 2019

You need to do the calculation on a long distance without stopping and preferably begin at 100% and run it down as low as possible.

findekano | 16 marzo 2019

The math does not adds up though. If only 65kWh of battery is usable, the range would have been 65*1000/240 = 260 mi, while the claimed range is 310mi, which indicates 74.4kWh *useable* battery. The physical battery capacity should go reasonably beyond that.

Firaz.ashraf | 16 marzo 2019

My understanding is that thebBattery capacity on Long Range is rated 80.5kW of which 78kW is expected as usable.
You cant do a simple linear extrapolation from change in % charge/miles as not all miles are driven equally.
Why dont you just monitor kW to charge and that tells you what each % is worth (or alternatively, monitor how long is takes for changes in % charge based on whatever charge speed you are using). - all my observations are very close to 78kW capacity and I use 80kW capacity to do any approximations top of my head

Bighorn | 16 marzo 2019

72.8 kWh usable of 80.5
You can’t do this test in multiple legs.

findekano | 16 marzo 2019

to Firaz.ashraf - that's exactly what I did. I am not looking at % change/miles, I am looking at ^ changes/power_used. For example, I tracked the battery usage dropped 50% since last charge, and the dashboard board says 30kWh used since last charge - which indicates the usable battery capacity is 60kWh.

to Bighorn - thanks for the response. could you please response what 'multi-legs' means in this context?

Bighorn | 17 marzo 2019

Accurate measure must be done in one continuous drive. If you do it over several trips during the day or over multiple days, it will underestimate true capacity.

jjgunn | 17 marzo 2019

90% to 40% .... You've used 50% of the battery.

Using Bighorns numbers 72.8 / 2 = 36.4 kWh

As Bighorn stated, multiple trips over multiple days will not give you accurate measure of true capacity.

What are you missing? Think about it ...

Seat heaters, the heater itself, sound system, flooring it. AC while wife is in the store shopping. Contributes to usage while you're standing still.

It's the equivalent of an ICE car idling = 0 MPG

Bottom line. I'm pretty sure your car isn't software limited.

Bighorn | 17 marzo 2019

@jj
All the auxiliary stuff gets counted while the car is on. Vampire drain and powered things like battery cooling or cabin overheat protection are not when the car is off.

findekano | 17 marzo 2019

Thanks @jj @bighorn. Now it makes more sense. I'll find chance to do a long trip and see what happens :-)

I was expecting the power usage due to AC/seat heater/etc is counted in metric showed in 'power used since last charge', but apparently it may not.

Bighorn | 17 marzo 2019

All those things are included as long as the car is on. It lowers your efficiency but it’s still measured as energy consumed