Dobeman2000 said:
So, with all that said when the car's battery reads say 30% and the mileage is at 10 which should I pay attention to?
The only number that really matters is the % State of Charge (%SOC) because that is a measurement of the amount of energy left in the battery. The miles remaining is simply a guess by the car how far you can go on that energy left based on your recent driving pattern. That's why we call it a "Guess-o-meter" (GOM) here. If you were to drive at higher speeds, or the weather got colder, snowier, windier, you might get fewer miles than the GOM reports. If you were to slow down or turn the cabin heater off, you would likely get more miles than the GOM reports.
The problem is determining how far you can go on that "30%". And that takes experience. As the weather cools you will get fewer miles per kWh in the battery, meaning fewer miles per % SOC. Driving faster will give fewer miles/kWh. Driving in snow or in windy conditions — save for trips all downwind — will give fewer miles/kWh. Using the cabin heater can significantly lower the miles/kWh you get.
You can get an idea of how efficiently you are driving by resetting your dash miles/kWh display before each trip. The number you get in summer will be significantly higher than the number you get in winter. You need to adjust your range expectations accordingly.
To give you a rough idea of how far you can go under a given set of weather conditions you can do some arithmetic: A new LEAF has roughly 22 kWh usable charge (actually more like 22.5 kWh but most people don't want to get to a low enough %SOC to use it all). So, each kWh is about 4.5%. If you are getting about 3.5 miles/kWh on a trip, that means that 30% would be something like (30%/4.5%) x 3.5 miles/kWh = 23 miles. Not that you would want to take the car all the way to 0% (I think it only goes down to 1-2%, but am not sure). But that gives you an idea of how far you can go.
So, it all depends on what sort of mileage efficiency you are getting. And only you can determine that by measuring it. Besides the mileage efficiency meter on the dash you can also keep an eye on how far you go for a certain amount of charge. If, for example, you charge to 80% and drive 35 miles to get to 30%, you used ((80% - 30%)/4.5) = 11.1 kWh to go 35 miles, which is about 3.15 miles/kWh. However, please bear in mind that the %SOC readings aren't completely linear, especially between 80% and 100%, for reasons I'd rather not try to explain.
Nevertheless, just keeping track of how much charge (in %) you use to go a particular distance will give you a rough idea of how far you are going to be able to go
under the same driving conditions (speed, weather, heater use, and the like). If it looks as if you might not make your destination you have some options:
1) Slow down. This will increase mileage efficiency by a lot.
2) Turn off the heater, if it is being used.
3) Find a charge station.
It also helps to become a more efficient driver, but that takes practice and isn't something that can be learned at the last minute.
Don't know if that really answers your question, but it was a little vague...