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Old 07-17-2021, 12:51 PM   #31 (permalink)
S Keith
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Quote:
Originally Posted by Hersbird View Post
Well if you have say a 10kwh battery you don't pull just 2000watts out of a generator. You pull as much as possible and charge the battery, then shut off the ICE and use the battery, repeat. Normally you would want to size the generator to the load, but with the battery you can make that the big load and then bleed that with the usage.
It depends on the goal. If the goal is to use the least amount of gas per kWh, then using the ICE for any charging is folly. Generators are designed for power production at constant rpm in mind. They have a near linear efficiency to power relationship. They are MORE efficient at 100% than they are at 50%. Propulsion ICE aren't. They are designed for efficiency while propelling a vehicle, and they have a variable mass/fuel flow, rpm and power relationship.

The ONLY way this would be viable is if you made the charging occur AT the peak efficiency point for power and rpm of the ICE. Under all conditions, the ICE would NEVER beat the generator in terms of fuel burned per kWh due to the larger mass and increase inefficiencies. Additionally, the battery would need to be VERY robust to handle this charge current as you'd likely be charging the 10kWh battery in under an hour.

The only place the propulsion ICE would beat the generator is in pollutants. Generators are dirty.

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