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Old 08-23-2018, 10:02 AM   #31 (permalink)
Ecky
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Join Date: Dec 2011
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ND Miata - '15 Mazda MX-5 Special Package
90 day: 39.72 mpg (US)

Oxygen Blue - '00 Honda Insight
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Quote:
Originally Posted by mpg_numbers_guy View Post
Electrical noob question...why set the PSU to 14 volts when the battery is designed to run at 12 volts?
Forgot to answer this. A 12v battery is less than 50% charge at 12v, and they don't like being at low charge. At full charge it's higher than 12.8v, and in order to charge it, you need to supply the battery higher voltage than it currently has. I suppose you could probably run the system as low as ~13v and everything would work fine, but it's standard for alternators to provide between 13.8 and 14.2v.

In my ebikes, a "72v" battery is actually around 84-85v when fully charged, and in the 60's when close to empty.

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