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Old 11-27-2007, 02:10 PM   #421 (permalink)
MetroMPG
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Join Date: Nov 2007
Location: 1000 Islands, Ontario, Canada
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Blackfly - '98 Geo Metro
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Last 3: 70.09 mpg (US)

MPGiata - '90 Mazda Miata
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09-11-2007, 11:39 Am

Quote:
MetroMPG The voltage sags pretty low under even light-modest loads. I've read it's best to try to keep the batts above 5.75v (individually) under load, and definitely go no lower than 5.5v. I can't accelerate at "normal" traffic rates and keep the voltage above 5.75, even on a fresh charge.
Crud! I keep mixing this up. So, correction:

5.25v is the conservative lower limit of sag under load for a flooded golf cart type batt, not 5.5v.

(Below 5.25v, you have no guarantee that an individual cell isn't approaching zero, and about to reverse polarity - pretty much wrecking the battery).

So trying to keep sag above 5.75v, while good for range and battery-friendly, isn't strictly necessary.

Which means that, when needed, I can accelerate more rapidly than I have been and not fear for the lives of the old floodies.

Also, using 5.25 as the lower limit effectively extends the car's range. Time for another range test!

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