View Single Post
Old 07-11-2014, 07:42 AM   #8 (permalink)
oldtamiyaphile
Master EcoModder
 
oldtamiyaphile's Avatar
 
Join Date: May 2009
Location: Australia
Posts: 1,510

UFI - '12 Fiat 500 Twinair
Team Turbocharged!
90 day: 40.3 mpg (US)

Jeep - '05 Jeep Wrangler Renegade
90 day: 18.09 mpg (US)

R32 - '89 Nissan Skyline

STiG - '16 Renault Trafic 140dCi Energy
90 day: 30.12 mpg (US)

Prius - '05 Toyota Prius
Team Toyota
90 day: 50.25 mpg (US)

Premodded - '49 Ford Freighter
90 day: 13.48 mpg (US)

F-117 - '10 Proton Arena GLSi
Pickups
Mitsubishi
90 day: 37.82 mpg (US)

Ralica - '85 Toyota Celica ST
90 day: 25.23 mpg (US)

Sx4 - '07 Suzuki Sx4
90 day: 32.21 mpg (US)

F-117 (2) - '03 Citroen Xsara VTS
90 day: 30.06 mpg (US)
Thanks: 325
Thanked 452 Times in 319 Posts
Quote:
Originally Posted by redpoint5 View Post
I'm curious if a lead acid battery dissipates energy even though it is already at full charge. If it does, I wonder how that compares to a LiFePO4 battery considering lithium chemistries require current flow to cease when full charge is reached.
Once LA batteries approach full charge their charge acceptance begins to drop. Modern "smart' alternators look for this drop in charge acceptance to determine the level of charge in the battery (when the alt. is running voltage is pretty much a constant 13.8v regardless of battery charge).

I do believe the excess current can only become heat, much like when you bench charge a LiFe and it gets warm as it gets full.

How would you quantify it? It seems more like something to do on a bench than in an engine bay, which would give you far greater control over variables. You could possibly spin up an alternator with a power drill, and add load via lights or 12v motors.
__________________






  Reply With Quote