View Single Post
Old 07-30-2012, 02:11 PM   #31 (permalink)
Cyborg ECU
California98Civic's Avatar
Join Date: Mar 2011
Location: Coastal Southern California
Posts: 6,299

Black and Green - '98 Honda Civic DX Coupe
Team Honda
90 day: 66.42 mpg (US)

Black and Red - '00 Nashbar Custom built eBike
90 day: 3671.43 mpg (US)
Thanks: 2,373
Thanked 2,172 Times in 1,469 Posts
Originally Posted by ecomodded View Post
I have not heard/ read about ah losses due to low amp charging. I am still under the belief that slow/ low amp charging is superior to fast / large amp charging. In short the fast charge is reported to dissipate faster. Could you enlighten me with some information or a link ?
I seem to have a gap in my knowledge bank.
Here's the content of my conversations with the Odyssey factory people, the three substantive calls with Bruce (plant manager) about my charging strategy, my alt on/off switch, and my driving pattern. He recommended a 25amp charger--instead of their 6amp charger--because the lower amp charger on the 40 amp hour battery I bought will not, long term, be able to fully charge the battery even if I only discharge 20%-25%. Over time, sulfation builds up more quickly and cannot be as easily corrected by the charger. It also cannot be rectified by the alternator, which has modestly too low voltage for effective charging of a 40ahr deep cycle battery. He also recommended I modify or swap my alternator for either higher voltage (to 14.7 or so instead of 14.3) or higher amperage (from 40 to maybe 70 or 90). The latter is only if I cannot have the alt modified for higher voltage. He told me about a rule of thumb he applies: assuming appropriate charging voltage up around 14.7, then the charger should be rated for amperage not less than 40% the amp hour rating of the battery. Lastly, the 25amp charger has three stages: charging, "finishing," and float, which apparently means different amounts of current and voltage.

Probably most things are debatable, so what do you think might be wrong, partly or entirely, in that set of recommendations?

See my car's mod & maintenance thread and my electric bicycle's thread for ongoing projects. I will rebuild Black and Green over decades as parts die, until it becomes a different car of roughly the same shape and color. My minimum fuel economy goal is 55 mpg while averaging posted speed limits. I generally top 60 mpg. See also my Honda manual transmission specs thread.

Last edited by California98Civic; 09-29-2012 at 10:17 PM..
  Reply With Quote