Re: Battery lifespan

the_dawggie wrote:
>
>I'm curious about battery life on SI verses CI engines. On a diesel
>you hit the thing
>with around 70 amps for glow plugs for near 10 seconds before
>starting, then I'm
>not sure on the current for the starter, however the initial stroke is
>doing 22:1
>compression - of course the next stroke is more air spring.

Most diesel starters have reduction gears, which significantly reduces
the load on cranking.  Glow plug current isn't particularly severe
compared to cranking current... which is what normally kills 'em.
Likewise high underbonnet temperatures and vibration (or an
overcharging regulator).

Apart from their needing a larger capacity battery to start with (to
handle the glow plugs) I've never found any significant differences in
battery life with diesels.  Those with 24 volt systems last much
longer than anything else.

-- 
John H