RE: denali charger specs question

["Roger Stockton" <rstockton@delta-q.com>]

> -----Original Message-----
> From: Sam Uzi [mailto:samuzi@kcd.com] 
> Sent: May 31, 2002 3:39 PM
> To: evug list
> Subject: denali charger specs question

> Denali uses Hawkers, and they are claiming that their 
> proprietary 1.2kW charger can charge the battery (from 110v 
> outlet) to 90% in 20 minutes, and to 100% in 30 minutes 
> without harming the battery
> 
> is this realistic?  seems too good to be true

Assuming their 36V pack is a set of 13Ah Hawkers, the 90% in 20min part
could certainly be true: 30A for 20min is 10Ah.  100% in 30min without
harming the batteries is a bit more questionable, but might be doable.

My concern would be that there is real risk of venting one of the
batteries when recharging them at very nearly C/1 in a series string
unless the charger monitors the terminal voltage of each module rather
than just the total.

I see no heat sinks on their artist's concept of the not-yet-produced
charger and even if it achieves ~90% efficiency, I would be quite
surprised if they can sustain this output for much longer than 30min in
a <6lb package without it getting extremely hot.  Wonder if there is a
reason for only a 6month warranty?

The line I get a kick out of on their page is the statement "We have
pushed the mobile charger power envelope for over 4 years now...", yet
they have no picture of an actual charger product of their own and offer
a rather ordinary looking 22A 36V Schauer charger until such time as
their Downloader is available.

Cheers,

Roger.