[ausev] DC/DC & Batttery

[Chris Robison]

On Tue, March 13, 2007 1:29 pm, Gil Dawson wrote:
> In my Chevy S-10E, the computer boots from the car battery.  Then the
> computer makes everything else happen.

In most cases, the vehicle controller requires low voltage power
(12-14VDC) to operate its internal logic. In these cases, this power can
come from the "SLI" ("starter, lighting and ignition" in ICE terms)
battery as it does in your S10, and usually in an EV this battery is
charged by a DC/DC converter.

You can do without the SLI battery even in the usual situation where the
controller requires low voltage power, but you will need to have your
DC/DC converter wired to provide power continuously from the main pack,
even when the car is off.

There are other arguments in favor of doing this -- eg. reducing stress on
the converter's capacitors, etc due to switching it on and off. But there
will be a small continuous drain on the pack if it's left on.

Better in my opinion to have an SLI battery and have the DC/DC converter
on only when the car is on. Others on this list and elsewhere may have
different opinions.

  --chris