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Re: [EVDL] final email about "problems Electro Automotive"

Collin Kidder <[email protected]> wrote:
> On Tue, Nov 2, 2010 at 12:11 AM, EVDL Administrator <[email protected]> wrote:
>
>>
>> The only solution I can see is for some open-minded hacker (in the good
>> sense) to reverse engineer the Zivan firmware so users can tweak it
>> themselves.
>>
>> David Roden - Akron, Ohio, USA
>> EVDL Administrator
>>
>>
> Well, there's two possibilities:
>
> 1. Rewrite the firmware
> Usually people go to great lengths to protect the firmware in their
> products. It's not, in general, possible to tweak or get at the existing
> firmware. A totally new firmware has to be written based just on how the
> circuit board looks and what components appear to be on it.

> The bottom line is that we'll never know for sure what the real situation is
> until someone decides to have a warranty voiding day. Any takers? ;-)

Paul Compton reverse engineered one of these chargers several years
ago. I think I have a copy of his schematic somewhere. Anyway, the
point I want to make is that, based on my recollection, the
microcontroller has fairly limited control over the charge profile, I
think it basically acts as a timer to switch between different steps
of voltage and current that are set in hardware. I guess it "evolved"
from earlier chargers which had hardware timers as well.
Not flexible or easy to work with, and that's one reason these
chargers were never well suited for charging AGM batteries like
Optimas.

The sensible option looked like making a new, simpler logic board
which allowed a modern micro with built in ADC and EEprom to read the
actual voltage and current and control the PWM more directly, and be
properly user configurable. I don't think anyone has done that
however.

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