[ausev] need advice on power management doo-hickey

[tomsmail at wtez.net]

Undersized DC-DC not fully charging, and, Aux battery protection? This
sounds like the perfect application for the solar panels with trickle
charger.  Assuming proper protection the circuit could always be on, and
they (panels) could work in conjunction with your DC converter when
ignition is "on".

Tom



being rediculousIt seems rather rediculous to


> On Tue, 2008-01-22 at 08:24 -0600, MLAB wrote:
>
>> Say there was a device that monitored current in the battery line and
>> when it saw that a small current had been flowing for a couple of hours
>> it would open a contactor and isolate the battery.  Normally, there
>> would be either no current flowing (battery disconnected) or
>> intermittent high current (vehicle in use), so it would recognize if
>> there was a steady leak.
>
> Some good suggestions here about how to fix this problem in a practical
> way.
>
> In a different sense though, (not in the sense of properly shutting down
> the DC/DC or leaving it powered only when the vehicle is plugged in), I
> think there's an idea for preventing damage to the pack. I think it's
> easier to base this on voltages than current patterns. This way you can
> use a "stateless inspection" design, not needing to maintain a memory
> buffer of recent usage.
>
> As a last line of defense, a proper battery management system should
> watch each battery, or each cell in a system where cell voltages are
> available, and when any one of them gets below their critical "dead"
> voltage or some chosen threshold above that, it should send a signal to
> open a contactor, and the battery pack should disconnect from all loads.
> This threshold could be different between driving and sitting -- when
> driving, you'd probably want it to shut off later, to get the most
> distance out of it as you creep home. Just a guess.
>
> I don't know of a battery management system that does this but maybe
> there are some. I do know of a few that are being developed; maybe this
> will be among their features... :o)
>
>   --chris
>
>
>>
>> Does anyone know of such a doo-hickey?
>>
>
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