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Discussion Starter #1
I've seen some indirect comments over the last few months that suggest that some of the EV heavy-hitters don't believe in leaving their vehicles unattended while charging.

Is this true? Exactly what do you consider "unattended"? Sitting in/with the car? Being in the next room? The same building? The same zip-code?

Given the time that it takes to charge current battery technologies, isn't it a bit unrealistic to expect the average driver to sit with their car for 6 hours while it "refuels"? Isn't our goal as EV hobbyists in promoting these vehicles to develop cars that are realistic to operate and maintain?

If you have a "smart" charger like a Zivan or a Brusa with a GFI, is it really still considered too risky to plug in, jump on commuter train and ride away for the day? I mean, I'm not saying it's ok to build a Bad Boy charger with a coffee pot timer and leave THAT unattended, but come on, what level of control and fail-safe is considered "safe"?

Rich A.
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Discussion Starter #2
Hello Richard,

My first charger, a factory custom built by Cable Form for a 180 volt
battery pack, which was a SCR type that I can adjust any voltage to a
maximum of 315 volts which can charge at 50 amps and can be adjust down to
less than 1 amp.

A regulator can be switch in which can hold it at a constant current while
the voltage climb to the maximum setting I set it. Them the ampere would
drop to about 1 percent of the AH rating of the battery and would stay
there. This is where I had to estimated when the timer would should down
the battery charger.

When you have a new set up, I would have to monitor the charging system on
how long I should set the timer, for different rates of battery discharge
and charging rates. I would normally monitor the charging instruments for
about a hour and from that info, could estimate when I was at end of charge.
I would then set my watch alarm to remind me to check the charger rates.

I am now using a PFC-50B which does the same thing as the old charger did,
except it weighs 100 lbs less and I can charge at 50 amps DC at 45 amps AC.
If I discharge and charge the battery pack at the same rate at the same
ambient temperature, than I can set it and forget it after I determined what
this rate should be by doing some test charging and monitoring first.

Roland


----- Original Message -----
From: "Richard Acuti" <[email protected]>
To: <[email protected]>
Sent: Friday, October 19, 2007 7:01 AM
Subject: [EVDL] Unattended charging


>
> I've seen some indirect comments over the last few months that suggest
> that some of the EV heavy-hitters don't believe in leaving their vehicles
> unattended while charging.
>
> Is this true? Exactly what do you consider "unattended"? Sitting in/with
> the car? Being in the next room? The same building? The same zip-code?
>
> Given the time that it takes to charge current battery technologies, isn't
> it a bit unrealistic to expect the average driver to sit with their car
> for 6 hours while it "refuels"? Isn't our goal as EV hobbyists in
> promoting these vehicles to develop cars that are realistic to operate and
> maintain?
>
> If you have a "smart" charger like a Zivan or a Brusa with a GFI, is it
> really still considered too risky to plug in, jump on commuter train and
> ride away for the day? I mean, I'm not saying it's ok to build a Bad Boy
> charger with a coffee pot timer and leave THAT unattended, but come on,
> what level of control and fail-safe is considered "safe"?
>
> Rich A.
> _________________________________________________________________
> Peek-a-boo FREE Tricks & Treats for You!
> http://www.reallivemoms.com?ocid=TXT_TAGHM&loc=us
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>

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Discussion Starter #3
From: Richard Acuti
> I've seen some indirect comments over the last few months that
> suggest that some of the EV heavy-hitters don't believe in leaving
> their vehicles unattended while charging.
> Is this true?

No, I certainly don't "baby sit" my car while it is charging. But, I also make sure I trust the charger to turn off.

If I'm running a home-made "bad boy" charger, or an el-cheapo commercial charger that has no automatic shutoff, then I worry about what will happen to my expensive battery pack if/when it mindlessly charges forever. So, I add an external timer or other automatic cutoff device. This can be as simple as a $20 Intermatic mechanical 12-hour timer. Or, something as elaborate as you feel in the mood for.

--
"Excellence does not require perfection." -- Henry James
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart-at-earthlink.net

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