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Discussion Starter #1
The local community college is doing a pickup conversion. They had to
pick up the batteries before the end of the fiscal year so they have
been sitting for about 3 months. I finally convinced them that they
needed to be charged so we hooked them up and charged them. I got to
thinking that since the ones who may be driving the pickup when it is
finished might not be gentle on the batteries for the first few
charges that they should be cycled a little before we install them in
the pickup. Hopefully they will have the batteries in by January. I
have a load bank of light bulbs I took over and did about a 25Ah
discharge on them and then recharged them. I have enough bulbs to do a
12A load. My question is, how deep should I discharge them for the
first few cycles and how many cycles should I put on them before they
get installed in the truck?

FWIW, there is a picture of the pickup at www.lceva.org and more
pictures at our ning archive at
http://www.lceva.org/ning_archive/lccevc.ning.com/photo2679.html?page=1

Thanks,

--
David D. Nelson
http://evalbum.com/1328

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Discussion Starter #2
Hello David,

The standard break in for the batteries is not more than 75 amp load and not
less than 80% SOC for at least 200 cycles for the batteries to reach it full
capacity.

I broke in my batteries and motor at the same time while the batteries are
in the EV. My daily driving destination was only 1.1 miles a day on a up
hill run in a residential area at a average speed of 15 mph. I held the
battery ampere between 40 to 75 amps and the motor ampere at 100 to 200 amps
until the brushes were set or curve to the commentator.

The AH usage was 4.0 for each cycle which was still above 90% SOC. The
charging time took about 10 minutes at 25 amps. The 25 amps is the C/10
rating of the battery or a 250 ampere hour battery / 10 = 25 amps.

My E-meter (Link-10) could not be set for 250 ah, so I had to set it for 260
ah hour. It took 417 cycles before it display 100% SOC.

Discharging the batteries down to 80% State of Charge (SOC) should take less
cycles.

Roland






----- Original Message -----
From: "David Nelson" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Friday, October 08, 2010 6:23 PM
Subject: [EVDL] Breaking in new T-105s


> The local community college is doing a pickup conversion. They had to
> pick up the batteries before the end of the fiscal year so they have
> been sitting for about 3 months. I finally convinced them that they
> needed to be charged so we hooked them up and charged them. I got to
> thinking that since the ones who may be driving the pickup when it is
> finished might not be gentle on the batteries for the first few
> charges that they should be cycled a little before we install them in
> the pickup. Hopefully they will have the batteries in by January. I
> have a load bank of light bulbs I took over and did about a 25Ah
> discharge on them and then recharged them. I have enough bulbs to do a
> 12A load. My question is, how deep should I discharge them for the
> first few cycles and how many cycles should I put on them before they
> get installed in the truck?
>
> FWIW, there is a picture of the pickup at www.lceva.org and more
> pictures at our ning archive at
> http://www.lceva.org/ning_archive/lccevc.ning.com/photo2679.html?page=1
>
> Thanks,
>
> --
> David D. Nelson
> http://evalbum.com/1328
>
> _______________________________________________
> | REPLYING: address your message to [email protected] only.
> | Multiple-address or CCed messages may be rejected.
> | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> | OTHER HELP: http://evdl.org/help/
> | OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
>

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Discussion Starter #3
On 8 Oct 2010 at 18:23, David Nelson wrote:

> They had to pick up the batteries before the end of the fiscal year so
> they have been sitting for about 3 months. I finally convinced them
> that they needed to be charged so we hooked them up and charged them.

This depends on the batteries and their initial SOC. Most AGM and gel
batteries, if stored fully charged in a cool dry area, can sit for several
months with very little self discharge.

Flooded batteries like yours need a little more babysitting, but ordinary
charging every few months is all that's really necessary. The good news is
that since they're open batteries rather that valve regulated and "sealed,"
you can monitor their SOC with a hydrometer.

> My question is, how deep should I discharge them for the first few
> cycles and how many cycles should I put on them before they get
> installed in the truck?

Unless the users plan to enter a range competition straight away after
finishing the conversion, I wouldn't cycle them at all right now. For most
normal uses, there should be ample time to exercise them after the EV's
final assembly is done. I don't see much reason to waste energy and use up
some of their cycle life if you don't need maximum range immediately.

David Roden - Akron, Ohio, USA
EVDL Administrator

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