Mike,
This is very important experience data,
thanks for posting this!
Contrary to other claims (granted, for other Li-ion chemistry)
there is a need for balancing, if your experience shows that
one cell may take 20Ah to balance against another cell in
your pack...
55 miles at 250Wh/mi is 13750Wh.
On your 162V nom pack that means at least 85Ah
or at least 85% DoD.
That is indeed uncomfortably low,
especially if you are not sure that
your cells are balanced.
Cor van de Water
Director HW & Systems Architecture Group
Proxim Wireless Corporation http://www.proxim.com
Email: [email protected] Private: http://www.cvandewater.com
Skype: cor_van_de_water IM: [email protected]
Tel: +1 408 383 7626 VoIP: +31 20 3987567 FWD# 25925
Tel: +91 (040)23117400 x203 XoIP: +31877841130
-----Original Message-----
From: [email protected] [mailto:[email protected]] On
Behalf Of Mike Nickerson
Sent: Wednesday, February 16, 2011 11:04 AM
To: 'Electric Vehicle Discussion List'
Subject: Re: [EVDL] conversion reliability
I can charge at work, so I'm only using about 50% each way. I wouldn't
be comfortable with what it would do to the batteries round trip.
I drove 55 miles on the pack once. That was about 3-4 miles too many.
I couldn't hear the alarm buzzer from the miniBMS at highway speed so I
noticed the batteries were in distress when I got to my driveway. By
then 2 cells were at 0 volts. I charged them up right away, babied them
during a slow charge and kept close track of the temperature of the
cells. They seemed to recover OK, but I'm still watching them.
I also learned that my cells weren't as balanced as I previously
thought. I had a few other cells that were about 20% lower than the top
cells. That's when I went out and bought the top-up charger in my last
post. That charger does a really nice job of pointing out how low your
cells are. Kind of makes you gulp when it puts in 20Ah just after the
main charging cycle finishes. On a full cell, it measures less than 1Ah
it tried to put in.
I also have found recently that my front disk brakes are dragging.
Fixing that should help range a little. I'm using about 250 Wh/mile
right now.
I'm hoping to get it down to 200-225 Wh/mile when I'm done. With a
well-balanced pack and the car well adjusted, I think I may make 60
mile+ range, but I'm still glad I can charge at work. I also have a
much louder buzzer now, and the alarm circuit is now wired into the oil
pressure idiot light on the dash too.
That energy usage is on a commute that is a combination of highway
(about 55
mph) and a little stop-go traffic as I get into town. However, I've
been driving it for 18 years now, so I know where the speed limit
changes are and when the lights are likely to change. I coast a lot. I
routinely get 35 mpg on an ICE that is EPA rated for 27 mpg. That
definitely makes my range numbers on the high side for variable traffic
and other drivers.
Mike
-----Original Message-----
From: [email protected] [mailto:[email protected]] On
Behalf Of corbin dunn
Sent: Tuesday, February 15, 2011 5:31 PM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] conversion reliability
Hey Mike,
This is very important experience data,
thanks for posting this!
Contrary to other claims (granted, for other Li-ion chemistry)
there is a need for balancing, if your experience shows that
one cell may take 20Ah to balance against another cell in
your pack...
55 miles at 250Wh/mi is 13750Wh.
On your 162V nom pack that means at least 85Ah
or at least 85% DoD.
That is indeed uncomfortably low,
especially if you are not sure that
your cells are balanced.
Cor van de Water
Director HW & Systems Architecture Group
Proxim Wireless Corporation http://www.proxim.com
Email: [email protected] Private: http://www.cvandewater.com
Skype: cor_van_de_water IM: [email protected]
Tel: +1 408 383 7626 VoIP: +31 20 3987567 FWD# 25925
Tel: +91 (040)23117400 x203 XoIP: +31877841130
-----Original Message-----
From: [email protected] [mailto:[email protected]] On
Behalf Of Mike Nickerson
Sent: Wednesday, February 16, 2011 11:04 AM
To: 'Electric Vehicle Discussion List'
Subject: Re: [EVDL] conversion reliability
I can charge at work, so I'm only using about 50% each way. I wouldn't
be comfortable with what it would do to the batteries round trip.
I drove 55 miles on the pack once. That was about 3-4 miles too many.
I couldn't hear the alarm buzzer from the miniBMS at highway speed so I
noticed the batteries were in distress when I got to my driveway. By
then 2 cells were at 0 volts. I charged them up right away, babied them
during a slow charge and kept close track of the temperature of the
cells. They seemed to recover OK, but I'm still watching them.
I also learned that my cells weren't as balanced as I previously
thought. I had a few other cells that were about 20% lower than the top
cells. That's when I went out and bought the top-up charger in my last
post. That charger does a really nice job of pointing out how low your
cells are. Kind of makes you gulp when it puts in 20Ah just after the
main charging cycle finishes. On a full cell, it measures less than 1Ah
it tried to put in.
I also have found recently that my front disk brakes are dragging.
Fixing that should help range a little. I'm using about 250 Wh/mile
right now.
I'm hoping to get it down to 200-225 Wh/mile when I'm done. With a
well-balanced pack and the car well adjusted, I think I may make 60
mile+ range, but I'm still glad I can charge at work. I also have a
much louder buzzer now, and the alarm circuit is now wired into the oil
pressure idiot light on the dash too.
That energy usage is on a commute that is a combination of highway
(about 55
mph) and a little stop-go traffic as I get into town. However, I've
been driving it for 18 years now, so I know where the speed limit
changes are and when the lights are likely to change. I coast a lot. I
routinely get 35 mpg on an ICE that is EPA rated for 27 mpg. That
definitely makes my range numbers on the high side for variable traffic
and other drivers.
Mike
-----Original Message-----
From: [email protected] [mailto:[email protected]] On
Behalf Of corbin dunn
Sent: Tuesday, February 15, 2011 5:31 PM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] conversion reliability
Hey Mike,
Mike Nickerson wrote:
> I've had my Honda del Sol conversion about 6 months. I drove it very
> solidly every day for about 3 months before starting some re-wiring
> projects that have had it out of commission for the last 3 months.
> Those weren't driven by reliability problems so much as the new
> owner's desire to tinker 8^). I got a little over 2000 miles during 3
> months. My commute is 46 miles round-trip, so I'll put the miles on
> pretty quickly once I'm back on the road again. Should be within the
> next
couple of weeks.
I see you have 45 100ah TS cells. What is your SOC% after the 46 mile
round trip commute?
--corbin
_______________________________________________
| 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
_______________________________________________
| 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
_______________________________________________
| 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