DIY Electric Car Forums banner

1 - 4 of 4 Posts

·
Registered
Joined
·
70 Posts
Discussion Starter #1
My recent disaster with a failed Raptor has made me wonder about what Id do if stuck without help. The obvious solutions are to get towed or car -trailered home. But there might be another way. AC drive owners need not read further. Perhaps one could parallel up the cells to a lower voltage to allow direct connection In my case Ive got 46 cells of LFP & 12 off AGM so it can really be only halved to 72V or if one cells is left out to 48V. Then there is the problem of the enormous current at starting. Id make up a starting resistor out of some old fencing wire aimed at limiting starting current to say 200A, so need around 0.25 Ohms. This needs to be shorted out so need another contactor. Maybe use a starter motor contactor. In my case I have my old Jones SCR Chopper built 40 years ago that might be still useable. Ill get it out. What would other owners do? David sharpe
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.sjsu.edu/mailman/private/ev/attachments/20110124/494311ac/attachment.html
_______________________________________________
| 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
 

·
Registered
Joined
·
70 Posts
Discussion Starter #2
Hi Dave,

We (I)'ve been here before on the EVDL. One of the benefits of
keeping the clutch when converting. Just keep a good pair of jump
leads in the vehicle and if you suffer a failed controller, put the
vehicle in neutral, tap the pack at enough cells to give you 1500 RPM
or so and off you go. Might be a bit slow but it'll get you home (or
to help) eventually. Just watch the cell volt levels tho. You'll
have to swap the jump leads to the next lot of cells when the first
run out of juice.

Regards, Martin Winlow
Herts, UK
http://www.evalbum.com/2092
www.winlow.co.uk


David Sharpe wrote:

> My recent disaster with a failed Raptor has made me wonder about
> what Id do if stuck without help. The obvious solutions are to get
> towed or car -trailered home. But there might be another way. AC
> drive owners need not read further. Perhaps one could parallel up
> the cells to a lower voltage to allow direct connection In my case
> Ive got 46 cells of LFP & 12 off AGM so it can really be only halved
> to 72V or if one cells is left out to 48V. Then there is the problem
> of the enormous current at starting. Id make up a starting resistor
> out of some old fencing wire aimed at limiting starting current to
> say 200A, so need around 0.25 Ohms. This needs to be shorted out so
> need another contactor. Maybe use a starter motor contactor. In my
> case I have my old Jones SCR Chopper built 40 years ago that might
> be still useable. Ill get it out. What would other owners do? David
> sharpe
>





_______________________________________________
| 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
 

·
Registered
Joined
·
70 Posts
Discussion Starter #3
Hi David,

Yep, that is exactly how it was done
in the beginning (I mean 100 years ago
give or take ;)
You can search the archives with the term
"contactor controller" to see a long discussion
on this, including some info from drivers of
actual original EVs.

Regards,

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 David Sharpe
Sent: Monday, January 24, 2011 5:47 PM
To: Electric Vehicle Discussion List
Subject: [EVDL] Stranded by a blown controller?

My recent disaster with a failed Raptor has made me wonder about what Id
do if stuck without help. The obvious solutions are to get towed or car
-trailered home. But there might be another way. AC drive owners need
not read further. Perhaps one could parallel up the cells to a lower
voltage to allow direct connection In my case Ive got 46 cells of LFP &
12 off AGM so it can really be only halved to 72V or if one cells is
left out to 48V. Then there is the problem of the enormous current at
starting. Id make up a starting resistor out of some old fencing wire
aimed at limiting starting current to say 200A, so need around 0.25
Ohms. This needs to be shorted out so need another contactor. Maybe use
a starter motor contactor. In my case I have my old Jones SCR Chopper
built 40 years ago that might be still useable. Ill get it out. What
would other owners do? David sharpe
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
http://lists.sjsu.edu/mailman/private/ev/attachments/20110124/494311ac/a
ttachment.html
_______________________________________________
| 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
 

·
Registered
Joined
·
70 Posts
Discussion Starter #4
I tried the starter motor relay thing and don't recommend it! All six of those
buzzards in parallel would get too hot to touch.

I did have my controller die, and just wired around it. No drama, as I have a
sepex so overrevving was not a danger.




________________________________
From: David Sharpe <[email protected]>
To: Electric Vehicle Discussion List <[email protected]>
Sent: Mon, January 24, 2011 5:17:07 AM
Subject: [EVDL] Stranded by a blown controller?

My recent disaster with a failed Raptor has made me wonder about what Id do if
stuck without help. The obvious solutions are to get towed or car -trailered
home. But there might be another way. AC drive owners need not read further.
Perhaps one could parallel up the cells to a lower voltage to allow direct
connection In my case Ive got 46 cells of LFP & 12 off AGM so it can really be
only halved to 72V or if one cells is left out to 48V. Then there is the problem
of the enormous current at starting. Id make up a starting resistor out of some
old fencing wire aimed at limiting starting current to say 200A, so need around
0.25 Ohms. This needs to be shorted out so need another contactor. Maybe use a
starter motor contactor. In my case I have my old Jones SCR Chopper built 40
years ago that might be still useable. Ill get it out. What would other owners
do? David sharpe



-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.sjsu.edu/mailman/private/ev/attachments/20110124/04e85eed/attachment.html
_______________________________________________
| 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
 
1 - 4 of 4 Posts
Top