Re: [EVDL] charging a 48V pack with a 36V charger?
>
> -----Original Message-----
> From: [email protected] [mailto:[email protected]] On
> Behalf Of Darin at- forkenswift.com
> Sent: Friday, October 12, 2007 12:53 PM
> To: [email protected]
> Subject: [EVDL] charging a 48V pack with a 36V charger?
>
>
> Project ForkenSwift currently has 2 chargers available for its 48V pack:
>
>
> - a 36V 20A taper charger with a manually set timer and an ammeter;
> - a 24V 5A taper charger with an automatic voltage-sensing shutoff timer
> (which sometimes doesn't shut off because the old batteries don't quite
> reach the programmed voltage threshold).
>
> I'd like to use the 20A 36V unit, mainly because it's faster. But the
> problem is that according to my extensive calculations, 48 can't be
> evenly
> divided by 36.
>
> I was thinking of splitting the car's pack into 24V strings, then adding
> as
> "placeholders" two old floodies (left over floor sweeper batts the
> forklift
> co. gave us) to make up temporary 36v strings that can be individually
> charged. These two same "placeholder" batteries will be repeatedly
> cooked
> whenever each half of the car's pack is charged. Will this approach
> negatively affect the "good" batteries?
>
> One potential effect I see is the charging current may taper down sooner
> because those placeholder batts will have more resistance than the four
> good
> batts. Is that a serious problem?
>
> Darin
Based on this, and your recent other question(s); I would seriously consider a 72v system.
--
Stay Charged!
Hump
I-5, Blossvale NY
_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev
>
> -----Original Message-----
> From: [email protected] [mailto:[email protected]] On
> Behalf Of Darin at- forkenswift.com
> Sent: Friday, October 12, 2007 12:53 PM
> To: [email protected]
> Subject: [EVDL] charging a 48V pack with a 36V charger?
>
>
> Project ForkenSwift currently has 2 chargers available for its 48V pack:
>
>
> - a 36V 20A taper charger with a manually set timer and an ammeter;
> - a 24V 5A taper charger with an automatic voltage-sensing shutoff timer
> (which sometimes doesn't shut off because the old batteries don't quite
> reach the programmed voltage threshold).
>
> I'd like to use the 20A 36V unit, mainly because it's faster. But the
> problem is that according to my extensive calculations, 48 can't be
> evenly
> divided by 36.
>
> I was thinking of splitting the car's pack into 24V strings, then adding
> as
> "placeholders" two old floodies (left over floor sweeper batts the
> forklift
> co. gave us) to make up temporary 36v strings that can be individually
> charged. These two same "placeholder" batteries will be repeatedly
> cooked
> whenever each half of the car's pack is charged. Will this approach
> negatively affect the "good" batteries?
>
> One potential effect I see is the charging current may taper down sooner
> because those placeholder batts will have more resistance than the four
> good
> batts. Is that a serious problem?
>
> Darin
Based on this, and your recent other question(s); I would seriously consider a 72v system.
--
Stay Charged!
Hump
I-5, Blossvale NY
_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev