Battery choice: one string or two? [RE-wrenches]

[penobscotsolar at midmaine.com]

<x-flowed>
Allan,
  We have always favored one series string as opposed to any battery 
paralleling.Most any battery manufacturer would agree with this approach as 
"best case".  "Daisy chaining" even two series sets is going the way of 
T-105's being considered a great battery to use. We have more than 100 sets 
of KS series (17,21,25 & 30's) out there and have not had even one problem 
cell. Because of their height they are very space efficient (smaller battery 
box) and except for the KS-30's are easy to move with two guys. We buy the 2 
volt cells separately and are especially careful moving them around as they 
have no hard case around them, but they are easier to deal with overall, 
especially in many backwoods, off the grid systems.
  One adamant vote for a single series string........
Daryl DeJoy
Penobscot Solar Design 

 


Allan Sindelar writes: 

> Respected Wrenches, 
> 
> We have a good offgrid client who is replacing a 6-year old set of 20 golf
> carts (before our time) in an old 24V system, now upgraded with FX2024 and
> SB50. We have impressed upon him the value of industrial cells, fewer
> strings, etc. Our industrial battery of choice is the Rolls-Surrette because
> of their good reputation and our close relationship with Dankoff as a
> supplier (good support, free shipping etc.). 
> 
> The client is happy with the same overall capacity of 1100 amphours @ 20
> hour rate. We have narrowed down to two choices:
> The 4-KS-21PS, 1104 Ahrs, 2 cells/case & 267 lbs., 6 units, 24 3/4" height;
> one series string.
> The 6-CS-17PS, 546 Ahrs, 3 cells/case & 221 lbs., 8 units, 18 1/4" height;
> two series strings. 
> 
> Cost is close to the same for each choice. At under 300 lbs., both are heavy
> but maneuverable (into a basement). Both require that a new battery box be
> built. Both have the same 3/10 year warranty and projected cycle life. 
> 
> Which choice would you recommend, and why? I will share your responses with
> the client, who has already confirmed that they will abide by our resultant
> recommendation. (psst--I prefer one string, but would like other opinions,
> especially those who've been doin' it long enuf to see the results). 
> 
> Thanks for any contributions. 
> 
> Allan at Positive Energy 
> 
> - - - -
> To send a message: RE-wrenches at topica.com 
> 
> Archive of previous messages: http://www.topica.com/lists/RE-wrenches/ 
> 
> List rules & etiquette: http://www.mrsharkey.com/wrenches/etiquete.htm 
> 
> Check out participant bios: www.mrsharkey.com/wrenches/index.html 
> 
> Hosted by Home Power magazine 
> 
> Moderator: michael.welch at homepower.com
> 
> 
 

- - - -
To send a message: RE-wrenches at topica.com

Archive of previous messages: http://www.topica.com/lists/RE-wrenches/

List rules & etiquette: http://www.mrsharkey.com/wrenches/etiquete.htm

Check out participant bios: www.mrsharkey.com/wrenches/index.html

Hosted by Home Power magazine

Moderator: michael.welch at homepower.com
--^----------------------------------------------------------------
This email was sent to: michael.welch at homepower.com

EASY UNSUBSCRIBE click here: http://topica.com/u/?bz8Qcs.bz9JC9.bWljaGFl
Or send an email to: RE-wrenches-unsubscribe at topica.com

TOPICA - Start your own email discussion group. FREE!
http://www.topica.com/partner/tag02/create/index2.html
--^----------------------------------------------------------------


</x-flowed>