Re: (ET) AGM, Nicad,NiMH, & regular lead acid golf cart batteries

["David Roden" <etpost drmm net>]

On 16 Sep 2006 at 21:56, MakingLightning wrote:

> How come I never hear people talk about using AGM (absorbed glass mat)
> batteries?

AGM batteries excel at high current, but the ET doesn't need that much.  

The lack of maintenance is nice, but it comes at a high price.  AGMs cost 
per hour of actual use is typically 3-4 times as high as golf car 
batteries. 
 They also require a much more sophisticated charger than the standard ET 
charger, further increasing the cost of adoption.

I use gel batteries mostly because I have a bunch of them on hand.  
However, 
the ET was built for golf car batteries, and there is really no need to 
use 
anything else.

One ETer I know uses Saft STM5-180 nicads, again because he had some on 
hand.  These have a weight advantage for road EVs, but lower weight is a 
DISadvantage in the ET.  Saft STM nicads are very expensive.  On the plus 
side, nicads excel at cold weather performance and unlike lead batteries 
can 
be left uncharged indefinitely without harm.  Again, a more sophisticated 
charger is pretty much a requirement for Safts.

Christopher Zach uses aircraft nicads.  I'll let him comment on those.  

NiMH batteries in sizes appropriate to the ET would be crushingly 
expensive. 
 A few years ago an Ovonics 12 volt, 85 amp hour battery cost $2,200.00.  
You'd need at least 3 and probably 6. Do the math.  ;-)


David Roden - Akron, Ohio, USA

= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = 
Note: mail sent to the "etpost" address will not reach me.  To send 
me a private message, please use the address shown at the bottom
of this page : http://www.evdl.org/help/
= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
     And what rough beast, its hour come round at last, 
     slouches toward Bethlehem to be born? 

                                  -- W B Yeats

= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =