Alkaline battery opinions wanted [RE-wrenches]

[Travis Creswell]

I was going to make the same list that Warren made but he beat me to it.
IMHO, these are pretty significant disadvantages and that any one of them
essentially disqualifies them use in Solar and Wind energy systems.  I
suppose if you have a year round hydro site then you could make the argument
that the low charge efficiency and high self discharge does not matter.

One correction I would like to respectively offer.  In "general" terms NiFe
and NiCd are about 2x's more energy dense then PB.  Factor in that they can
be discharged to essentially 0 % with little affect on cycle life and you
have a battery bank that's nearly 1/4 the weight when compared to PB of the
same energy.  Footprint (or volumetric displacement) would also be much
smaller but not the full 1/4 since lead is denser (right?) then nickel, iron
and cadmium.

Best,
Travis Creswell
Ozark Energy Services


-----Original Message-----
From: Warren Lauzon [mailto:windsun at wind-sun.com] 
Sent: Saturday, May 24, 2008 11:43 AM
To: RE-wrenches at topica.com
Subject: Re: Alkaline battery opinions wanted [RE-wrenches]


While it sounds good at first, you might ask why nobody in the US is making 
them if they are so good.

There are advantages to NiFe (Edison) batteries, but the disadvantages are 
many, especially for RE systems:

1. poor weight/size to power ratio - you need a lot larger bank to store the

same power
2. expensive to make
3. poor charge/discharge efficiency - as much as 40% loss - which means you 
need a lot more solar panel.
4. very high self discharge, hard to find any real (non-advertising) data, 
but appears to be around 4% per day.
5. widely varying voltage vs state of charge, which means a "12 volt" 
battery bank migh vary from 17 to 11 volts between full and half charge. 
Some equipent cannot handle that range.
6. One non-technical problem is that it seems almost impossible to find 
replacement cells should one go bad.

............................................................................
......................
Northern Arizona Wind & Sun - Electricity From The Sun
............................................................................
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----- Original Message ----- 
From: "Jay Peltz, Peltz Power" <jay at asis.com>
To: <RE-wrenches at topica.com>
Sent: Friday, May 23, 2008 8:27 PM
Subject: Re: Alkaline battery opinions wanted [RE-wrenches]


>
> Hi Bob,
>
> That was going to be my question.
>
> I have always been under the impression that without a truly  destroyed 
> cell, they will run forever, its the electrolyte that wears  out.
> So yes there is MX, but a different kind.
>
> In regards to the efficiency, yes NiFe are less efficient, but if  they 
> last forever, how does that factor in?
> And since they don't have a cold de-rating factor, then you don't  have to

> oversize for winter time.
> Also they are not damaged by hard usage, or
>
> There are lots of reasons to use the NiFe, and I for one would if I  could

> get good ones.
>
> jay
>
> peltz power
>
>
> 



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