Re: (ET) Update my my old "cooked" Trojan batteries

["David Barden" <daveb drizzle com>]

aha!  thanks for clearing up a heretofore abiding mystery!!  all this
time I thought my pack might be defective or undercharged by previous
owner...   very glad to know that's not the case.  :^)
thanks
again,
ciao,
dave b

On Fri, August 28, 2009 12:11 pm, David
Roden wrote:
> On 28 Aug 2009 at 7:36, David Barden wrote:
> 
>> and what's the best indicator of a battery's state of charge 
specific
>> gravity or at rest voltage?
> 
> SG. 
Voltage is better than nothing, and we have to use it with valve
> regulate
batteries since we can't get to the electrolyte -- but it's a
> relatively
unreliable and inaccurate SOC measurement.
> 
>>
>>
my 2 yr old interstate pack have never registered an sg of greater that
>> 1.265 no matter how hard I charge them(lately that's 2.45v per
cell). 
>> Is this natural? 
> 
> That's
normal for a deep cycle battery.
> 
>> I've other packs that
when fully charge are at 1.300.  will different
>> brands of
batteries use different acid concentrations?
> 
> Yes.
>
>>
>> I guess the good side of that low sg is they won't die
of grid
>> corrosion!  ;^)
> 
> Exactly!  A battery
designed to have a relatively low full SG is called a
> "starved
electrolyte" or "acid starved" battery.  That strategy also helps
> prevent over-discharging the electrodes.  It's the secret for East Penn
gel
> batteries' long life even in EV use.  For those batteries, a 100%
discharge
> is really only about an 80% discharge for the electrodes.
> 
> The downside of a starved-electrolyte battery is that its
published capacity
>  (and to some extent its usable capacity) is lower.
> 
> 
> 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/
> = = = = = = = = = = = = = = = = = = = =
= = = = = = = = = = = = =
> 
> 
> 
> 
>
_______________________________________________
> Elec-trak mailing list
> Elec-trak cosmos phy tufts edu
>
https://cosmos.phy.tufts.edu/mailman/listinfo/elec-trak
>