Guys:
I think the problem may be the purity of the lead in the first instance.
Stationary batteries have a design life of 10 to 15 years now look up the
Enersys SBS series thin plate technology 15 years under ideal conditions,
Yuasa Endurance 10 Years

Automotive and general purpose batteries 5-7 years give them poor (hot
conditions) then they will not do the life. (made from recycled stationary
batteries the lead is not usually as pure) 

Self discharge is an issue and in that respect all lead batteries specify a
maximum recharge interval of 6 months.

Charge level is for traction / semi traction batteries moves the electrolyte
by generation of gas equalising (boost charging) (2.3 - 2.4 vpc) then revert
to float levels (2.25-2.27 vpc) this is the technique used in automotive
charging (14.5v) This is at the expense of electrolyte as sealed (AGM /
VRLA) are not able to be topped up due to sealed construction. Hence can
shorten their life.

Small cost effective batteries are Cyclon (Gates energy products) (7-10 year
life) good high temperature performance and very high short term current
(it's a coiled thin plate low capacity (5 - 25Ah) their self discharge rates
are very good as well. This may suit your application...


Data is from too many yrs in the standby power field DC and UPS where
automotive batteries are scorned as only suitable for starting and replace
them every three years. (Ups under 3KVA also) cheaper to replace than do the
fans, caps and batteries..........

Steve


-----Original Message-----
From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] On Behalf Of
David VanHorn
Sent: 21 August 2006 20:00
To: Microcontroller discussion list - Public.
Subject: Re: [EE] Battery (SLA) deep cycle damage offset by
immediatetricklecharge?

>
>
> Do you mean that the wait after discharge followed by a quick charge is
> better than a slow charge that starts immediately after discharge? I don't
> see that from the reading, could you explain how you came to that
> conclusion?


The best answer is an immediate fast charge.

If the choice is between immediate and slow, and delayed and fast, my gut
reaction is that delayed and fast would be better. High current activity
tends to clear up a few problems in rechargable batteries.  I don't have any
direct data on lead-acid in this regard though.

Sulfation is proportional to depth of discharge and time, plus or minus
battery quality issues.

This is an "odd corner" question, not one that gets much attention.
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