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[OM] Re: Quantum Turbo question

Subject: [OM] Re: Quantum Turbo question
From: Tim Hughes <timhughes@xxxxxxxx>
Date: Sat, 17 Feb 2007 01:45:08 -0800 (PST)
The lead acids using typical consumer chargers, do better with longer charge 
times to get the last
little bit into the battery. 

They recharge fairly fast to about 90% and then take a long time to get the 
last 10% in. If you
always short charge them, they will gradually "cycle down" and lose capacity 
and the cells will
also become unbalanced. The loss in capacity from incomplete charging 
eventually becomes permanent
even if you charge for a long time again (athough it will recover some).  

When the battery is new it has not been completely formed yet, and the first 
few cycles are
important for forming the plates and achieving long life and full capacity. As 
shipped capacity
may only be 70% of rated. The capacity actually continues to rise typically for 
about the first 25
cycles. So make sure to charge for 15-20hrs at least each time, in the first 
20cycles. The charge
cycle is often not quite normal in the first few cycles.  In general lead acids 
are almost always
undercharged by consumers. You are almost always better off leaving on charge 
for ~24hours rather
than till charge lights go out.  

You can design more aggresive smart chargers that far from shortening the 
battery life as is
common in fast NiMh chargers, actually improve lead acid battery life partly 
because the batteries
are no longer chronically undercharged,the cells get rebalanced properly each 
time and then at end
of charge the charger cuts back to a more benign float condition. 

To prove this for my work, I once rapid cycled some batteries identical to the 
ones used in the
quantum packs, to 1300 full discharge cycles before the plates began to fail 
and capacity dropped
radically. This is 3+ times better than the vendor claimed for the product 
under idealized slow
charge conditions. 

Always recharge for a few hours after use, even if you have only used them a 
bit.  Many,many more
shallow discharge cycles are possible than deep discharge cycles and you 
actually get more wh
extracted over life of battery before failure. Deep discharges are always 
tougher than shallow
discharges and complete recharge takes more than proportionately longer if 
deeply discharged. 

Tim Hughes

--- Walt Wayman <hiwayman@xxxxxxx> wrote:

> My brand-new Quantum Turbo has been charging since 3:00 a.m. -- I'm a night 
> owl -- and it's now
> nearly 11:30 a.m., and the yellow light that blinks while it's charging and 
> that is supposed to
> burn steady when it's fully charged is still blinking. The not particularly 
> elucidating manual
> says charging should take about four hours, but not to charge over 72 hours. 
> Seems like quite a
> range. Should I be concerned?
> 
> Walt
> 
> --
> "Anything more than 500 yards from 
> the car just isn't photogenic." -- 
> Edward Weston
> ==============================================
> List usage info:     http://www.zuikoholic.com
> List nannies:        olympusadmin@xxxxxxxxxx
> ==============================================
> 


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