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RE: [IP] RE:Batteries for the 722



Hi Robert,

 > MM states one must use Energizer batteries.
 > I thought they were crazy because what's the
 > difference.

There are two differences.

First, the discharge curve is specific to each kind of battery.
The pump has to know which battery you use, because it will show
(e.g., not real numbers) that your battery has 75% left when its
voltage drops to 1.489 Volt. That does not affect pump functioning
itself, just the low battery warnings and the battery status
indicator.

Second, good batteries allow high peak-discharge current. Every
time the motor in your pump advances the plunger, it draws a
current that is fairly high for a system running on a single AAA.
Cheap batteries will not be able to provide this current, or when
they do, their voltage may drop to a level that the pump considers
as "battery empty".

Given battery prices and average battery life, I would recommend
sticking with Energizer Max. (Rayovac Maximum Plus -- _not_
"Industrial Plus"! -- also worked for me; I discharged two of each
brand through a lab data recorder into a known resistance, and the
discharge curves are close enough for me. Voltage drop at peak
current was _better_ in the two Rayovacs than in the two Emax.)

Cheers,
Felix.
.
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