[NTLK] Interesting info on eMate battery discharge

[NewtonTalk]

Recently I had three eMates on my workbench that all had a battery pack
rebuild with 2450mAh Eneloop cells from the same manufacturing batch. I
measured the current drawn from their battery while they were switched off.

eMate 1: 1.2mA ... 2.1mA

eMate 2: 0.8mA ... 1.3mA

eMate 3: 2.2mA ... 3.2mA

These values were scientifically derived by staring mesmerized at my
voltmeter for five minutes per eMate while storing maximum and minimum
values in my brain. There might or might not be values that are lower or
higher than those shown above. I'd assume that the difference between the
three eMates is probably due to normal tolerances of their components'
current consumption.

One might think that this current consumption isn't all that much. After
all, eMate 3, on average, draws but 2,7mA from the battery. However, over a
day this adds up to about 65mAh. This will discharge modern Eneloop cells
within less than six weeks even if the eMate isn't used at all during that
time. With an original 1200mAh pack that has been used for more than two
decades, I guess all you'd get for standby time is a couple of days at most.

So don't worry if your eMate seems to discharge its battery fast. This, to a
certain degree, appears to be normal. If you can't ensure that your eMate
will be charged at least every couple of weeks, better remove the battery
and store it in the fridge.

Frank

-- Newton software and hardware at http://www.pda-soft.de