Battery Charging Currents of Assorted HP-Calcs & Peripherals

[Dieter]

(02-12-2016 08:52 AM)Sadsilence Wrote:  By system (when battery voltage goes high during charge time) all charging currents in HP calculators and peripherals decreases to the end of a charging cycle.

In general I agree – especially if the charging circuit essentially consists of a simple resistor. ;-) But are you sure this also applies to the 82120A battery pack? It contains a PCB that is described here: There is a 78L12 voltage regulator and a resistor which should provide a (nearly) constant charging current. But I'm not at all an expert in electronics, so you or someone else may be able to say more about how constant the resulting charging current will be with this design. Please note the linked PDF at the bottom of the mentioned URL, here the last page says 16 mA.

On the other hand discussing about 1 mA more or less does not make much sense assuming components with ±5% or even ±10% tolerance... #-)

(02-12-2016 08:52 AM)Sadsilence Wrote:  So 16mA at start is right and 14 mA at end is right, too ;-).

Fine. So let's make it 15 mA on average. ;-)

Dieter