Why is one battery marked #1 on the Voyagers?

[damaltor]

Hi!

I noticed that on Voyager calculators on the backside, there is a diagram showing the three batteries so that the user knows how to insert them. The rightmost battery is marked #1.

As the old Voyagers had two plasic flaps, it is kinda hard to insert this battery first. Also, it should not matter which battery is put in first - so what did I miss, why is the battery marked #1?

Back side of the 11C:
http://www.hpmuseum.org/11cbk.jpg

Malte

[rprosperi]

(01-09-2016 11:08 PM)damaltor Wrote:  Hi!

I noticed that on Voyager calculators on the backside, there is a diagram showing the three batteries so that the user knows how to insert them. The rightmost battery is marked #1.

As the old Voyagers had two plasic flaps, it is kinda hard to insert this battery first. Also, it should not matter which battery is put in first - so what did I miss, why is the battery marked #1?

Back side of the 11C:
http://www.hpmuseum.org/11cbk.jpg

Malte

It is only a reference to unambiguously document one side; there is no specific user requirement related to this battery (e.g. insert first or last, etc.) Recall that the Voyagers came from the HP of old, which was an engineering company making tools for engineers, and no self-respecting product for engineers would come without such an indicator.

All prior calculator models used batteries such that either the polarity didn't matter (for HP-supplied batteries that only could be inserted the 'correct' way) or it was marked (e.g. the 41C battery holder).

[Dave Britten]

I haven't fiddled with the battery compartment in my 12C enough to know, but is there any increased risk (or any at all) of short circuiting the cells when inserting from the other side first?

[rprosperi]

(01-11-2016 01:05 AM)Dave Britten Wrote:  I haven't fiddled with the battery compartment in my 12C enough to know, but is there any increased risk (or any at all) of short circuiting the cells when inserting from the other side first?

On the rare occasions that you have to change Voyager batteries, you can insert them in any order, from any side, etc. with no concerns. Of course, be sure to put them in facing the correct way, but I frankly doubt even if you did this wrong if it would do any damage. Voyagers are totally solid. If only all other machines were this reliable.

[Peter Murphy]

I started a thread on this subject in 2012.

Among others, Randy Sloyer replied, with what might be the most accurate information on the subject.

Unless anyone can report having created a problem by ignoring the implication that batteries must be inserted in Voyagers in a particular order, I think that there is no problem.

The thread can be easily googled: the search string

< battery murphy site:hpmuseum.org >

does it.

[damaltor]

Here it is:
http://www.hpmuseum.org/cgi-sys/cgiwrap/...ead=228996

So that might be a fairly undefined reason - it still could be that it is just to mark a battery like rprosperi said. All battery changing/short circuit/mem loss reasons are invalid for me, as there used to be a plastc flap on #1 and #3 on early models (and a single flap on #3 on the later models), so the only defined thing is that the middle battery will be put in last.

[jebem]

To replace the three battery cells on the original Voyager HP calculators while minimizing the risk of memory loss, the job should done as swift a possible, despite the fact that memory retention on this electronics is huge and there is no need to hurry.
To be fast it must be easy too.

On original Voyagers there is a #1 marked in one of the batteries in the information label.
Also these initial machines didn't use the spring coil contact or plastic retainers as the later series. Check it here.

This is the procedure I use to replace the batteries on one of my 1982 HP-15C Voyager calculators:

While holding the machine on your hand at a 45 degrees inclination and having the battery compartment in the upper position:




Drop the first battery cell in lowest position (#1):



Drop the second battery cell in the middle position:



Drop the the third and last battery cell on top.
Job done.



If you are not able to insert the third battery, check the batteries polarity orientation.
The negative side (smaller area) must be facing down.
In this example I tried to insert the three cells with the wrong orientation. They don't fit:

[jonese]

As I was cleaning my newly acquired 11C today, I think I may have stumbled on another potential reason to insert the rightmost battery first (marked #1).

If you've seen the inside of some earlier units, you'll notice that the rightmost connector (the negative terminal) is actually a thin protruding extension of the circuit board covered with a conductive trace on the edge where it touches the battery.

I wonder if HP thought there could be possible damage to the conductor or worse the board if the battery were slid in sideways. Placing this batter in first, would avoid this potential situation.

Just a thought.

[BobVA]

(12-06-2018 03:25 AM)jonese Wrote:  ...I wonder if HP thought there could be possible damage to the conductor or worse the board if the battery were slid in sideways....

Or perhaps, if the user had a static charge, that it was safer to discharge it (via the battery's metallic shell) to the ground side of the board rather than to the V-bat terminal, where it might cause damage or lock up?