Icom R-20 AA battery spacer question

[Nap]

Hi,

I have a question for you R-20 old hands. I'm looking at the scenario where the Li-Ion battery goes flat and I can buy some AA batteries but I don't have the AA battery spacer with me. So I inserted some batteries without the spacer to see what gives. I expected some rattle but that would be OK.

What happened is that everything looks fine, the batteries sit tight and make good contact but the R-20 won't turn on. I tried with the spacer and it works.

This quite puzzled me and on closer inspection I've noticed a small rubber push button at the bottom of the battery compartment. This button would be pressed by the Li-Ion pack but not by the AA spacer. So I believe it helps the R-20 decide which kind of batteries you're using.

However inserting the AA batteries without the spacer still don't push that button, indicating - correctly - that you're using AA not Lithium pack.

So I can't figure it out. There must be another trick that the spacer is doing when inserted.

Anyone knows how exactly the R-20 senses the spacer's presence?

Thanks,
Nap

 

[Essexscan]

I'l look at my r-20 and spacer tomorrow and see what I can find out

 

[mancow]

Take them out and look in the compartment. You will see a small button. The spacer depresses the button to tell the radio it's using AA batteries. You will need to fabricate something that will push that button.

 

[Nap]

It looks to me the other way round - the Lithium battery will push the button (it has a flat surface) but the AA spacer will not (it has a hole where the button is located). Puzzling stuff.

Nap.

 

[mancow]

That might be the answer. I have the spacer in front of me but the radio is not here right now so I can't look at the two to compare them.

 

[oregontreehugger]

Is it possible the Li-Ion battery depresses the button so the radio knows it's okay to charge the battery inside the radio? This would explain the "hole" for the alkaline spacer pack.

I can see why you wouldn't want the radio to try and charge the alkaline AA cells. Poof.

 

[Nap]

Well, there are different contacts sets for Lithium and AA. There's no physical way you could connect a Lithium battery to the AA contacts or the other way round. So it would be easy to not charge by mistake AAs just by making sure that the charger sends current just to the Lithium contacts but not to the AA ones.

Which raises the question of the utility of the button.

Baffled,
Nap

 

[mancow]

I figured it out.

Look at the bottom right corner. There is a square hole with two metal tabs. The plate has a piece that is inserted in there pushes on them which makes a connection. I tested it by making a small ball out of some paper and placed it in there. The battery pressed it into the hole and allowed the radio to come on.

 

[Nap]

Wow! Thanks! It works!

This could save my day when I need to use AAs and don't have the spacer with me....

I wonder why they chose to do that.... AA batteries fit nice and tight without any spacer....

Nap.

 

[Essexscan]

what i found is the Li-Ion battery pushes the switch in the center of the battery compartment, the plastic AA spacer has a space cut out on the bottom of it to not push the switch but the spacer doesn't connect the metal tabs together at the bottom right. It pushes the plastic tab between them down when you lock the spacer in place. there is a small tab on the spacer that pushes it down when in place

I guess the wanted a way to ensure AA would only be used in an emergency and couldn't be charged by accident damaging the R-20

 

[mancow]

Yes, you are correct. It has a small tab that goes in the hole where those two metal things are. Other than that the insert just acts as guide to keep the batteries in place.