Replacing clock battery, just want to make sure I understand this right..

[Malakie]

Hi,

Am replacing batteries on A2000's.   If I understand right, if I use a basic lithium 2032 coin cell battery holder, I need to use a diode to insure it does not charge.  Correct?    BUT if I use the same coin cell holder but use a rechargeable 2032 lithium battery, do NOT add the diode?

I am also reading something about adding a resistor?!   

[zipper]

Yes, a LIR2032 should work.

[Matt_H]

There's also these things which slot in directly. Tiny little board with the diode integrated so you can use off-the-shelf CR2032s from the drugstore.

[Malakie]

Yes, a LIR2032 should work.

And with this, no need for the diode correct?  Just want to be sure.  Because what I have is the two pin coin holder for the 2032.  Without the diode, it 'should' charge the LIR2032 or ML2032 (I have both), correct?

[Malakie]

There's also these things which slot in directly. Tiny little board with the diode integrated so you can use off-the-shelf CR2032s from the drugstore.

I have a couple two pin basic 2032 holders now and a couple diodes, I understand they do require the diode so they don't receive a charge right?   It is the LIR or ML2032 I intend on using so with these same battery holders, I just forgo the diode and nothing more is needed... just want to make sure being this is modding that came along after I was around.

[Pat the Cat]

Never done myself on A2000.

You might find this thread helps;-

https://forum.amiga.org/index.php?topic=50279.0

Most people fit the diode on the battery holder, which means only one pin soldered direct to the board. (Which is why you see pictures of battery holders with one end raised up).

A more demanding approach is to mod the tracks on the motherboard,

Are you sure you don't want to fit a lithium rechargeable coin cell?

[Malakie]

Never done myself on A2000.

You might find this thread helps;-

https://forum.amiga.org/index.php?topic=50279.0

Most people fit the diode on the battery holder, which means only one pin soldered direct to the board. (Which is why you see pictures of battery holders with one end raised up).

A more demanding approach is to mod the tracks on the motherboard,

Are you sure you don't want to fit a lithium rechargeable coin cell?

umm.. all my posts above said I was probably use the lithium rechargeable.


I was asking if the diode was only for the CR2032 lithium coin cell NON rechargeable..  I wanted to double check since none of this was around back when I was involved in Amiga.   I am assuming the diode only gets used with the non chargeable 2032 and with the rechargeable 2032 I do not need that or anything else.  Just a basic coin holder and it will be good to go.   Just verifying things because there are dozen different methods, ways and comments out there, all different in how to do this.  Including using resistors and other newer components, all without any real explanation on why to use them.


So, the basic question I posed above was:    Use diode with non rechargeable 2032's and DON'T use with rechargeable 2032's, correct?  And that's it, nothing else needed?

[Pat the Cat]

Affirmative.

This is why people have advised you to use a lithium rechargable rather than standard non-rechargable coin cell.

Because with a non-rechargable type, you need to fit a diode.

Fitting it in the right place is a different story. You want it to connect the +5 of the coin cell to the +V supply on the clock chip - AND NOWHERE ELSE.

Otherwise the systerm tries to draw current from the coin cell with no main power, which rapidly exhausts the battery.

A clue - if you fit it (diode) the wrong way around, the clock chip won't remember the time.

[Pat the Cat]

Am currently a little tipsy for reading schematics and giving a more informed opinion.

EDIT: Page 9 of

https://www.amigawiki.org/dnl/schematics/A2000_R6.pdf

R803 looks correct on a rev 6 A2000. Take out R803 Put the diode there, stripe away from the battery towards pin 18 of the clock chip.

That should work. Dunno how different rev 4 is, probably not much.

Do check connectivity with the clock chip, you might have damaged traces in the area. Hopefully none, or fixable if some.

[QuikSanz]

 Can't even sift thru this, diode is to make sure current only goes out and can't come back in. for recharge must put power back in = NO diode.

Chris

A resistor maybe helpful if there is a mismatch in charge rate, no info on this but couldn't be very high value resistor.

[klx300r]

If you have your Amiga online I found the best way to keep your time on track is to use an online time server at startup. Best part is not having to take apart your system in big box miggies to change the battery every few years

[QuikSanz]

I mounted mine behind the LED's on a small board with a cut up audio cable. slide cover back, slide in new coin cell, done.

[klx300r]

@ QuickSanz
that's nice but I don't have to take my monitor off my case or slide cover off, or go buy the battery to put onto MB then put things back again...I just turn on my Amiga and the time is always correct

[QuikSanz]

That is only available after launch of TCP/IP stack, I use that to update. This machine is actually right @ startup.

[mechy]

If memory serves the only problem using lir2032 is the capacity of the rechargeable coins in Mah is alot less.