A4000T battery info

[darkcoder]

Hello

 the battery of my 4000T is not charged enough to make the clock function
when the power is switched off. Luckly, the lithium battery of the A4000T is
not dangerous as the NiCd in other Amiga models.
However, I would like a new battery. I noticed that the A4000T motherboard
has a connector called "battery" for (I guess) an external battery.
Which kind of external battery I need?
If I were able to purchase such battery, can I simpli plug it in, or should
I remove in any case the soldered original battery?

The Dark Coder

[billchase]

You can indeed plug a battery into the battery connector
pins on the motherboard.  I do not remember the pin
assignments, but it might be in the 4000T hardware manual.
There is not one specifc type of battery that I know of
that you must use, but here is a link to some possibilities.
Batteries at Radio Shack
Obviously the ones with cords might be appropiate.

When mine died, I removed the original battery and
soldered a coin holder from a 486 motherboard in its
place.  Now I can replace the battery with another coin
style battery.  It is not hard, but you have to
disassemble the computer to purse this solution.

C Snyder

[SilvrDrgn]

I hope you put a diode in there to prevent the charging current from getting to the coin battery??  Could cause the battery to leak or blow up if you didn't.

[NightShade737]

The coin battery would be a 3.3v Lithium, which are rechargable, so the current shouldn't cause a problem.

[Markus_Bieler]

The battery in the A4000T aren't rechargable. You can simply cut the battery from the pins and put one at the connector on the board labeled battery (or bat?)

[Castellen]

In actual fact, the A4000T can be factory fitted with either a lithium (non-rechargable) or Ni-Cad (rechargable) coin type battery.

Resistor R180B (1.2k) is fitted for a Ni-Cad, in order to supply charging current.


You can also use the external battery connector, CN180.
There is a series diode in circuit, so only non-rechargable batteries can be used.
I'd suggest using any 3.6V lithium/silver oxide battery.
Also you can use two standard sized batteries (AAA,AA,C,D) in series, which will give you 3V.  This is a cheap and simple soloution which works fine, I've been using it for 4-5 years now with no problems.

Pins on CN180 are:
1 - ground (-)
2 - no connect
3 - key (pin removed)
4 - +3.6V


The battery voltage input tolerances of the RP5C01 real time clock are fairly wide, enabling many different battery types to be used.

For more information and device datasheets, look at http://amiga.serveftp.net/RTCrepair.html

[A4kT]

DEFINITELY NOT rechargeable! Don't risk it.

The "battery" jumper pin doen't seem to do anything.
I simply cut the battery holders and soldered a couple of wires
to a coin-type lithium battery holder which I mounted
just under the A4000T front pop-off cover.
I use a Panasonic CR2032 3v.
Works well

[Markus_Bieler]

You can simple put a maxwell AT-style battery onto the battery connector and remove the soldered coin-battery.

I did it with my A4000T as the factory installed battery was empty after a half year. I got the tip from theformer C= service station. It even doesn't matter if 3.6v or 4.5

There a holders for simple Alkaline-batteries with the correct conector and a glue-pad on the back, so you can use cheap batteries and fix it a suitable place.

Markus

[iamaboringperson]

I replaced my lithium cell (and it is a cell, not a battery), by removing it (carefully), and then plugging an expensive battery to that small connector.


Simple!