Monorail Malfunction

[sailor23606]

I have a Monorail modle 7245. I must be into antiques. The battery on the motherboard has died and wont hold a setting in the CMOS. Does anyone know what the specs are on this batt. It is the original and I cant read anything on it. It amazed me the batt lasted so many years.
BTW I have a new computer with VISTA that wont run half the software but my Monorail with Win 95 runs great. Go figure.
Thanks

[Platypus]

Any chance of a picture?

A lot of machines of that era used a backup battery built into the Real Time Clock chip:



Some can be hard to source, and may be soldered in. If it's this type, I doubt it's worth bothering with. Some boards had adjacent terminals to attach an external 3V backup battery.

[NooNoo]

If you are feeling brave there is this mod

[sailor23606]

Thanks for the replys. To get a pictue I will have to take the whole thing apart. I just reassembled it cause I tend to loose parts and forget where the plugs go. The batt is a disk mounted on edge on the motherboard (not flat). It is held between two cymble like ears. Problem is it seems to be bonded/welded to the ears.
If I can pry the old on out can I use any 3 volt batt of the same physical size?
BTW I am guessing the object is the batt because it has a "B" on the board next to it and it looks like a flat batt.
I can still use the computer. I just tap tap tap on the 'del' key as I start it up and change the boot sequence from 'cd a c' to 'c a cd' but every time I turn it off I must dgo through the same sequence and I fear someday this won't work.
Reguards

[NooNoo]

If it's a disk (button) type battery, you would have to replace it with the same type.

The only reason to change the battery is to keep the date and the bios settings. Bios is pretty dumb... the only thing that will stop you being able to do it every time is if the keyboard input socket or circtuitry is broken

[sailor23606]

Describe type. Physical size? Volts? other?

[Platypus]

Size, voltage, chargeable or non-chargeable...

For example, rechargeable 3.6V ni-cad:

Or possibly what you have, non-chargeable 3V lithium:

You can't swap between the types.

If yours is like the second image, it's soldered into the board. If you try to hack or break it out, you risk damaging tracks on the board.

[sailor23606]

Great
It looks like the second 3V nonrechargeable. Could I cut it out with a dremmel and soder wires into a remote holder? Can I replace it with any 3V battery that I can mount in the case or are there other specifications I need to be aware of?
Besides the physical size why cant these battery types be interchanged?
You are a weath of knowledge
Thanks for taking the time

[sailor23606]

Or..... I could unsoder it and soder a new one in (boy am I quick or what LOL) Where might I find one of these batts with the soder ears attached?
If your from the land downunder do you go with thunder?
Dennis

[slgrieb]

I buy most of my replacement UPS and CMOS batteries from Battery Specialist. They can almost certainly fix you up, but I would call them rather than deal with the web site. I've bought from them for more than 8 years.

[Platypus]

Could I cut it out with a dremmel and soder wires into a remote holder? Can I replace it with any 3V battery that I can mount in the case or are there other specifications I need to be aware of?

You could do that. The main hazards of using a dremel tool are you might slip and cut tracks on the board or damage a nearby surface mount component, or metal dust from the cutting could get in somewhere & make a short circuit. If there is enough access, you may be able to nip through the legs with a pair of fine, sharp pointed wire cutters. The "right way" is to unsolder the existing one and solder in an exact replacement. But you can use a different type of non-chargeable battery that supplies 3V. I've used a pair of AA or AAA alkaline cells in a holder, and they work for their shelf life (years):

Suppliers like slgrieb's should also have 3V lithium button cells with flying leads:

Besides the physical size why cant these battery types be interchanged?

Chargeable & non-chargeable batteries shouldn't be interchanged. If you fit a rechargeable where a non rechargeable one was, there's nothing to charge the new battery, and it'll go flat after a while, as rechargeable batteries "self discharge". If you put a non-chargeable battery in place of a rechargeable, it will likely be damaged, as it's not designed to take a charge.

[Platypus]

If your from the land downunder do you go with thunder?

Only if you give me a Vegemite sandwich...

Also on the topic of down under:

Something about my home state, Victoria, just appeared on the front page of Break:

http://my.break.com/Content/view.aspx?ContentID=511366

[sailor23606]

The vidio was kool.
I will do the solder thing. Good options on the alternate battery case.
Always heard great things about you Aussies. Hope to visit someday.
Nice chatting with you.
Dennis