Dual removable 1/2AA battery holder install

[reactorpwr]

First I would like to say thank you to everyone on the forum.  I have been checking out the forum a day or two as I am in the midst of refurbishing a S+ round top 3 CM double diamond deluxe for my father.  Lots of useful information on these forums.


The machine has error 12 (battery).  I have the clear/set chips amongst other eeproms and a true chip puller.  I wanted to convert the machine from solder in lithium batteries to removable lithium batteries.  Here is my food for thought million dollar question: has anyone ever thought about putting in 2 removable battery holders?  Thus you can put a new battery in while the old one is still installed and you won't have a loss of power. 


It may seem overkill.  Adding batteries in parallel doesn't affect voltage, just added amperage.  It wouldn't be for a permanent dual battery install, only for times of changing batteries.  The only other option I see is to get a lithium battery (solder in style with leads) and put alligator clips on it, achieve the same concept but removable.


Thanks in advance for your input.

[Stayouttadabunker]

I've never put lithium batteries on an S+ MPU - these use an alkaline cell battery.
I do not know what would happen if you used lithium batteries neither do I recall in any documentation whether or not if regular batteries are REQUIRED?

May I add that it's very well possible lithium batteries may not have been in existence at the time S+'s were manufactured?
I'd have to Google that....lol

However, I DO like your idea of using two batteries in parallel although it's not really needed.
An S+ is so easy to set up again after a battery change and it's kind of like you have a brand new car!

But yeah... get it, some guys don't like to lose their accounting data accumulated... 

I've had MPU's sitting on shelf for 20 years and when installed into a machine - they're retained the accounting data stored on the memory chip.
However, even with that said, I've also had a few batteries under 2.85 Vdc after only 6-8 months with the machine being on 4/7....so that doesn't make much sense does it?

[therockinelvis]

I use a 3.6 vdc "AA" battery with a single "AA" holder with long leads. Solder to board and have battery on outside of the tray. Change battery with machine on. Do it with my S2000's and Bally's too.

[reactorpwr]

I use a 3.6 vdc "AA" battery with a single "AA" holder with long leads. Solder to board and have battery on outside of the tray. Change battery with machine on. Do it with my S2000's and Bally's too.

This is an idea I didn't think about either.  would be ideal to leave unit powered up and swap the battery.

[reactorpwr]

I would also like to thank Mr. Jim of Midwest Slots for the fast response and sale of new reel strips.  Good pricing and quick shipping!

[Badbaud]

I've never put lithium batteries on an S+ MPU - these use an alkaline cell battery.
I do not know what would happen if you used lithium batteries neither do I recall in any documentation whether or not if regular batteries are REQUIRED?

May I add that it's very well possible lithium batteries may not have been in existence at the time S+'s were manufactured?
I'd have to Google that....lol

However, I DO like your idea of using two batteries in parallel although it's not really needed.
An S+ is so easy to set up again after a battery change and it's kind of like you have a brand new car!

But yeah... get it, some guys don't like to lose their accounting data accumulated... 

I've had MPU's sitting on shelf for 20 years and when installed into a machine - they're retained the accounting data stored on the memory chip.
However, even with that said, I've also had a few batteries under 2.85 Vdc after only 6-8 months with the machine being on 4/7....so that doesn't make much sense does it?

Putting two batteries in parallel without using steering diodes is a bad idea. When one battery has more voltage then the other it will feed unwanted current into the weak battery.
This drains the good battery voltage and causes it to overheat and punches unwanted current into the bad battery. Producing a "self eating watermelon effect" which kills both batteries before their time.

[reactorpwr]

Badbaud, I understand where you are coming from.  The differences of batteries will always be fighting and thus result in both having shorter than regular life.  I was more inclined in having two available slots to have a free spot always available for a battery to added and the old one removed, thus never losing the power to begin with.  It honestly wasn't meant to be running two batteries at once.

[Badbaud]

That would work but you should do some investigating on the resident RAM chip(s) and discover what the lowest voltage they can run at is without losing data integrity.
You should monitor the voltage directly at the RAM chip, not at the battery, and when the voltage drops within .5 volts of that low rating put a fresh battery into holder #2 and immediately remove the low
battery in holder #1.