Getting 922 battery worries

[cbandjerk]

sergei you just contradicted yourself.

You said a UPS will not retain the ID. Then you said that as long as you keep it
powered up it will retain it's ID.

Well that's what a UPS does. It keeps it powered up.

So which is it????????

 

[Greg Mueller]

The problem is that UPSs are only big batteries too, so if it has to work for very long it too can run down.

 

[sergei]

Like I said ...read the posting ...a UPS will only keep the receiver up for the length of its battery charge and that depends on the model you buy.

 

[cbandjerk]

Ok so I agree that the UPS is a big battery.

So has it been proven that as long as the receiver is powered up the ID
won't be lost, even if the lithium backup battery is dead?

 

[sergei]

Now I'm curious..you post at the beginning of this posting that you've worked with
electronics all my life ...so what did you do? This might help us explain things to you better, either in more or less detail.

Also I just saw you started a thread on Satform under 4DTV Doomed...WHY?

 

[cbandjerk]

I've worked on motorola 2-way radios most of my life. I am very aware of the way motorola does things. I agree that GI started this but they didn't need to replilcate it.


That's the way most species go extinct. They have flaws and don't reproduce.

So they are doomed.

 

[cbandjerk]

No one really answered my question.

Will the 922 retain it's ID with the power applied even with a dead battery?

 

[Lak7]

Will the 922 retain it's ID with the power applied even with a dead battery?

I believe so. Reason I believe this is there are warnings about doing a "Soft Reset" (unplugging) to fix receivers glitches.

 

[cbandjerk]

I guess no one really knows if running a ups will save the ID if the battery is dead.

 

[rv1pop]

I do not trust the consumer UPS' for anything I really can not afford to lose. The output is a modified square wave and may drop up to 20 cycles in a row.... 1/3 of a second, which can cause a sync problem on a lot of equipment --- VCRs and TIVOs and probably DVRs. Also the batteries will go bad - especially as they get overcharged.

 

[Hermitman]

I'll give you half an answer. I've done some experiments concerning the ID battery power on an old 920 I have. I found that when the unit is not plugged in, the battery is feeding voltage to the IC chip holding the ID number. However, when the unit is plugged in (wall or ups, as long as its 120 volts ac), there is 5 volts being feed to the IC chip. So, my guess is that if the 922 has a similar power circuit as the 920, then power will be fed to the IC chip as long as 120 volts ac is available to the unit. Maybe if someone has a broken 922 they can test this out for sure. Good Luck.

 

[sergei]

I do not trust the consumer UPS' for anything I really can not afford to lose. The output is a modified square wave and may drop up to 20 cycles in a row.... 1/3 of a second, which can cause a sync problem on a lot of equipment --- VCRs and TIVOs and probably DVRs. Also the batteries will go bad - especially as they get overcharged.

That was certainly a problem with older UPS's, but some of the newer models made by APC seem to have addressed this problem with better designs.

 

[cbandjerk]

rv1pop
Yes that's what I have. Apc UPS with step aproximate sine wave. These units were made for computer backup. Computer power supplies are switching supplies very
similar to the power supply in the 920 and 922. I don't see why it wouldn't work.

Hermitman
Thank you for some really good info. Can you tell me where you measured that
5v on the board? Do you know which chip is being powered? That must be some kind of dual voltage circuit. I know that the battery doesn't get 5v across it when the unit is powered up or it would explode. Maybe the battery is unloaded when
the unit is powered and will last a lot longer that way. Too much speculation here.
Wish we knew more about what we are dealing with here. Motorola never gives
up schematics unless they absolutely have to

 

[Hermitman]

I looked through the top grill of my 922 (I really don't want to tear it apart since its working well). Its a completely different design than the 920. The 920 has a seperate circuit board for the smartcard and battery power, with connecting wires to easily trace the voltages. It looks like the 922 has only one board and all the components, including the battery, are in totally different locations. Maybe the 922 repair shop can answer your question. Good luck.

 

[cbandjerk]

Hermitman please PM me. thanks