APC RS 900 charger

[ka3ebe_apc]

This was originally posted on APC forums on 12/22/2013

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Dose a APC RS 900 have a built in battery charger ? do all the APC back-ups have a built in charger

[ka3ebe_apc]

This was originally posted on APC forums on 12/24/2013

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Thank you for your fast replay, Have you ever heard of anyone using a sealed acid battery to replace the battery that is in the APC. I have two APC's, both with bad batteries and access to many small 12 volt wet cell batteries. I would like to attempt to wire both APC's to one 12 volt battery. I have looked at the APC wiring connections and it appears that one could make a harness to supply 12 volts to multiple backs. using the charger from just one of the units. I know that I will have to station the battery outside of the backup case, but the battery is small and sealed, I also believe I can extend the harness so the battery can be remotely placed. I would appreciate and thoughts you may have on this idea. I have been a general class amateur radio operator  for over 30 years so this is not the first time I have  tried to work outside the box with both successes and failures. I enjoy the challenge and it help keeps my 72 year old mind active. If you would like give me your input?   

[voidstar_apc]

This was originally posted on APC forums on 12/25/2013

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ka3ebe wrote:
Thank you for your fast replay, Have you ever heard of anyone using a sealed acid battery to replace the battery that is in the APC.

Yes. APC sells replacement battery modules which contain sealed lead acid batteries. Your UPS accepts an RBC32 replacement battery.

I have two APC's, both with bad batteries and access to many small 12 volt wet cell batteries. I would like to attempt to wire both APC's to one 12 volt battery. I have looked at the APC wiring connections and it appears that one could make a harness to supply 12 volts to multiple backs. using the charger from just one of the units. I know that I will have to station the battery outside of the backup case, but the battery is small and sealed, I also believe I can extend the harness so the battery can be remotely placed. I would appreciate and thoughts you may have on this idea.

APC doesn't support modifying the UPS. Some people do use their own batteries anyways, however you want to take this further and have your UPSes to share batteries. Some points to consider:

- The BackUPS are designed for a specific battery capacity. It may fail with larger capacity batteries. An example: one person here found without extra cooling his BackUPS couldn't run continuously for long enough to utilize the extra capacity.

- The inverter is the battery charger, so it could be tricky to disable charging.

- If you don't disable charging, you may run into issues with current sharing between chargers, and issues with performing a battery self-test.

Best of luck.

[ka3ebe_apc]

This was originally posted on APC forums on 12/25/2013

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The inverter is the battery charger, so it could be tricky to disable charging? I was unaware of this point, I have been unable to find a schematic for the RS 900. perhaps I may change and use lower capacity batteries, Perhaps not try to share one battery for multiple APC. Charging the batteries independently with some small charger I have would no problem, However to uncouple the battery charging from the inverter side could be very tricky, Thank you for you input you have opened a whole new line of thought for me.

Happy Holidays and a wonderful New Year

Casey   

[ka3ebe_apc · Accepted solution]

This was originally posted on APC forums on 12/22/2013

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Dose a APC RS 900 have a built in battery charger ? do all the APC back-ups have a built in charger