Help needed with a UPS for my GPSDO
Hi, I managed to find two second hand UPS at a ham rally but neither had
a battery pack in it
One, an "APC backups-ups 400" works well with a single 12V 7Ah sealed
lead acid battery.
The other, an "APC SMART-UPS 600" seems to have space for two batteries.
I have found a manual for the "600" unit but it mentions nothing about
the number of batteries or if they should be connected in series or
parallel :-(
Has anyone any experience of these ??
Any help more than welcome.
Regards,
Dave
Every APC UPS I've seen connects the batteries in series up to 24V. Above
that, the battery voltage is either 24V or 48V depending on the model.
If you search for the UPS model number and "replacement battery" you'll
find a lot of third party vendors with pictures and often specs of the
battery.
On Mon, Jun 26, 2023, 12:14 PM Dave via time-nuts time-nuts@lists.febo.com
wrote:
Hi, I managed to find two second hand UPS at a ham rally but neither had
a battery pack in it
One, an "APC backups-ups 400" works well with a single 12V 7Ah sealed
lead acid battery.
The other, an "APC SMART-UPS 600" seems to have space for two batteries.
I have found a manual for the "600" unit but it mentions nothing about
the number of batteries or if they should be connected in series or
parallel :-(
Has anyone any experience of these ??
Any help more than welcome.
Regards,
Dave
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Looks like an RBC5 is good. 2 x 12V7Ah batteries in series.
On 26 Jun 2023, at 19:17, Dave via time-nuts time-nuts@lists.febo.com wrote:
Hi, I managed to find two second hand UPS at a ham rally but neither had a battery pack in it
One, an "APC backups-ups 400" works well with a single 12V 7Ah sealed lead acid battery.
The other, an "APC SMART-UPS 600" seems to have space for two batteries.
I have found a manual for the "600" unit but it mentions nothing about the number of batteries or if they should be connected in series or parallel :-(
Has anyone any experience of these ??
Any help more than welcome.
Regards,
Dave
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On Mon, Jun 26, 2023 at 11:17 AM Dave via time-nuts
time-nuts@lists.febo.com wrote:
Hi, I managed to find two second hand UPS at a ham rally but neither had
a battery pack in it
One, an "APC backups-ups 400" works well with a single 12V 7Ah sealed
lead acid battery.
The other, an "APC SMART-UPS 600" seems to have space for two batteries.
I have found a manual for the "600" unit but it mentions nothing about
the number of batteries or if they should be connected in series or
parallel :-(
Has anyone any experience of these ??
Any help more than welcome.
The APC website has a battery selector tool which should tell you what
the right battery model is for the particular UPS:
https://www.apc.com/shop/us/en/tools/replacement-battery-selector?showAll=true
which should be worth a try.
Cheers,
Tim
On Mon, 26 Jun 2023 at 19:23, Dave via time-nuts time-nuts@lists.febo.com
wrote:
Hi, I managed to find two second hand UPS at a ham rally but neither had
a battery pack in it
One, an "APC backups-ups 400" works well with a single 12V 7Ah sealed
lead acid battery.
The other, an "APC SMART-UPS 600" seems to have space for two batteries.
I have found a manual for the "600" unit but it mentions nothing about
the number of batteries or if they should be connected in series or
parallel :-(
Has anyone any experience of these ??
Any help more than welcome.
Regards,
Dave
These guys are extremely knowledgeable about UPSs.
https://secure.ups-trader.co.uk/
For the UK at least, their battery prices are next to impossible to beat.
I would have thought if a UPS has space for two batteries, they would be in
series to give 24 V. My APC 650 VA one does. But I would ask ups-trader.
I'm sure they would give you a quote for batteries, but unless you are in
the UK, I expect carriage would make them uneconomic.
Dave
I have two APC "SmartUPS" 1500 units. Each has two 6 volt gel cell
batteries connected in series. I buy replacement battery packs,
pre-wired with the series wire and mating connector on eBay.
Best wishes,
Larry McDavid W6FUB
Anaheim, California (SE of Los Angeles, near Disneyland)
On 6/26/2023 11:03 AM, Dave via time-nuts wrote:
Hi, I managed to find two second hand UPS at a ham rally but neither had
a battery pack in it
One, an "APC backups-ups 400" works well with a single 12V 7Ah sealed
lead acid battery.
The other, an "APC SMART-UPS 600" seems to have space for two batteries.
I have found a manual for the "600" unit but it mentions nothing about
the number of batteries or if they should be connected in series or
parallel :-(
Has anyone any experience of these ??
Any help more than welcome.
Regards,
Dave
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CORRECTION: the two gel cell batteries in my SmartUps 1500 VA units are
each 12 volt, for a total of 24 volt for the pack. Here is a link to a
listing for the replacement tow-battery pack with connector on eBay:
At least on the 1500 VA UPS, the battery pack connects with a large,
gray PowerPole connector. The smaller Model 600 UPS may use a smaller
connector.
The way APC orients the individual 12 volt batteries makes it difficult
to read the individual battery specifications.
Best wishes,
Larry McDavid W6FUB
Anaheim, California (SE of Los Angeles, near Disneyland)
On 6/26/2023 11:44 AM, Larry McDavid via time-nuts wrote:
I have two APC "SmartUPS" 1500 units. Each has two 6 volt gel cell
batteries connected in series. I buy replacement battery packs,
pre-wired with the series wire and mating connector on eBay.
Best wishes,
Larry McDavid W6FUB
Anaheim, California (SE of Los Angeles, near Disneyland)
On 6/26/2023 11:03 AM, Dave via time-nuts wrote:
Hi, I managed to find two second hand UPS at a ham rally but neither
had a battery pack in itOne, an "APC backups-ups 400" works well with a single 12V 7Ah sealed
lead acid battery.The other, an "APC SMART-UPS 600" seems to have space for two batteries.
I have found a manual for the "600" unit but it mentions nothing about
the number of batteries or if they should be connected in series or
parallel :-(Has anyone any experience of these ??
Any help more than welcome.
Regards,
Dave
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe send an email to time-nuts-leave@lists.febo.com
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe send an email to time-nuts-leave@lists.febo.com
Can I just interject, based on the subject line, that using a UPS
for a GPSDO is a bad idea ?
The UPS you have scored are designed to keep a 240W load running
for a few minutes and it is not very good at keeping a 10W load
runing for a long time, because most of the energy in the batteries
end up as heat in the UPS DC/AC converter.
According to the spec for the "APC backup-ups 400", holdover is
never going to be over 90 minutes, no matter how light the load.
Ditch the UPS, float-charge the same battery, and run your
GPSDO from that, possibly using a small DC/DC converter with a
wattage well-matched to the GPSDO consumption.
To take an example: A Trimble Thunderbolt uses 12W from cold, we
need to design for that, so a 15W DC/DC converter is prudent.
That will have an efficiency of around 80% at the 8W which the
Thunderbolt uses steady state.
That means that the DC/DC converter will draw 8W/.80 = 10W from
the battery.
That means that the exact same 12V/7Ah VRLA Lead-Acid battery will
keep your GPDSO running for at least 6-8 hours.
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
I would like to second Poul's suggestion here.
We use battery bank systems at all our communications facilities. With
the excellent efficiencies of both rectifier and DC/DC systems coupled
with excellent reliability for a rather minimal cost, simplicity of
maintenance/repair and easy customization, they are very hard to beat.
--
Sincerely,
Shawn Tayler
On Mon, 2023-06-26 at 20:41 +0000, Poul-Henning Kamp via time-nuts
wrote:
Can I just interject, based on the subject line, that using a UPS
for a GPSDO is a bad idea ?
The UPS you have scored are designed to keep a 240W load running
for a few minutes and it is not very good at keeping a 10W load
runing for a long time, because most of the energy in the batteries
end up as heat in the UPS DC/AC converter.
According to the spec for the "APC backup-ups 400", holdover is
never going to be over 90 minutes, no matter how light the load.
Ditch the UPS, float-charge the same battery, and run your
GPSDO from that, possibly using a small DC/DC converter with a
wattage well-matched to the GPSDO consumption.
To take an example: A Trimble Thunderbolt uses 12W from cold, we
need to design for that, so a 15W DC/DC converter is prudent.
That will have an efficiency of around 80% at the 8W which the
Thunderbolt uses steady state.
That means that the DC/DC converter will draw 8W/.80 = 10W from
the battery.
That means that the exact same 12V/7Ah VRLA Lead-Acid battery will
keep your GPDSO running for at least 6-8 hours.