Has anyone tried using a computer UPS as a battery backup for GR300 repeaters? I was looking for a cheap way to backup 2 GR300's for between 30 and 60 minutes.
The other thing I need help with is deciding what size unit to go with (I think it's measured in milliamps)
Using a UPS battery backup for a repeater
Moderator: Queue Moderator
Wow that's quite a tall order for a computer UPS! I'm not familiar with that model of repeater but in order to run the RF deck, controller and whatever else it'll take a bit of power, especially for an hour. A "SOHO" UPS won't be adequate.
Assuming everything's 12 V something more substantial like a few deep cycle batteries (80 Ah or more each) hooked in parallel would work much better.
Assuming everything's 12 V something more substantial like a few deep cycle batteries (80 Ah or more each) hooked in parallel would work much better.
GR Battery Backup
Well I've tried the UPS thing and get about 10 minutes. Motorola sells a HLN9455A - This is the GR1225 repeater battery backup module. Its alittle expensive (129.00 List) however I have used 3 of these in my different GR500 and 300 units and they work really good. I got a large Gell battery and this unit will trickle charge the battery also.....
If that doesn't interest you Astron does sell a "battery" revert power supply that you could replace your main with. I prefer the motorola part due to I can stick it right inside of the repeater case.
Jeff
KB2ZTX
If that doesn't interest you Astron does sell a "battery" revert power supply that you could replace your main with. I prefer the motorola part due to I can stick it right inside of the repeater case.
Jeff
KB2ZTX
Should not be a problem getting 30 to 60 mins out of a UPS. You just need to size it right.
Measure the AC current on TX and on standby. Calculate your duty cycle (what percentage is TX and what percentage is RX).
Look at the UPS charts and buy a properly sized UPS.
Example, a 25 watt GR1225 will draw about 1 amp on TX (at 120 VAC) and about 0.1 amp on RX.
Say you are 50% duty cycle, so average is about 0.5 amp. This is about 60 watts (0.5 amp x 120 volts).
Went to APC web site and found the SUA750XL will provide 5 hours at 50 watts, 2 hrs 52 mins at 100 watts, 1 hr 24 mins at 200 watts, 51 mins at 300 watts.
So even at constant duty cycle, you will get almost 3 hours.
Having said all of that, I always prefer the battery revert kit and a standard Gel Cel (never use wet cells). It is more efficient. longer run times, simpler maintenance, easier to swap batteries in event of extended outage. Shall I go on?
Good luck.
Measure the AC current on TX and on standby. Calculate your duty cycle (what percentage is TX and what percentage is RX).
Look at the UPS charts and buy a properly sized UPS.
Example, a 25 watt GR1225 will draw about 1 amp on TX (at 120 VAC) and about 0.1 amp on RX.
Say you are 50% duty cycle, so average is about 0.5 amp. This is about 60 watts (0.5 amp x 120 volts).
Went to APC web site and found the SUA750XL will provide 5 hours at 50 watts, 2 hrs 52 mins at 100 watts, 1 hr 24 mins at 200 watts, 51 mins at 300 watts.
So even at constant duty cycle, you will get almost 3 hours.
Having said all of that, I always prefer the battery revert kit and a standard Gel Cel (never use wet cells). It is more efficient. longer run times, simpler maintenance, easier to swap batteries in event of extended outage. Shall I go on?
Good luck.
Also check with DuraComm, they make the later and replacement power supplies for Motorola used in the GR300.
That is the one with the fan control.
They have a good add on battery revert module at a very reasonable price.
http://www.duracomm.com
That is the one with the fan control.
They have a good add on battery revert module at a very reasonable price.
http://www.duracomm.com
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Quarterwave
- Posts: 68
- Joined: Mon Mar 03, 2003 7:15 pm
eerrr just wire 2 big truck batteries to the PS with a just-big-enough fuse inline. The batts stay charged and if the AC is off long enough to drain them the ps will blow the fuse with inrush current to the batts upon powerup but will still run the eq. You just have to jump your batteries. I have had this "easy" and dirty setup for 5 years, works great. You can get the batteries at a big truck dealer, there are alot of them that take a charge, hold charge and trickle out at 10-15 amps just fine but won't crank a starter, so they are considered "bad".
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Quarterwave
- Posts: 68
- Joined: Mon Mar 03, 2003 7:15 pm
Uh, no. I wouldn't do that.
It is on one of my repeaters, thats just used for personal stuff, it really doesn't need to be on back up, but I had the materials, so I did it. I have never had any trouble with it, it is fused well, and the batts ran the repeater and fans for 3 days one time when something else tripped a breaker. Public Service stuff here are on sites with generators. Except the city PD, they don't care, I guess. They don't even know how to use talk around if thiers goes out...the just use thier "cell phone". Idiots. I have built large DC systems with switching, chargers you name it, so I know there are many ways to do it.
It is on one of my repeaters, thats just used for personal stuff, it really doesn't need to be on back up, but I had the materials, so I did it. I have never had any trouble with it, it is fused well, and the batts ran the repeater and fans for 3 days one time when something else tripped a breaker. Public Service stuff here are on sites with generators. Except the city PD, they don't care, I guess. They don't even know how to use talk around if thiers goes out...the just use thier "cell phone". Idiots. I have built large DC systems with switching, chargers you name it, so I know there are many ways to do it.
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hamptonbeach
- Posts: 128
- Joined: Wed Jul 07, 2004 8:36 am
I use an APC1400 on my MSR2000 - not only are they good for short power outages, but they provide filtering against power spikes and boost in case of brownouts or low voltage.
You determine how large of a UPS you need, it will depend on the load and the amount of run-time you want.
APC has a load calculator on-line here:
http://www.apc.com/template/size/express/index.cfm
You determine how large of a UPS you need, it will depend on the load and the amount of run-time you want.
APC has a load calculator on-line here:
http://www.apc.com/template/size/express/index.cfm
I have a GR300 on a UPS and it gets 45-60 mins from the UPS - with about 90% of that time being standby. With that said, the major reason the UPS is there is for surge protection. I am sorry that the specs of the UPS escape me.
Then, once it dies, this takes over.
http://www.tessco.com/products/getProdu ... sku=443005
The Samlex battery backup module switches things over to the deep cycle marine battery. Has held this particular repeater for up to 2 days.
Jay
Then, once it dies, this takes over.
http://www.tessco.com/products/getProdu ... sku=443005
The Samlex battery backup module switches things over to the deep cycle marine battery. Has held this particular repeater for up to 2 days.
Jay
I can't remember who makes it but we have a nice little 12v switching power supply that has backup functions built in. It has a deep cycle battery connected to it and it will charge the battery as needed. When the AC power to the power supply fails, it switches to the battery with no interuption. It also has a little display that showes the voltage, current draw, and charging status. Pretty slick little device and makes backup power simple as pie.
"I'll eat you like a plate of bacon and eggs in the morning. "
- Some loser on rr.com
eBay at it's finest:
Me: "What exactly is a 900Mhz UHF CB?"
Them: "A very nice CB at 900Mhz speed!"
- Some loser on rr.com
eBay at it's finest:
Me: "What exactly is a 900Mhz UHF CB?"
Them: "A very nice CB at 900Mhz speed!"
Any DC source that is voltage regulated in the range of 13.4-13.8 VDC will not recharge a deep cycle battery. The reasons are complex and explained in (or by materials referenced in) the earlier thread to which I referred.
Note also that if a decent sized battery bank (say 200-400 AH) is depleted to, say, the 50% point, and then attached to a typical 20-40A power supply, the current drain of the batteries is likely to blow the output fuse or breaker on the power supply.
Finally, note that most "battery revert" circuits on the typical power supply end up with a so-called "trickle charge" on the batteries; that is to say, a charge that is current regulated in the range of 50-200 mA. Such a charge will kill the batteries very quickly, particularly gel cells, since it will allow voltage to rise to the 15+VDC range.
Note also that if a decent sized battery bank (say 200-400 AH) is depleted to, say, the 50% point, and then attached to a typical 20-40A power supply, the current drain of the batteries is likely to blow the output fuse or breaker on the power supply.
Finally, note that most "battery revert" circuits on the typical power supply end up with a so-called "trickle charge" on the batteries; that is to say, a charge that is current regulated in the range of 50-200 mA. Such a charge will kill the batteries very quickly, particularly gel cells, since it will allow voltage to rise to the 15+VDC range.
I disagree with RKG......a 12 volt battery is just that,and 1.8 volts above that WILL charge the battery.
If the 13.8 volt trickle charge is regulated at 50 to 100 mils of current,even a dead bank of batteries will not blow the output fuse or breaker,because the bank cannot draw more than the regulated 50 to 100 mils!
Also I don't feel that a 50 to 100 mill trickle will kill a battery.,and after 2 years you should replace that battery anyway.
mod
If the 13.8 volt trickle charge is regulated at 50 to 100 mils of current,even a dead bank of batteries will not blow the output fuse or breaker,because the bank cannot draw more than the regulated 50 to 100 mils!
Also I don't feel that a 50 to 100 mill trickle will kill a battery.,and after 2 years you should replace that battery anyway.
mod
I use the Optimas with no problem. They charge fully on only 13.8 and will not boil off. You can charge them through a 20 Ohm x 20 watt resistor to limit charge current.
For backup on that system, just use 12 volts. No UPS needed.
Get a deep cycle battery and a Tessco battery backup unit for about $60 (just a diode and a resistor in a box) and ties the battery into the GRs power supply as per included diagram.
IF you need to use a UPS for whatever reason, just connect a deep cycle or large gel battery to the UPS's battery leads and dump the original UPS battery. It will charge just fine. The large battery will run the UPS much longer then the OEM. Never seen one overheat, either. Just don't overload it.
I just did a 100W Mastr IIe with dual Optimas on the TR unit and PA. The GE voter runs on 20VDC (converted from 120AC), so I used a 350VA UPS to run only the voter's AC input. The UPS's battery leads were extended to the Optima's output leads. The batteries are both charged by a "smart charger" designed specifically for this purpose rather than using a charge resistor or adapter. The Mastr's backup system works great and will run for hours on the pair of yellow top Optimas. The original UPS battery now runs my antenna network analyzer so it didn't go to waste.
For backup on that system, just use 12 volts. No UPS needed.
Get a deep cycle battery and a Tessco battery backup unit for about $60 (just a diode and a resistor in a box) and ties the battery into the GRs power supply as per included diagram.
IF you need to use a UPS for whatever reason, just connect a deep cycle or large gel battery to the UPS's battery leads and dump the original UPS battery. It will charge just fine. The large battery will run the UPS much longer then the OEM. Never seen one overheat, either. Just don't overload it.
I just did a 100W Mastr IIe with dual Optimas on the TR unit and PA. The GE voter runs on 20VDC (converted from 120AC), so I used a 350VA UPS to run only the voter's AC input. The UPS's battery leads were extended to the Optima's output leads. The batteries are both charged by a "smart charger" designed specifically for this purpose rather than using a charge resistor or adapter. The Mastr's backup system works great and will run for hours on the pair of yellow top Optimas. The original UPS battery now runs my antenna network analyzer so it didn't go to waste.
1. Those who think that you can recharge a significant nick out of a deep cycle battery with a single-voltage voltage-regulated DC source need to do a bit more research on storage battery chemistry. In fact, the battery's internal resistance will cause the battery terminal voltage to rise to the equivalent of the charger voltage very early, and once the two are the same, no current will flow. In order to recharge a storage battery, you need to run it through initial charging stages slightly above (for flooded cells) or slightly below (for SLVR cells, such as gel cells, AGMs and Optimas) the gassing point.
2. Those who don't think that a current-regulated "trickle" charger doesn't kill batteries should talk to a guy who has a room filled with batteries killed by such a charger.
3. A storage battery, properly maintained, should last for the lesser of 500-750 deep (50% depleted) cycles or 10 years, whichever comes first. If the batteries are dead after two years, it is because they have been killed by a trickle charger.
4. An inexpensive solution for fdc's application would be:
One or two good 12V gel cells (such as West Marine sku 327025, which are East Penn 8G31DTs);
A 20A Statpower (West sku 333404) smart charger;
Appropriate wiring and fuses.
When the battery(ies) are charged and utility power is available, the Statpower will go into true float mode: it will carry any DC loads (up to 20A) and replace any shelf discharge in the batteries, but without trickling them.
When utility power is lost, the batteries will carry the radio. If the eqivalent constant load is under 18A, two 8G31DTs will carry that load for 10 hours before reaching the 50% depletion point.
When utility power is restored, the Statpower will properly recharge the batteries and carry the load.
The batteries should last at least 10 years. No maintenance is required and no operator action is required to cycle the system.
Total cost about $600.
2. Those who don't think that a current-regulated "trickle" charger doesn't kill batteries should talk to a guy who has a room filled with batteries killed by such a charger.
3. A storage battery, properly maintained, should last for the lesser of 500-750 deep (50% depleted) cycles or 10 years, whichever comes first. If the batteries are dead after two years, it is because they have been killed by a trickle charger.
4. An inexpensive solution for fdc's application would be:
One or two good 12V gel cells (such as West Marine sku 327025, which are East Penn 8G31DTs);
A 20A Statpower (West sku 333404) smart charger;
Appropriate wiring and fuses.
When the battery(ies) are charged and utility power is available, the Statpower will go into true float mode: it will carry any DC loads (up to 20A) and replace any shelf discharge in the batteries, but without trickling them.
When utility power is lost, the batteries will carry the radio. If the eqivalent constant load is under 18A, two 8G31DTs will carry that load for 10 hours before reaching the 50% depletion point.
When utility power is restored, the Statpower will properly recharge the batteries and carry the load.
The batteries should last at least 10 years. No maintenance is required and no operator action is required to cycle the system.
Total cost about $600.