Battery Backup

[Spiffy50]

Hey gang, I'm working on a 12V battery system for my home station.

What I would like is to have all my 12V equipment running into a battery, then a power supply connected to said battery. The idea being, my gear would run off of the power supply as long as there is AC power. If AC power fails, the equipment will start draining the battery. Upon return of AC power, the power supply would charge the battery. The battery would also "suck up" any additional load that is over the amperage rating of the power supply.

Is this something that is fairly easy to do?

[Bill_G]

If you do it that way, make sure your homeowners insurance is paid first. (big grin)

You are describing a primary battery power system, not a battery backup. The battery pile is sized to give you full load for X number of hours upon AC fail. The battery charger is sized to overcome standby current to the load, plus fully charged maintenance current to the pile. Advanced chargers will also deliver sufficient current to overcome full load demands. They will also deliver enough current to charge a fully discharged pile while supplying full load current.

In your concept, you need to insert a battery monitoring current limiting device between the power supply and pile to prevent overcharging, and the eventual release of explosive gases, or a catastrophic breakdown of the batteries.

[Jim202]

If you do it that way, make sure your homeowners insurance is paid first. (big grin)

You are describing a primary battery power system, not a battery backup. The battery pile is sized to give you full load for X number of hours upon AC fail. The battery charger is sized to overcome standby current to the load, plus fully charged maintenance current to the pile. Advanced chargers will also deliver sufficient current to overcome full load demands. They will also deliver enough current to charge a fully discharged pile while supplying full load current.

In your concept, you need to insert a battery monitoring current limiting device between the power supply and pile to prevent overcharging, and the eventual release of explosive gases, or a catastrophic breakdown of the batteries.

As Bill has stated, it is very important to have a current limited power supply feed to charge the battery bank. The need to do this is to limit the charge current so as not to boil the batteries if they are wet cells like an auto battery. It is even more important if the battery bank is a gell cell or some varient of them.

A high rate charge heats up batteries even if they are not a wet cell type. Heat causes all sorts of problems if it gets too high. Most batteries have some sort of max charge rate and you need to keep below this point. On a home system, your not going to be concerned on how long it takes to bring the battery bank back up to full charge. Even if it takes 2 or 3 days, your better off than over heating the battery during charging.

The max voltage a battery can withstand is important also. The wet cell auto battery has a high voltage limit where if you exceed this, your going to boil the water out of it. This causes gas to develop that can cause an explosion if the right concentration collects. You need to provide for a vent to the outside of the building using the wet cell. Using other types of a battery bank can have the same out gassing. You need to follow the directions that go with the batteries.

The use of large size wire will cut down on voltage drop in your DC power system. Don't forget to carry this through to the battery charger power supply. Use of some sort of anti oxident compound on the connections will help keep the corrosion down.

Jim

[fineshot1]

Hey gang, I'm working on a 12V battery system for my home station.

What I would like is to have all my 12V equipment running into a battery, then a power supply connected to said battery. The idea being, my gear would run off of the power supply as long as there is AC power. If AC power fails, the equipment will start draining the battery. Upon return of AC power, the power supply would charge the battery. The battery would also "suck up" any additional load that is over the amperage rating of the power supply.

Is this something that is fairly easy to do?

I have a similar setup - I use the IOTA DLS55/IQ4 switching supply/intellicharger with two 75 amp hour AGM batteries
with the load all in parallel. This works well and when the power goes out all the radio gear stays powered up by the
batteries and when power is restored the batteries are topped back off by the IQ4. You could also choose a lower
rating supply/charger such as the DLS45 or 30, I just prefer the 55.

http://www.iotaengineering.com/dls55.htm

[Bill_G]

The Iota product looks good to me.

[Spiffy50]

Ooh! That's exactly what the doctor ordered! Wonder if there's a local supplier I can get one tomorrow from!

Many thanks for the input! And yes, I just renewed my policy in Feb :p

[fineshot1]

Ooh! That's exactly what the doctor ordered! Wonder if there's a local supplier I can get one tomorrow from!

Many thanks for the input! And yes, I just renewed my policy in Feb :p

I purchased mine on ebay when i still had a paypal account that worked, but after
they hosed up my account and could not fix it i gave up on ebay. Sometimes the
selling price on ebay is lower and sometimes it ain't. Its a gamble. Good Luck...

[RFguy]

Another good charger is the Xantrex Truecharge series. Either a Truecharge 10 or Truecharge 20.

Very good quality, low noise device.

http://www.xantrex.com/power-products/b ... rview.aspx

Just make sure that your power leads are propoer fused AT THE BATTERY.

[pforbes]

Ooh! That's exactly what the doctor ordered! Wonder if there's a local supplier I can get one tomorrow from!

Many thanks for the input! And yes, I just renewed my policy in Feb :p

I purchased mine on ebay when i still had a paypal account that worked, but after
they hosed up my account and could not fix it i gave up on ebay. Sometimes the
selling price on ebay is lower and sometimes it ain't. Its a gamble. Good Luck...

So, I'm not alone. eBay did the same to me and c/wouldn't fix it, so, bye, bye to them. PayPal fixed it in one phone call. Not eBay.

[pforbes]

You might want to check this out, too:
ICT22012-30BC

[Spiffy50]

Patrick, are you aware of any local sources for that ICT supply? Looks like it would work better for me than the previously mentioned ones.

[pforbes]

Not sure where you are, but we've been getting them from OminProvincial up here in the Toronto area. They are the best of all the hundreds of PSU's we've had.

[RFguy]

Patrick, are you aware of any local sources for that ICT supply?

ICT website has a distributor locator

http://www.ict-power.com/support/dist_search/

[Spiffy50]

Not sure where you are, but we've been getting them from OminProvincial up here in the Toronto area. They are the best of all the hundreds of PSU's we've had.

I'll give them a shout, they're certainly local to me. I'm in the city "above" yours, so to speak (hey, the signs say it!).

[Spiffy50]

Not sure where you are, but we've been getting them from OminProvincial up here in the Toronto area. They are the best of all the hundreds of PSU's we've had.

I'll give them a shout, they're certainly local to me. I'm in the city "above" yours, so to speak (hey, the signs say it!).

[pforbes]

Tell Jim Berger I sent you. Maybe he'll give you a better deal!