Operating from battery

jazzboypro

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Hello all,

I would like to be able to operate my base transceiver from a battery in case the main power utility goes down (it does not happen often and usually not for too long). The radio is an IC-9700 that i would use on 2 meter FM for repeater work or simplex. For repeater work, i can hit most of the repeaters i use with 5 watts or less. I never worked simplex so i don't really know how much power would be needed. I would also like to be able to recharge the battery as fast as possible one the main power gets back. I would like to be able to operate from the battery for a few hours but not necessarily all at once. What are you guys using ? what would be the best type/brand of battery/charger to use ?

Many thanks
73
VA2FCS
 

mmckenna

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Do you currently have a 12 volt power supply for that radio?

If so, get one of these: Battery Backup Module, 25 Amps, For Use with any 12 or 24 Volt Power Supply
and get a 12 volt gel cell with enough ampere/hours to give you the run time you desire. The power supply will keep the battery charged when the power is on, and the battery will automatically take over when the power goes out.

If you don't currently have a 12 volt power supply for that radio, look for a 12 volt supply with "Battery Revert" or "Battery Backup" function.

If you wanna go full out, get one of these:
It has a small internal battery, but it also has provisions for an external battery.
 

prcguy

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A 100AH gell cell and a 60 to 100W solar panel can run some radios for a very long time. In the mid 80s I got a few 35AH gel cells and found it could power my Kenwood TS-430 for many nights of listening and some talking on HF, so you don't need a ton of AH for SSB use. FM will need more AH but for occasional use you would probably never run out of power.

In the US here we have Costco and other cheap warehouse type stores and a 100AH class battery is about $86 and solar panels and chargers are getting cheaper every day.
 

prcguy

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That's usually the big AC grid tie systems with a bunch of AC inverters on the roof. I've not come across any small 12v chargers that cause any noise or problems except if the radio is sensitive to fluctuation in the DC as the charger does its thing. My Elecraft KX3 radio with optional spectral display is sensitive to that but nothing else I've used.

Some solar panels can drive HF listeners/users of the 75/80 meter band crazy during daylight hours.
 

jazzboypro

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Do you currently have a 12 volt power supply for that radio?

If so, get one of these: Battery Backup Module, 25 Amps, For Use with any 12 or 24 Volt Power Supply
and get a 12 volt gel cell with enough ampere/hours to give you the run time you desire. The power supply will keep the battery charged when the power is on, and the battery will automatically take over when the power goes out.

If you don't currently have a 12 volt power supply for that radio, look for a 12 volt supply with "Battery Revert" or "Battery Backup" function.

If you wanna go full out, get one of these:
It has a small internal battery, but it also has provisions for an external battery.
I currently have 3 radios powered by an Astron RS35M but i'm only interested in operating my IC-9700 from the battery if need be. I've heard some talk about using lithium battery it seems to be the way to go but i don't really know.
 

prcguy

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Lithium Iron Phosphate is a really nice battery type that will give long life, but you have seen the prices. For under $100 a deep cycle gel cell will give you a good 5yrs of life and power your stuff just fine.


I currently have 3 radios powered by an Astron RS35M but i'm only interested in operating my IC-9700 from the battery if need be. I've heard some talk about using lithium battery it seems to be the way to go but i don't really know.
 

jazzboypro

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Lithium Iron Phosphate is a really nice battery type that will give long life, but you have seen the prices. For under $100 a deep cycle gel cell will give you a good 5yrs of life and power your stuff just fine.
Yep they are expensive. I almost pulled the trigger on one that was about 500$ below the normal price no charger included lol
 

mmckenna

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I currently have 3 radios powered by an Astron RS35M but i'm only interested in operating my IC-9700 from the battery if need be. I've heard some talk about using lithium battery it seems to be the way to go but i don't really know.
Yeah, lithium are nice if you can afford them.

However, gel cells work fine. I run a lot of -48vdc stuff at work, and all our sites use 600AH or larger plants made up of 24 each, 2 volt gel cells. These are "20 year" rated batteries (per the manufacturer). Pretty easy for me to drop $10,000 on one of them. I've been doing this for 24 years now, and the good gel-cells work fine -if- you treat them well. But then again, I've got space, budget, HVAC and the rectifier plants designed to deal with that stuff.
Usually the sites get upgraded every 10 - 15 years for one reason or another, so trying to extend the life of the system much beyond that doesn't make much financial sense. I could certainly make the argument for floor loading issues at some of the sites, but so far that's only been a challenge at one location, and we just moved it to a better site that didn't have that issue.
 

AM909

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... These are "20 year" rated [gel-cell] batteries (per the manufacturer).
Care to name the mfr/model? I'd love to have UPS batteries (2 x 6 V / 8 Ah?) that I don't have to remember to swap out before I discover they won't hold a charge. Like you, I end up replacing the UPS for one reason or another inside 20 years. :)
 

jazzboypro

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Yeah, lithium are nice if you can afford them.

However, gel cells work fine. I run a lot of -48vdc stuff at work, and all our sites use 600AH or larger plants made up of 24 each, 2 volt gel cells. These are "20 year" rated batteries (per the manufacturer). Pretty easy for me to drop $10,000 on one of them. I've been doing this for 24 years now, and the good gel-cells work fine -if- you treat them well. But then again, I've got space, budget, HVAC and the rectifier plants designed to deal with that stuff.
Usually the sites get upgraded every 10 - 15 years for one reason or another, so trying to extend the life of the system much beyond that doesn't make much financial sense. I could certainly make the argument for floor loading issues at some of the sites, but so far that's only been a challenge at one location, and we just moved it to a better site that didn't have that issue.
Any recommendation on a good gel cell for what i want to as stated in my original post ?
 

mmckenna

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Any recommendation on a good gel cell for what i want to as stated in my original post ?
I've used a lot of C&D Technologies TEL12-105 batteries at work. These are 100 amp/hour 12 volt gel cells. I'd often pass them down to local ham clubs, and they'd get many more years out of them after I was done with them.

But a 100a/h battery isn't light. Those were 90+ pounds each. You would probably want to carefully calculate your loads for the specific application and only buy what you need. Overbuying batteries is a waste of money if you never use the capacity. It's one thing for a high repeater site that may see frequent power outages, but keeping a single radio on in your shack won't require much. I have a few 35a/h batteries that I picked up from our fire alarm shop that I use. That's a manageable size. Still portable, but enough capacity for quite a bit of use.
 

merlin

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I currently have 3 radios powered by an Astron RS35M but i'm only interested in operating my IC-9700 from the battery if need be. I've heard some talk about using lithium battery it seems to be the way to go but i don't really know.
You can get 100 AH lithium batteries for a bit over$100 (US) Those are by far better than gel-cell, they last years longer than gel-cell. A couple lithium's should run your radios all day between charges.
A small 400 watt solar setup can charge the batteries in a few hours or faster charge with a 100 amp generator.
I have a small 85 amp SMPS that would charge such batteries with power restored in less than 2 hours.
Lithium's have their own charging curve so a charge module for those is very recommended.
The batteries range in price from $80 to over $400 so you have to shop around.
Amazon.com: Ampere Time 14.6V 20A, Intelligent AC-DC Battery Charger, Best Solution for 12 V Lithium Iron Phosphate, LiFePO4 Battery Recharging, Support Fast Charging : Automotive
 

prcguy

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Where can you get Lithium 100AH batts for that price? The cheapest I find are about 4X that. I have a couple of 100AH deep cycle batts about 10yrs old that still have good capacity. Not what they were new but they will power a 100W HF rig for a long time on a charge.

You can get 100 AH lithium batteries for a bit over$100 (US) Those are by far better than gel-cell, they last years longer than gel-cell. A couple lithium's should run your radios all day between charges.
A small 400 watt solar setup can charge the batteries in a few hours or faster charge with a 100 amp generator.
I have a small 85 amp SMPS that would charge such batteries with power restored in less than 2 hours.
Lithium's have their own charging curve so a charge module for those is very recommended.
The batteries range in price from $80 to over $400 so you have to shop around.
Amazon.com: Ampere Time 14.6V 20A, Intelligent AC-DC Battery Charger, Best Solution for 12 V Lithium Iron Phosphate, LiFePO4 Battery Recharging, Support Fast Charging : Automotive
 
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