Battrey charging for base station.

#345327

I have a 55ah AGM battery running my itty bitty radio and Palomar TX100. How much charger will I need when I finally do start to TX? Right now I have 1500mah wall wart, but it is dirty and makes noise on RX. How many volts and Amps should I charge at?

#345328

It kind of depends on how much you talk vs listen. If you're a casual CBer you can probably get by with running off the battery alone then plug in a battery maintainer when not in use. You just need to be careful not to over charge the battery which can drastically shorten the life of it.

#345329

Hello LocomtvBreth,
Welcome to the forum. Your little radio at the most is about 2.5 amps when transmitting but that old Palomar amplifier has some old style transistors in it so I would guess a good 15 amps for it. Like Sly said you could get by with what you have now and save up for a good 20 amp or larger power supply. I hope you aren't charging the battery inside your house, the gases when charging are explosive and smell awful.

3's

Greg

#345341

not to mention toxic and corrosive.

#345349

Get a new or used 25 amp power supply, incase you get a 225 or 250 2 pill. Please dont charge a battery in your house if you have kids? Toxic invisible gases & major fire hazzard.

#345352

Lots of radio operators have used batteries indoors, including myself long ago, its not a good idea, there are just too many dangers involved.
Any type of standard battery charger you attempt to use will introduce noise in the system, they aren't filtered for that application.
Look into a good quality power supply, I wouldn't advise a "switching" type, they can be used but they have there draw backs also. Also remember that advertised current ratings are "surge" and not continuous duty... in other words buy one thats about double of what you need.
Good luck and enjoy.

#345356

Its an agm battery, same as in an office computer battery backup. No gassing or leaking here, its in my garage anyhow.

#345378

It's still a Lead/Acid rechargeable battery, even though it doesn't vent like a standard car battery it still can vent vapor, especially if over charged.
Just using it for the radio would probably be okay, but any long keying with that amplifier is going to drain it quickly.
http://en.wikipedia.org/wiki/VRLA_battery

Deleted User 14541 · #345379

I'd look for the manufacturers specs for charge rate and if you cant find them I'd stay under 1 amp. Thinking about this long term could get expensive if you don't have a surplus of these batteries and duty cycle and performance will never be up to snuff. Finding a charger that doesn't produce noise or modifying one might be a headache too. A good power supply is an investment for a radio operator.

'Doc · #347135

If those batteries are used in an office, how do they charge them there? There are different change rates for different types of batteries, so using the change rate for that AGM battery is a very good idea. They typically tale slightly more voltage than a wet cell battery, but not a huge amount.
How long will your 55 aH battery last? Divide the amount of average current use by the radio into that 55 aH. The result will be in hours. That assumes that the thing is fully charged, which they al;most never are, so it's a 'ball-park' time number. Typically, figure maybe half of that? If using the amplifier too, then add the currents for the radio and amplifier and divide it into that 55 aHs. That's close to what you can expect. If you use the fuse values for that time figuring it gives you a closer estimate than if you measure the currents drawn by either/both devices. Quit before you use up all of that 'time' or the battery ends up dead to the world.
- 'Doc

#347195

good questions

#356948

The amp hour rating on a battery can be confusing depending on the application.

You can "theoretically" get 55 "amp hours" out of a 55 amp hour battery. Eg: @ 1 amp for 55 hours, 55 amps for 1 hour etc. but that is only the amount of current it can produce.

The practical problem is what will the output voltage be at variable current draws. At a 5 amp draw a 12 volt 55 amp hour battery may provide 12-11.5 volts, at 10 amps it may only provide 10-9 volts. No easy answer and different battery types have different voltage to current curves.

Have to put a current and volt meter on the battery output (fully charged) and put the load on it and see what the voltage drop is to determine if it will be useful.

For surveillance purposes we figured to get the rated 12 volts volts for the longest time if only drawing 10% of the amp hour rating. Stuff would still work at the lower voltages past that, but it was time to finish the operation if reliability was critical.

A 55 amp hour battery should be fine with a CB & 100 watt amp for brief intermittent transmissions. I find those $12.00 trickle chargers work fine to keep a battery charged up when unattended.

#356952

I had a set up similar to this 10 years or so ago, I used an old converter/charger out of an abandoned camper trailer. It was quieter than the battery charger I tried before that. Wasn't perfect, but it worked.

#370127

my battery can sit outside and run some wires in. what about a solar charge unit? its all automatic.

#370129

Not to repeat what anyone else has said Batteries / charging them indoors which includes a garage is unhealthy. I bought a 36 amp 30 constant power supply from MaxxWatts. It is running a Galaxy 929 and a 2x 2879 pill amp on it and it hasn't shown any stress at all. For $60 plus $5 shipping no bad on the back pocket. They also have a 50 amp and a 30 amp all with adjustable voltage from 9 volts to 15 volt.

#381980

To prevent over charging hook a high watt light up in series with the charger.

#381982

when i was a kid(whoa), i used a regular big battery charger with a boost on a regular car battery.
when i wanted "full power", (which i can only guess what that equated to),
i would turn it on , haha, really put the ping in it.
yes it put a hum in the humdinger...
that radio was built like a tank. so i would say it depends on your radio.
as for fumes, well the kerosene lamp didnt do me in and i was conscience of the fact i was producing an explosive gas.
dont worry, it would have only been a small explosion

#384718

BOOM!
Small explosions are relative. If you're real close, they don't seem so small. This thread is really something. Lots of good information and I'm hoping someone can give me a little more.

Got a friend who just set up a nice mobile home at a yard where he can keep an eye on things 24/7. I offered to get a base station set up for him and was shocked to find he was running everything off the batteries in a Freightliner tractor and firing it up a few times a day to charge the batteries. I got a permanent 240/120V A/C service run to him but found the trailer was a little screwed up when he got it. All the heavy draw stuff runs off the A/C but the low draw stuff (lights, fridge, small fans etc.) is all on 12VDC (typical for RV's). He called me to say his lights and fridge and etc. all went out and the batteries died a day after I got the A/C hooked up but he could hear the fan in the rectifier (big 12V power supply) running so he was sure it was working. When I showed up, he had a big battery charger and 4 batteries sitting on the floor and had jumpers into the 12V circuits. I determined the power supply wasn't working at all but the fan would come on when he hooked the batteries into the system.

Long story short, the big 12V power supply isn't working. Although I dont' have technical info on it (other than it's a 120V A/C to 12V DC 50 amp output unit), I'm wondering if it's worth repairing. I know the small ones are basically throw away. This one is big and fits perfectly in between a transfer switch and fuse box with pre-cut wires coming in and out all bunched up under come cabinets so retrofitting anything different would be difficult but not impossible. So I"m wondering if anyone has experience repairing these bigger power supplies.

Any recommendations or advice would be very helpful. Maybe I'll just sell him my Radio Shack base and plug it into the wall ... he'll just have to use ice and a flashlight for the other stuff.

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