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KD8IIS
12-26-2008, 05:01 PM
:DI thank everyone who replied to my last solar thread, much appreciated. After reviewing all the different types of options, I decided to go with the 45 watt Chicago Electirc Kit offered by Harbor Freight.

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=90599

I have 2 Deep cycle Marine battery. Do I wire them in series or in Parrallel? I'm assuming parallel since Ham radio requires 12 volts. (I use the Yaesu FT-450)

How long could I expect to transmit CW at 100 watts, and at 5 watts, with two fully charged (ran in parallel)?

I am new to solar energy and I know there are formulas to determine this, I haven't learned them yet. Nor would I trust my results if I did do the math without asking first. Any help would be greatly appreciated.

Can I leave the Batteries in my apartment to be recharged? Or should I build a little Milk Crate out back? I know the batteries produce Hydrogen, But is that only if the batt is overcharged; or does the hydrogen result as a normal prcess of recharging? I live in Ohio so we get lots of sub zero WX. Putting them outside might create

Does anyone else deal with Ice and Snow with their solar panels and how do you deal with that? Does it shorten the life of the panels?

Hypotheticly speaking, (I'm not going to do this!) could I use a 110 volt Battery charger hooked to a 350 watt Inverter, which is in turn hooked directly to the solar panels to regulate the charge on the batteries?

KI6RYC
12-26-2008, 06:42 PM
:DI thank everyone who replied to my last solar thread, much appreciated. After reviewing all the different types of options, I decided to go with the 45 watt Chicago Electirc Kit offered by Harbor Freight.

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=90599

I have 2 Deep cycle Marine battery. Do I wire them in series or in Parrallel? I'm assuming parallel since Ham radio requires 12 volts. (I use the Yaesu FT-450)

How long could I expect to transmit CW at 100 watts, and at 5 watts, with two fully charged (ran in parallel)?

I am new to solar energy and I know there are formulas to determine this, I haven't learned them yet. Nor would I trust my results if I did do the math without asking first. Any help would be greatly appreciated.

Can I leave the Batteries in my apartment to be recharged? Or should I build a little Milk Crate out back? I know the batteries produce Hydrogen, But is that only if the batt is overcharged; or does the hydrogen result as a normal prcess of recharging? I live in Ohio so we get lots of sub zero WX. Putting them outside might create

Does anyone else deal with Ice and Snow with their solar panels and how do you deal with that? Does it shorten the life of the panels?

Hypotheticly speaking, (I'm not going to do this!) could I use a 110 volt Battery charger hooked to a 350 watt Inverter, which is in turn hooked directly to the solar panels to regulate the charge on the batteries?

You don't provide enough information about your batteries to determine how long you can transmit at what power. To figure out how long your batteries will approximately last, there are some simple calculations you can use.

Find the battery spec sheet. For mine, 21H@5A 6.4H@15A 3.4H@25A. If you have the batteries in parallel, multiply the AH by the number of batteries.

Now, figure out your worst case draw. According to my FT-450, it will take a max of 22A @ 13.8V. That is 303 Watts. We can assume that is at 100W output, giving us an efficiency of 33%. So we now know with my battery, I can put out at worst case 100W for about 3.4 hours. For 5 watts, we take our efficiency(33%) and figure out the approx input power, 15W. 15W is ~1.2A so I could go QRP with my battery for 21 hours.

Keep in mind this is transmit time, not full time. You can use an ammeter or wattmeter inline to measure your receive current draw and do the similar calculations to see how long you can leave the radio on in receive mode.

Also, keep in mind that you do NOT want your batteries dropping below 10.5V or you will lose capacity and battery life. Your FT-450 has a built in volt meter that should be fairly accurate. I recommend mapping it to the "Voice/C.S." button and keeping an eye on the voltage, especially while transmitting.

As for charging the batteries, ALL lead acid batteries generate hydrogen and oxygen while charging. This said, most batteries are designed to recombine the gasses into water and go back into the cells under normal charging conditions. You should keep your batteries in a battery box for many reasons, hydrogen generation being just one of them. You can keep the batteries inside if you vent your box to the outside properly. It is highly recommended to use a battery charger meant for solar power. Using one will keep hydrogen generation to a minimum. There is a plethora of information out there on how to setup a solar system with batteries, just google for it.

A last note, I would include RF filters on my power leads from the battery to the radio/tuner in case any RF comes back and interferes with your battery charger or vice versa.

W6GQ
12-26-2008, 06:49 PM
:DI thank everyone who replied to my last solar thread, much appreciated. After reviewing all the different types of options, I decided to go with the 45 watt Chicago Electirc Kit offered by Harbor Freight.

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=90599

I have 2 Deep cycle Marine battery. Do I wire them in series or in Parrallel? I'm assuming parallel since Ham radio requires 12 volts. (I use the Yaesu FT-450)

How long could I expect to transmit CW at 100 watts, and at 5 watts, with two fully charged (ran in parallel)?

I am new to solar energy and I know there are formulas to determine this, I haven't learned them yet. Nor would I trust my results if I did do the math without asking first. Any help would be greatly appreciated.

Can I leave the Batteries in my apartment to be recharged? Or should I build a little Milk Crate out back? I know the batteries produce Hydrogen, But is that only if the batt is overcharged; or does the hydrogen result as a normal prcess of recharging? I live in Ohio so we get lots of sub zero WX. Putting them outside might create

Does anyone else deal with Ice and Snow with their solar panels and how do you deal with that? Does it shorten the life of the panels?

Hypotheticly speaking, (I'm not going to do this!) could I use a 110 volt Battery charger hooked to a 350 watt Inverter, which is in turn hooked directly to the solar panels to regulate the charge on the batteries?

have you looked at this?

http://www.sunforceproducts.com/english/details.asp?id=72#

KA9VQF
12-26-2008, 06:57 PM
I used to have a marine deep cycle battery and a solar charging panel here.

I worried about the possibility of hydrogen gas building up and causing an explosion too, so I bought a plastic case that is made for putting marine deep cycle batteries in.

The case had a port built in one end that was supposed to vent any hydrogen that the battery might produce. I glued a hunk of PVC pipe to the side of the battery case over this vent then ran it up the wall near the window I already had my feed line through and out side. I put enough pipe outside the header board I had the coax run though to bring it fairly near the ground.

One day it occurred to me that the end of the pipe outside was much longer and closer to the ground than the top of the battery so I installed a small computer type muffin fan in the tube just to make sure I had any gas going outside.

I never had any problems with hydrogen build up.

Now a friend of mine had several old car batteries that were his battery backup at his place. They were just laying on the floor in the room he use for his shack. He usually charged them with a big floor model battery charger using mains power.

One day I asked if he wasn’t concerned about hydrogen gassing out of the batteries, his answer was “No.”
He figured there was enough space in the room that the fan from his forced air system would dissipate it before it got to critical mass.

He said the furnace fan was almost always running both summer and winter because he had central air-conditioning which ran when it was warm out and forced air heat that ran when it was cold out.

I guess he was right because he never had a problem with it either.

To figure out how long you can run your rigs on your batteries you have to look up how much power the rig uses on transmit and receive then calculate how long you spend transmitting and receiving. Then how much capacity the batteries have in amp hours and do some dividing.

No one can say for definite how long your batteries will last. There are a lot of variables. You might be able to listen for days and even weeks but not transmit long at all. Even once you can no longer transmit you might still be able to receive for a long time.


Hypotheticly speaking, (I'm not going to do this!) could I use a 110 volt Battery charger hooked to a 350 watt Inverter, which is in turn hooked directly to the solar panels to regulate the charge on the batteries?


I don’t think this would work out because of the law of diminishing returns. I doubt the solar panel would generate enough juice to keep the batteries up enough for the charger to work. If it did you’d have a perpetual motion machine. You’d be better off just letting the solar panel charge the batteries directly. Unless you have a lot more solar panel capacity than the ones you listed have.

My younger brother is using several of the panels harbor freight sells along with a bank of deep cycle batteries where he lives. It is remote enough that the power company wants a small fortune to run wire to his place. Last I knew he had 6 batteries and 10 solar panels. I’m not real sure what he is using for a controller but I know the one harbor freight sold him went belly up.

When things are working right he can run his refrigerator and freezer no problems. In the evening when he wants to watch TV he simply unplugs the freezer to free up enough juice to run it without having the picture go funky.

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