battery+inverter for TS-830S on Field Day

[KC0BIN]

Has anybody run a Kenwood TS-830S on Field Day with an inverter plus battery power?

That's my plan for this coming Field Day.

At 295W total draw from the rig, I calculated 45AH as the minimum capacity for the AGM battery I need to buy. Sound about right?

[W8JI]

Has anybody run a Kenwood TS-830S on Field Day with an inverter plus battery power?

That's my plan for this coming Field Day.

At 295W total draw from the rig, I calculated 45AH as the minimum capacity for the AGM battery I need to buy. Sound about right?

You only want to run the rig on battery for an hour or two?

[KC0BIN]

I'd rather have enough battery capacity for about 4 hours of normally-paced TX. If I have to invest in a battery, and invest is what it will be for me, I want that kind of capacity.

From my POV, I just don't see the point of buying a quality AGM (Johnson Controls Dynasty) for the single purpose of Field Day ops. That's why it's so important for me to calculate the right capacity. On the other side, I don't want to go overboard on a 110AH; $300 and 70+ pounds.

The same quality standard applies to the inverter. Yes, I can pick up a CCC inverter at Harbor Freight or elsewhere; how long will it really last? I'd rather put my money into a TrippLite or Samlex. Same for the charger.

The inverter and charger specs will have to match the battery capacity.

Sorry to sound like an elitist snit, but I'm very much a quality fanatic. And part-time paranoiac. :rolleyes: The total cost of all this gear is $472.55.

Money well spent, IMHO. But how do I calculate battery capacity for intermittent TX over 4 hours?

TNX for all your help! :)

[KD0CAC]

I do not have all the number for what your looking , and that is the only way to give you back info .
You mention an inverter , so that implies that that radio runs on 120acv ?
If not and it can run on 14vdc , then forget the inverter .
As for batteries , go with FLA - flooded lead acid , all other battery types have special applications that are not necessarily needed for what you want to do , so do not pay a premium for less performance , buy the FLA , then do not but RV / Marine type batteries either , they are not true deep-cycle batteries .
As for sizing , like any equipment / system , design to double everything so as to run at about 50% of rated , or using only 1/2 capacity .
This makes for longer lasting system / batteries .
One of the most common better brands is Trojan , then what your looking for is almost exclusively 6v batteries buy in pairs / or sets of pairs to make 12v .
If you get less battery then you need and run them low too often , that reduces the batteries life .
Same with inverters , buy the large , better brands , buy at least double if not 4 x your needs , once you start going down this road you'll find all kinds of use's , especially if you add solar , wind to charge with , then you can buy a smaller battery bank .
A good link for battery info , Deep Cycle Battery FAQ (http://www.windsun.com/Batteries/Battery_FAQ.htm)
And basically the only and great magazine for alternative energy , Home Power Magazine - Your Small Scale Renewable Energy (RE) Source (http://www.homepower.com/)

[KK7EL]

BIN:
I am not familiar with TS-830s, had to look it up, see it requires 120 VAC to run it. You could get a battery, solar panel, charge controller and inverter to run it for FD.

I think FD is most fun using a fairly simple and portable set up while being in the great outdoors, but that is an individual thing. If it was me, I would get an older smallish HF rig with built in auto tuner, can likely get for about same as you are contemplating spending on powering 830s ($472) and run it from a battery, perhaps charge with a small solar panel, and leave the 830s at home. (I used a TS-50 in past FDs and will likely use an IC-703+ this year fed with an AGM deep cycle and charge with a small solar panel.)

But to your question on battery sizing, you have to make some assumptions on time spent Tx vs. Rx and the total amount of time you will operate before recharging battery. Also, you only want to discharge a deep cycle battery to 50% if you want it to last very long.

Assumptions:
1. Tx is 25% of the time, 295 watts
2. Rx is 75% of the time, 50 watts (my guess, no data)
3. Inverter efficiency 85% (my guess, no data)
4. Only remove 50% of the battery's rated Ah
5. Operate 8 hours before recharge from mains

At 12.5 VDC, 295w is about 28A DC into the inverter, 50w is about 5A. At 25% Tx and 75% Rx, average draw will be 11A (For reference, a fully charged SLA battery is ~ 12.6v.) Battery would need to supply 88Ah to cover 8 hours of op, battery capacity of at least 176 Ah needed. Most economical battery choice would likely be a couple of ~200 Ah 6v golf cart batteries in series for ~200 Ah @ 12v (nominal).

Good luck and hope you have a great FD, whichever way you go.

Edit: I was busy typing when reply just above was posted.

[WB2WIK]

A heavy duty car battery (even purchased new) is a better deal.

I used to borrow Army tank batteries for FD years ago from the local Army Reserves depot. They're bigger and heavier than car batteries (quite a lot heavier!) but one will run a rig like this all weekend without a recharge.

[WA7PRC]

A heavy duty car battery (even purchased new) is a better deal.

Four are even better. This is my FD battery pack:
http://www.geocities.com/bswadener/fd2007/images/P003042.jpg
There's ≈ 320 Ah there... four Interstate "Workaholic Group 27" batteries. Flattened ½" copper tubing serves as bussbar. A 50A Maxi fuse is used to prevent fireworks. 6 AWG wire feeds a homebrew 25A DC-DC boost regulator inside the tent to ensure a steady 13.8V to the TS-430S. Another homebrew DC-DC boost regulator provides 16V @ 4.5A to the laptop computer. Terminal voltage after 24 hours was ≈ 12.25V. :D The litter is made from scrap wood, with reinforcing under the batteries. It takes two people to move it.

One of the other guys brought a DC-AC buzzbox (shown) to recharge his doo-hickey's battery.

[NV5E]

Man, I hope no one accidentally drops a tent pole across those bus bars! How about some split garden hose or something over one of them?

[WA9CWX]

I agree, get a 12 volt radio to work FD. The 830 is a very nice radio, but it IS 120V, not an efficient operation for FD.
IMHO 45 amphour is going to light the finals and run the radio for a very nice hour, maybe two. I use a pair of 6 volt golf cart batteries, opprox 250 amp hour, use that and a IC 703 and you have some real staying power. I run my 703 and even my TR7 on those batteries and they just seem to keep up with the energy bunny....:D

[WA7PRC]

Man, I hope no one accidentally drops a tent pole across those bus bars! How about some split garden hose or something over one of them?
Good point. I've been thinking of fabricating a ventilated wood cover to go over the whole shebang. "Making sawdust" is one of my favorite pastimes. :D


I agree, get a 12 volt radio to work FD. The 830 is a very nice radio, but it IS 120V, not an efficient operation for FD.
Good idea. There are many good & inexpensive all solid-state rigs that would be a better choice. And, you don't risk damaging a fine piece of history like a TS-830. I keep my purty TS-850S at home and have a TS-130S for mobile/FD use.

[WA4OTD]

Why not just use your car battery and plan on starting it every 30 minutes or so? I think this still meets the battery power rules. just don't go to long or you will be amazed at how quick a battery will do down where it won't start your car.

[NO6O]

Why not just use your car battery and plan on starting it every 30 minutes or so? I think this still meets the battery power rules. just don't go to long or you will be amazed at how quick a battery will do down where it won't start your car.

My car battery was near the end of its usefulness last year, and finally drained to the point where it would no longer take a charge. When shopping for a replacement, I discovered a deep cycle battery was available. It was more expensive, but has twice the capacity of the regular replacement, along with a 10-year warranty. This battery has been working great. I typically operate my mobile station while parked, and may go for 2 or 3 hours. The car has never had a problem starting afterwards. I also use a N8XJK Battery Booster, which does a great job keeping the voltage peaked.

[N0AZZ]

I would suggest investing in a second radio for backup in the shack and for field day use at present I use a IC-7000 for that with a AT-7000 tuner.

For power I have 4 cell site batteries (free take outs) that will run all weekend no problems. Others use a portable generator to recharge there batteries on site and others solar a lot of options. I personally don't know of anyone that use AC radios. Well I take that back I do but that is when I take my motorhome and run the diesel generator all weekend with all the comforts of home :)

[KC0BIN]

TNX to you all. WA7PRC's battery litter is keen :cool: and it gives me an idea........:D

The fact that the TS-830S is 120V is part of the ding-dong appeal of this whole project. :rolleyes:

[KA9VQF]

I’m thinking,… the heavy duty off road coaster wagon Harbor Freight sells might look real nice under that battery box.