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Author Topic: Battery for traveling with mobile!!  (Read 5544 times)
KC9WEK
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Posts: 8




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« on: June 14, 2012, 02:16:09 PM »

I was wondering what would be a good battery to use for my mobile unit while I use it outside the vehicle, say, if was gonna climb atop of a giant mountain?
Thanks
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K6LCS
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« Reply #1 on: June 14, 2012, 07:36:47 PM »

It would help a bunch if we knew the model of rig you are talking about ... BUT, turn down the power of any of 'em to 2-5W, and carry a couple 8AH gel cells with you. Or place the batteries in a cooler, and have a handle for it all. Photos of a couple of my rigs mounted to the lids of Playmate(tm) coolers are on the PHOTOS page at ...

http://k6lcs.com/k6lcs/Photos/Pages/Lunch.html

A good antenna will make all the difference for you ... but, not knowing what radio we're talking about, I'll wait to make suggestions ... (grin)

Clint Bradford K6LCS

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Clint Bradford, K6LCS
http://www.k6lcs.com
KC9WEK
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Posts: 8




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« Reply #2 on: June 14, 2012, 08:04:49 PM »

It is a Yaesu FTM-350ar, and those are some pretty sweet cooler/radio rigs. Sorry I guess more info would have helped. I want to be able to carry my unit with a dual band antenna out on a boat, or beach or just whatever.

73's
Josh(still waiting on my call sign)
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W8JX
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Posts: 5488




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« Reply #3 on: June 14, 2012, 08:27:40 PM »

I was wondering what would be a good battery to use for my mobile unit while I use it outside the vehicle, say, if was gonna climb atop of a giant mountain?
Thanks

If you were climbing where every once counts I WOULD NOT carry a few gel cells. I would find and use a lithium cell battery. It will cost more but weigh a lot less. About 1/5 the weight per watt hour as a gel cell. 
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K7RBW
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« Reply #4 on: June 15, 2012, 06:11:20 AM »

I agree with W8JX. A gel-cell is cheap, but heavy.

If you limit your output power to QRP levels, then 7AH is OK. If you want to use full power, then you'll need more like 18-30 AH (if you want to do it for more than 5 minutes, anyway). I have a 35 AH GelCell backpack and it weighs 25 pounds. Add in the radio and antenna and that's a pretty heavy backpack. 35AH of LiPo batteries will weigh about 8-10 pounds. The tricky thing is that you only need about 25AH of LiPo batteries to get the same useful life as 35 AH of Gel Cell so that'll lighten your load some more. (The reason is because LiPo batts have a higher output voltage so you can use more of the battery's charge than you can with a Gel Cell).

But one thing I'd mention is that taking a mounted mobile radio in & out of the car is usually a nuisance (at least to me, it's been). Just something to consider.
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W8JX
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« Reply #5 on: June 15, 2012, 06:31:04 AM »

The tricky thing is that you only need about 25AH of LiPo batteries to get the same useful life as 35 AH of Gel Cell so that'll lighten your load some more. (The reason is because LiPo batts have a higher output voltage so you can use more of the battery's charge than you can with a Gel Cell).

It is also because LiPo batteries are more efficient under heavy discharges than gel cells and less energy is lost in conversion.
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K5LXP
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« Reply #6 on: June 15, 2012, 06:50:40 AM »

I'm not sure why you would take a V/U FM mobile rig hiking.  Take an HT, and a separate antenna you can set up.  Batteries for HT's are a lot easier to transport, and you're still going to work everything you can hear with 5W.


Mark K5LXP
Albuquerque, NM
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WX7G
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Posts: 5920




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« Reply #7 on: June 15, 2012, 07:59:10 AM »

At 50 watts RF output this radio draws 10 amps on 144 MHz and 12 amps on 430 MHz. The receive current draw is 0.5 amps. The power draw at 5 and 20 watts is not specified. The unit weighs 4.6 lbs.

Something like the Genesis NP12-12 12 volt, 12 A-H sealed lead acid battery from Batteries Plus ($52) would do the job especially if you limit the transmit power. Note this battery weighs 9.2 lbs. That's 0.77 lbs/A-H.

Let's see what a NIMH pack would weigh. Using 10 D cells you end up with a 12 V, 7 A-H battery weighing 1.8 lbs. That's 0.26 lbs/A-H.





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WX7G
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« Reply #8 on: June 15, 2012, 10:20:06 AM »

All-battery.com has 10 A-H NIMH cells for $8.49 each. At 5.7 oz per cell the total weight it 3.6 lbs or 0.36 lbs/A-H.

They stock several Li ION packs too. For example the Tenergy 14.8 V, 10 A-H pack is $160 and weighs 2.0 lbs. That's 0.2 lbs/A-H.

The energy density and cost of these three choices:

SLA      0.77 lbs/A-H,  $4.30/A-H   
NIMH    0.37 lbs/A-H,   $8.50/A-H
Li ION   0.20 lbs/A-H, $16.00/A-H
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WX7G
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« Reply #9 on: June 15, 2012, 06:43:04 PM »

This might be of interest. It's a lithium ion battery box and charger. It's the Windcamp P-box available at hamsource.com for $185.

http://hamsource.com/p-box.html
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VE3WMB
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Posts: 282




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« Reply #10 on: July 04, 2012, 08:38:59 AM »

Josh :

If you don't intend to carry the rig too far (ie. just to the beach, on a boat etc) you might just
look for a battery booster pack. Automotive stores and places like Walmart etc carry these
and often they have them on sale at very reasonable prices.

You would probably want something with a Sealed Lead Acid battery in the range of 12 Ah
to about 22 Ah. Most of these packs have 12V accessory plugs (i.e. cigarette lighter adaptors)
but you could disassemble the case and add powerpoles. Beware that 12V accessory jacks
are not designed to handle more than 10A so you would need to run the rig at 20W or less
which should be fine.  The advantage of the booster pack is that it already has a case / handle
/charger and in a pinch you can even use it to jump-start your car ;-)

Michael VE3WMB

P.S. I have a 22Ah model that I keep as a backup battery for my QRP rigs at my cottage and in
addition to the 12V accessory jack it also has a 5V USB jack which is useful for charging cellphones, iPods etc.

It is a Yaesu FTM-350ar, and those are some pretty sweet cooler/radio rigs. Sorry I guess more info would have helped. I want to be able to carry my unit with a dual band antenna out on a boat, or beach or just whatever.

73's
Josh(still waiting on my call sign)
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