Portable Power Supply

Couple of folk ask me what Portable Power Supply i use - Tracer Power Lith Battery Pack 12v 10ah. Available with diffrent sizes and amps


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Hi - thanks for the info, looks interesting.

I looked up the data sheet for this:

…and it looks like it’s a 3S lithium battery pack with a voltage range of between 11.1V to 8.25V which would be great for use with my handheld, although wouldn’t work so well with my FT-857. I like the built in battery management feature - I have to manually monitor mine and if I run it down too much, my battery gets trashed!

73 Mike

£170 for a battery!

If anyone has that kind of brass to spend get in touch because I have a few Brooklyn Bridges for sale.


HI Mike

I have used this with 857 ,although iam a M6. and i dont have a shack at my home QTH . No expert on the matter but two folks asked yesteday ,and if your running say somthing like a 817 then this i belive would make a good partner. I have the 12v 10Amp one@ £140+vat i have had this over 12mths and has never let me down ,i supose its case of how much Portable work you do vs your budget

See this Video from Jason why i went for this product



Mind you with charger my lifepo4 was nigh on near £100.

But worth it


It’s a massive overkill for an 817. That radio will deliver full power even when only fed around 10V (I can’t remember the exact spec). It means that for an 817 a 3S LiPo will work fine thus saving significant amounts of money. There are lots of other QRP radios that work fine off a 3S LiPo too.

There are plenty of radios that need 12 to 12.5V as a minimum. The FT857 and IC706 spring to mind. For them nowadays the LiFEPo batteries are a better bet but more expensive than LiPo. But still cheaper than the Tracer solution.

Prices have risen for LiPo tech, partly due to the Pound being worth pennies, but for 817 users a 2.5 3SLipo and slow charger can be had for £35 inc. VAT & delivery. But that is specifically for radios like the 817 that do not need over 12V to give full output.

There’s nothing wrong with the Tracer other than the price, they seem to have a reasonable reputation as a company. But there again if you want a packaged solution with a matching case then you will need to spend some green. I have a problem with that as my wallet was welded closed when I was a child.

My experience with the Tracer batteries are that they fall over and go low voltage using higher power with radio’s like the FT-857 running at 50 watts or more. I had an 8 AH one with the posh case bought new - no good, it let me down at anything more than 30 watts on SSB (audio distortion) so I sold it to a shooter.

I prefer to use LiFePo myself or 3S LiPo as a second choice. Both types need a bespoke charger.


These are good, I have two. Complete with charger. Other batteries are available. Overkill for an FT-817 yes, but you may decide to run other radios such as a 2m FM 50 watt radio or FT-857, IC-706 etc in the future.

I also have two of these which are also good and use the same charger as for the 7 amp one without problem:


I got mine from the UK from Hobbyking. Other batteries are available.

73 Phil

The 857’s manual says the voltage range is 13.8V +/- 15% … so, 11.7V - 15.9V. It’ll still work at voltages less than this but problems such as signal distortion and other weirdness may occur such as random configuration changes (been there, done that). At 10W the effects will be less than at 50W. Used with an 817 or handheld though, no worries.

Was this Tx distortion? I’m trying to sort out an FT 857 that is receiving poor audio reports on SSB. I use this sort of battery and the voltage seems to hold on Tx up but maybe it is the source of the problem??

Be interested in your thoughts/comments.

I use this Tracer 12 10Ah battery and never had a problem with it. I’ve had it for nearly 3 years and done over 30 activations with it. I mostly run 40-50 watts and use it with my FT-857 now but have used it with a Ft-817 and a Hardrock 50 Amplifier.

It is expensive but my main reason for buying it was that I could bring it overseas. I was a bit sceptical about taking HobbyKing batteries with wires floating around and how dodgy it might have looked. I didn’t want to lose my radio due to a dodgy looking battery setup. Its pretty light as far as weight is concerned so no problem there.

I did have a please explain in Dubai about the radio FT-817 and what is this ?. As far as the battery was concerned. I said it was a battery and was asked what for and I said to power the radio. Mumble mumble in Arabic and they walked off.

I’m very happy with the battery and happy to continue using it for my activations. It does come with a car Charger and the main Charger is a plug pack so no problems with balanced chargers etc. Just plug it in and away you go.

I’m very happy with it and would buy one again.

John VK6NU

Yes Compton it was TX audio distortion. No distortion or problem when using CW at up to 100 watts with the same battery, but it didn’t like SSB. My FT-857 has done many activations and been knocked around a fair bit so it is probably a little out of alignment, hence it was more likely to distort I believe when the voltage falls below 12v. I never sent the radio away for alighment or repair. I just used a battery that didn’t sag when drawing 10 to 15 amps. Maybe I got a bad Tracer battery…
I have had no complaints of distortion once I changed over to LiFEPo4 batteries after finding out from Klaus DF2GN the secrets of his success when I met him on an activation in Germany in 2014.

Try operating your radio at the 10 watt level with that Tracer battery. You could find that the audio is clean.

73 Phil

Others have reported this to me also when using the FT857 and the battery pack voltage is dropping into the 10 to 11V range…
Richard // N2GBR

Ill confirm the same. I only use 3S lipos with the radio. All perfect with the lowest usable 3s voltage.

The FT857 voltage range is 13.8V +/- 15% … so, 11.7V - 15.9V

So this works perfectly with a 4S LifeP04 type pack. I constructed a 3P4S pack of A123 26650 cells with a pack capacity of ~8.5Ahr. voltage range of 14.3 down to about 10V min.

As reported, contacts report “Strange audio effects” when the voltage is less than 11.0V
Richard // N2GBR

Interesting mixed reviews …anyhow just confirm what was in my orginal post iam a M6 and iam restricted to 10w ,so yes it works fine for me with the 857 …I was just ask by two folk on QSO what i was using and posted a few pics to confirm …Iam sure they got a few diffrent options now…

That’s only transitory Rob. You’ll be a 2E soon then an M0.

On my last activation I ventured on to 20m SSB with my FT817. I’d had the rig on CW with no problem, but when I switched to SSB, I noticed some strange noise in the headphones during TX. Being experienced enough to notice that something wasn’t right, I investigated. I noticed that the voltage reading on the FT817 display was fluctuating to 8V under SSB TX. I had a 3000mAh LiPo plugged into the rear jack on the rig, oh no I thought, the power jack had decided that it had had enough after nearly 16 years of service.

I was pleased to soon discover that the power lead had broken at the fuse holder! As luck would have it, I had a gas powered soldering iron, solder and tools with me on the summit! :wink: I did a repair in the field and I was able to continue with my activation. I’d obviously been running off the internal battery beforehand.

Undervoltage, even at low power levels will cause problems on TX. Those 100w rigs are power hungry beasts and hopelessly inefficient at low power output.

73, Colin

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That was an amazing bit of luck Colin. :grin:

Hello everyone!

Until recently we used (my brother and I) a motorcycle battery for SOTA activations. For the last activation on Sunday we got (4) LiFePO4 batteries and they worked pretty well. The batts are 3.2v / 10Ah and with the FT857 at 35W we could operate for more than an hour. Whenever started txing the voltage would drop to about 10.6, but it would stabilize just under 12v after a couple of seconds. Nobody complained about the audio, so I hope all was good. The cost was around 100 euros for all four, and they weigh around 1.2 kilos total (much lighter than the old motorcycle batt). The problem was to fit them into some sort of a box for added protection, which we did by using threaded rods, nuts and some plastic sheet. Then everything was put in a plastic case we bought in a hypermarket (Carrefour I think it was). The end result is a bit bulkier and a little heavier than the batteries alone (with some 200-300 grams extra), but is much stronger and can be further improved with padding to keep the cold away. If anyone’s interested, here’s a PDF with some pictures of the case: LiFePO4 field case PDF

73, Bogdan

Very neat. I hope it keeps working well for you.