Author Topic: Now may be a turning point for Ham radio and Lithium Ion power  (Read 1051 times)

Offline Carl

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  I ran a test of my favorite (about 1 year old ,12 Amp hour sealed lead acid batter and a Dakota Lithium 10 Amp hour rated cell..

First ..The Lead Acid cell is rated at 12 amp hours (at a 20 hour rate) which means when 4 Amps is the TEST LOAD that you will not get the advertised power from the test battery. I chose 4 amps as a compromise as a typical Ham radio ( 100 watts SSB power) needs peaks of 23 amps or so in transmit and averages about 7 amps while transmitting while in receive 1 to 2 amps is needed. I figured transmit about 1 minute and receive for 3 minutes so the 4 AMP continuous load for testing was 'close enough'.. Two similar rated batteries should test close to the same ability...WRONG

  The slow rate of available power to maintain the 20 hour rate of the Lead Acid cell was too unrealistic...it will run the radio and run it well down to the 11.7 volt test cutoff as many radios become unstable at that voltage. Lithium  started with higher voltage and held higher voltage till right near it's cutoff point. The SLAB is $30 for about 400 charge/discharge cycles while the Dakota Lithium is said to last 2000 cycles ,FIVE TIMES THE CHARGE/DISCHARGE LIFE at $120 and so has economy ...especially when the longer day to day discharge curve is so much more stable and allows a considerable longer single use time per charge.

  The balance/charge/discharge circuit is rated to as much as 15 Amps CONTINUOUS so I still suggest using SSB at 50 watts or so on this current battery as even the Sealed Lead Acid battery would actually not support much above that (50 watt ) level when checked on a good watt meter and dummy load.

Less than 1/2 the weight,as much or more TX output,over TWO and a HALF TIMES the single charge use and FIVE TIMES THE CYCLE LIFETIME (2000) make this a good economy ,tough decision time as ,at least for this battery...we have a real winner. PS A 'regular 4 amp or so charger or 2 amp maintainer both did a great job of charging the battery.

  TEST GRAPH link :   https://drive.google.com/open?id=1NamPqCslXBanBROJghh2mFIB-SRwo9PK

12 Amp SLAB link:  https://www.amazon.com/gp/product/B00A82A2ZS/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

10 Amp Dakota Lithium link:  https://www.amazon.com/gp/product/B00JK06CK8/ref=oh_aui_detailpage_o06_s00?ie=UTF8&psc=1

« Last Edit: May 03, 2018, 02:02:05 PM by Carl »

Offline Smurf Hunter

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Re: Now may be a turning point for Ham radio and Lithium Ion power
« Reply #1 on: May 03, 2018, 02:19:55 PM »
Great information and analysis Carl.

Most of us here understand the importance of backup power, but few of us understand the current draw required from our gear, and more importantly how low in voltage you can get before the radio complains.

This will vary, and requires testing.  I recently had a power distribution setup that prevented my HF rig from getting the full current it wanted.  That limited my TX output to 30-50 watts.  I thought maybe I blew my finals, but it was a crappy DC power situation with too much resistance.

The discharge curve of LiOn is really something.  It's like a massive bonus that's not present with SLA.


Offline DonC

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Re: Now may be a turning point for Ham radio and Lithium Ion power
« Reply #2 on: May 03, 2018, 02:29:56 PM »
As we have done many a battery test together and separately, I wasn't so surprised at the in-depth detail you produced! I've always known that Lithium batteries are the better choice for Ham radio. However, I was skeptical about Dakota Lithium brand. (Several reasons). Now I can purchase with a bit more confidence!

Like Smurf said, many, if not all, Hams know they can use batteries to power their rigs. However, not everyone may know or understand their power consumptions!

Good test! Nice comparison! Can't argue the results!

Offline Carl

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Re: Now may be a turning point for Ham radio and Lithium Ion power
« Reply #3 on: May 03, 2018, 06:09:18 PM »
  Also note that the protection/balance circuit is limited to 15 amps and by the time I have Dakota 'long term tested' that technology will be improved upon a good bit as I also noted that electric BIKES and such...known for heavy current spikes...are the majority of the complaints and failures in the life of this particular battery and protective circuit design. I will have more in use time with this ,but NOTING IT'S LIMITATIONS and staying within the design limits can make for a healthy 10 year or so life from this package . It was worthy of a closer look.The voltage curve while in use is most impressive and lends more promise for the Ham on the go with portable and also solar etc.as the power is kept in balance within the cell package. I do not expect price to get much lower on this technology without some breakthrough in battery chemistry. This is why I felt NOW IS THE TIME.

Offline Alan Georges

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Re: Now may be a turning point for Ham radio and Lithium Ion power
« Reply #4 on: May 03, 2018, 09:08:20 PM »
Nice work Carl, thanks.  Yeah, I think you've shown that LiFePO4s are so overwhelmingly better than SLABs for ham radio that the contest is essentially over.

Offline Carl

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Re: Now may be a turning point for Ham radio and Lithium Ion power
« Reply #5 on: May 04, 2018, 06:00:57 AM »
Nice work Carl, thanks.  Yeah, I think you've shown that LiFePO4s are so overwhelmingly better than SLABs for ham radio that the contest is essentially over.

Only the electronics needs a bit of improvement ....but I would just say that TWO of this same battery would provide 100 watts HF SSB out for at least 6 hours of intense operation without external charge support. This would be a great HOME,PORTABLE,Transportable power supply that should last 10 years or more at better economy of COST SIZE,and weight ...were I capable...I would choose this as an all around power source for Ham radio.