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I'd do it the opposite way. Have a 12vdc? 817 battery with a 12v to usb adapter. There are converters from 12 to 5 volts or an aux power (cigarette lighter plug) to usb.
Mike WA1MAD
I was wondering if it is possible to have a power bank?to charge my phone (while hiking) and also to have it as a backup power source for the?Yaesu.
Not only voltage and current ratings on websites like Amazon are confusing (and probably wrong),?but I'm also insecure if a USB-C to DC cable would?handle the?~2.6 A current the?Yaesu uses to TX?(I use a lot of FT8).?
Is it possible to have a power bank to meet my needs? What kind of criteria should I look for?
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Yep.? You'd be amazed (if that's the right word) at how bad a
modified sine wave inverter is.? I had a XPower 1kw unit in my
initial semi-off-grid solar system (only because it had been given
to me earlier), and tried it out.? I figured there'd be birdies
sprinkled around.? Not exactly.? Instead I found the entire HF
spectrum - ALL. OF. IT. - was wiped out.? Replaced the XPower with a
500va pure sine wave inverter from Victron, and all has been well.
Some images of the A/C waveforms, attached.? I notice that the
Victron's pure sine wave did distort a bit when loaded down with a
number of switching power supplies (wall warts, etc) that had a bad
power factor, but it didn't seem to be bad enough to affect RF
reception.? Resistive loads had no effect on the waveform.
Enjoy,
Greg? KO6TH
Joseph Wonoski via groups.io wrote:
toggle quoted message
Show quoted text
You'd probably be very surprised and disappointed if you look at a
modified sine waveform. It's just a series of square top pulses
alternating positive and negative. Same peak voltage as a sine
wave with short duration pulses. I've never scoped a "pure" since
wave inverter. Has anyone here ever looked?
Joe n1khb?
On Thu, Mar 13, 2025 at 4:48 PM, Greg D via groups.io
Hi Ron,
My caution is to not confuse watts with watt-hours.?
Getting a 300w unit only tells you the maximum
instantaneous AC power that the unit will deliver, but
provides no information on how long that delivery can be
maintained.? So saying "A 300W unit can last a long
time" does not make sense.? Watts has no concept
of time; it's watt-hours that matters.
There can be a rough correlation between the higher
power (higher watts) with larger batteries (more
watt-hours), but that's only cursory.? When choosing a
unit, one needs to understand both the maximum output
needed (watts), and total capacity (watt-hours).?
Marketing-savvy manufacturers may couple a large cheap
(modified sine wave) inverter with the smaller battery,
preying on this confusion, with the ad copy focusing on
the former and ignoring the later.? The general public
often doesn't think about the difference, and because of
the lower cost may get a unit that won't meet their
needs.
Interestingly, you will very often find units that offer
88 watt-hours of total capacity or slightly less; I
believe that's the maximum for some international
shipping and airline travel reasons.
Greg? KO6TH
Ron Wright via
groups.io wrote:
Greg,
Obviously one would not get one of
these power packs to run like a refrig or heater.?
I got a 300W unit to run my soldering gun for
events like putting together Field Day.? Works
great.
Yes, one needs to look at the
capacity for your needs.? And many can power a rig
like a FT817 and also charge for a long time ones
cell phone.? A 300W unit can last a long time.
The point is there are power packs
for many portable use that will supply needed
power.? Some of these power packs even have
wireless charges on top.
73, ron, n9ee/r
Ron Wright, N9EE/R
Hernando Co ARES EC
Spring Hill, Florida also n9ee55@...
On Tuesday, March 11, 2025 at 09:04:48 PM EDT,
Greg D via groups.io <ko6th.greg@...>
wrote:
Mmmm, careful.? At 88 watt-hours, that's
barely more than 7ah at 12v, not counting
internal conversion losses.? The inverter may
be able to source 100 or 300 watts, but not
for long.? 300 watts from an 88 watt-hour
battery will drain it in something like 15
minutes.? Of course the FT-817/818 draws
considerably less - you'd likely get 5+ hours
of use - but there's no Tardis-derived magic
here.? Start plugging other stuff in, and the
run time can drop very quickly.
When looking at these "Solar generators", the
important spec to look at is the watt-hour
rating of the battery.? The AC output spec is
just for the inverter; it's a limit for how
much (peak) power can be drawn, not for how
long.
Greg? KO6TH
Ron
Wright via groups.io wrote:
Martin,
Yes there a lots of power
banks that put out USB power and 12VDC
power and also 120VAC power, all in one
battery box.? I have 2 with 120VAC
output along with USB and 12VDC
outlets.? They come in a verity of power
levels, mine are 100 & 300W.
There are other that can
power a FT817 for hours that put out USB
and 12VDC.
Here is one on Amazon.? No
tsure if you need 120 or 240VAC.
73, ron, n9ee/r
Ron Wright, N9EE/R
Hernando Co ARES EC
Spring Hill, Florida also n9ee55@...
On Tuesday, March 11, 2025 at
08:05:32 PM EDT, Kevin - K5KTM via
groups.io <ktmullens@...>
wrote:
Nice that it’s multi-use but that
thing is huge.?
On Mar
11, 2025, at 13:52, Martin
HB3YDM via groups.io <hb3ydm@...>
wrote:
?
Hey Guys?
check your YouTube the
channel from Jason KM4ACK
this last Video bring s
greatfully battery pack.
?
?
?
or when you have an Car
Start helper this tool is
also very light.
?
?
Vy 73 de Martin HB3YDM
|
Greg KO6TH wrote… You'd be amazed (if that's the right word) at how bad a modified sine wave inverter is. I call them modified square wave inverters! -- 73 Keith VE7GDH
|
Ron,
I second your thoughts about butane powered soldering sets, especially Weller. Have used one for years in my travel and repair kits.
If we believe what we believe Why do we do what we do? ? ?Adrian Rogers
Dave K8WPE
toggle quoted message
Show quoted text
On Mar 13, 2025, at 8:02?PM, Joseph Wonoski via groups.io <N1khb@...> wrote:
?Ron, ? ?You'll never be sorry if you get a Weller butane soldering iron kit. It works anywhere and is especially good in cold weather for larger items like UHF connectors. Only the Weller one in my opinion though. All the other brands seem to be flame design while the Weller is flameless. JMHO, FWIW, YMMV, etc.
Joe n1khb? On Thu, Mar 13, 2025 at 3:32 PM, Ron Wright via groups.io <lt_wright_flg@...> wrote: Greg,
Obviously one would not get one of these power packs to run like a refrig or heater.? I got a 300W unit to run my soldering gun for events like putting together Field Day.? Works great.
Yes, one needs to look at the capacity for your needs.? And many can power a rig like a FT817 and also charge for a long time ones cell phone.? A 300W unit can last a long time.
The point is there are power packs for many portable use that will supply needed power.? Some of these power packs even have wireless charges on top.
73, ron, n9ee/r Ron Wright, N9EE/R Hernando Co ARES EC
Spring Hill, Florida also n9ee55@...
On Tuesday, March 11, 2025 at 09:04:48 PM EDT, Greg D via groups.io <ko6th.greg@...> wrote:
Mmmm, careful.? At 88 watt-hours, that's barely more than 7ah at
12v, not counting internal conversion losses.? The inverter may be
able to source 100 or 300 watts, but not for long.? 300 watts from
an 88 watt-hour battery will drain it in something like 15 minutes.?
Of course the FT-817/818 draws considerably less - you'd likely get
5+ hours of use - but there's no Tardis-derived magic here.? Start
plugging other stuff in, and the run time can drop very quickly.
When looking at these "Solar generators", the important spec to look
at is the watt-hour rating of the battery.? The AC output spec is
just for the inverter; it's a limit for how much (peak) power can be
drawn, not for how long.
Greg? KO6TH
Ron Wright via groups.io wrote:
Martin,
Yes there a lots of power
banks that put out USB power and 12VDC power and also 120VAC
power, all in one battery box.? I have 2 with 120VAC output
along with USB and 12VDC outlets.? They come in a verity of
power levels, mine are 100 & 300W.
There are other that can
power a FT817 for hours that put out USB and 12VDC.
Here is one on Amazon.? No
tsure if you need 120 or 240VAC.
73, ron, n9ee/r
Ron Wright, N9EE/R
Hernando Co ARES EC
Spring Hill, Florida also n9ee55@...
On Tuesday, March 11, 2025 at 08:05:32 PM EDT, Kevin -
K5KTM via groups.io <ktmullens@...>
wrote:
Nice that it’s multi-use but that thing is huge.?
On Mar 11, 2025, at 13:52,
Martin HB3YDM via groups.io
<hb3ydm@...> wrote:
?
Hey Guys?
check your YouTube the channel from Jason
KM4ACK
this last Video bring s greatfully battery
pack.
?
?
?
or when you have an Car Start helper this
tool is also very light.
?
?
Vy 73 de Martin HB3YDM
|
Fantastic, real-life info there in those charts!?? Thanks for doing that testing and posting the outcomes for everyone!
|
One more thing regarding USB-C: , for instance, states outputs of 5V/3A, 9V/3A, 12V/3A, 15V/3A, 20V/3.25A. What does garantee it will output the 12V the FT-817ND needs and not the 15V or 20V and fry the radio?
?
Daniel PY2TDB.
|
The connected device controls the output voltage, you would use a cable configured to "tell" the power bank to supply it with 12v.
?
I don't think anything 'guarantees' the power bank won't provide a different voltage, just the presumption/expectation that the devices will work as designed.
?
To power an FT-817 type of radio with 12 volts, you would use a cable designed to priced the desired voltage, like this:
https://a.co/d/hNy4MWO
?
Hope this helps,
?
Ken, N2VIP
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?I’d stick with a 12 volt lifepo4 battery and use converters to power/charge 5 volt usb devices. I recently added the Windcamp battery kit?designed for the 817/818, it’s about $75. Also 3 18650 batteries in a 3 battery case work well and can be recharged with a 4 cell charger. Don’t risk messing with alternative power sources.?
toggle quoted message
Show quoted text
On Mar 22, 2025, at 7:26?PM, Ken N2VIP <ken@...> wrote:
? The connected device controls the output voltage, you would use a cable configured to "tell" the power bank to supply it with 12v.
?
I don't think anything 'guarantees' the power bank won't provide a different voltage, just the presumption/expectation that the devices will work as designed.
?
To power an FT-817 type of radio with 12 volts, you would use a cable designed to priced the desired voltage, like this:
https://a.co/d/hNy4MWO
?
Hope this helps,
?
Ken, N2VIP
|
Also, note - the power bank you linked to claims 20,000 mA, but at what voltage? I suspect at 3.7 volts, the voltage of the internal cells - 20,000 mA at 3.7 volts will be closer to 5,000 - 6,000 mA at 12 volts, maybe less. That may or may not meet your needs - that is something to consider when choosing power source.
?
Ken, N2VIP
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I have a 12V 24 aH (13.8V 24,000 maH) LiFePo as the largest practical size pack. I have two sets of Anderson Power Poles for 12V gear and two 12V to USB-C plug 5V 3A step-down inverters (for raspberry Pi + QHD screen or whatever). I got it to power my FTdx10, but of course it's fine for my FT817ND (and optionally PAs). It's charged by 2 x "100 W" solar panels easy enough to put in a small car. I mean to get a car charger and mains charger. The MPPT controller is a Victron (cheap model with no BT, so I had to interface the TTL serial to change it from Lead Acid to LiFePO4.)
Lives in a carry-case with shoulder strap along with LED meters.
The LiFePO4 has 3000+ full cycles rating (down to 10%) and a 1/3rd of weight of Lead Acid. Safer than LiPoly/LiIon. The cheap Lead Acid Gel / SLA for emergency backup (UPS, lights, Alarms) don't even quote cycles. The more expensive ones (more expensive now than LiFePO4) are about 100 to 200 cycles, but only if not fully discharged. The 200 cycles is about 70% usage.
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Or search for "aili 18650 powerbank".
This is the kind that satisfies the requirements. I haven't tested it for EMI with my FT-817 yet. Using it as an extra power for laptops.
It can charge from a 19V laptop power adapter with 5.5x2.1mm barrel tip and can output 5/6/9/12/15/19V selectable by mechanical switches on its 5.5x2.1mm socket. Has a USB-A output for the phone as well.
The best part for field operation is that you can replace 18650 cells with ones pre-charged at home, so essentially "unlimited" capacity.
You need to understand what you are doing, like closely matching the 2 strings of 3 cells each when installing. Instruction manual is not included, but can be found online.
?
73, Mike AF7KR
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On Wed, Mar 26, 2025 at 09:44 PM, vbifyz wrote:
You need to understand what you are doing, like closely matching the 2 strings
of 3 cells each when installing. Instruction manual is not included, but can
be found online.
That sounds like a really bad design. The cells do not stay matched and how do you match capacity? Any proper charger for multiple series LiIon cells needs a controller than measures each cell.
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Sorry, the configuration is one 3-long string of 2 cells in parallel (not 2 parallel strings).
I dug deeper into the reviews. People say there is indeed a built-in charge balancing in the Aili powerbank.
The pairs of cells still must be closely matched, but this is true for all other powerbanks where cells are connected in parallel. I am using cells from old 3S2P laptop batteries, where cell pairs are already welded together.
?
73, Mike AF7KR
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David Wilcox K8WPE
Craig Bailey - N4CN
Michael Davis
Mike EI9FEB