Hi does anyone have any experience of using an Anker Pro2 20000mAh portable power bank. I would be keen to hear your opinion on using this to power a FT817.
Thanks
John
It’s the wrong type of power pack, very pretty but not really what you want.
- rather expensive
- has inbuilt switched mode electronics, no guarantee it will be rf quiet
- the specified capacity 20000mAh is in “marketing mAh” and the real capacity is likely to be well below that
You should have a read through the archives were you will see loads of recommendations for batteries and chargers for use with an 817. There are a bewildering number of options which makes picking something harder.
Cheers, Thanks for the heads up.
John
I have an Energizer XP18000 and an XP8000. Either work well, and have a nominal 12V output perfect for the '817.
2500 mAh flat 3S LIPO from Hobby King fits nicely in the battery compartment and lasts for 3 x 30min compressed audio SSB 5W activations for me.
You’ll need to do some work with the cable connections - all documented by myself and others at various places on the Internet.
73 Ed.
John, as Andy mentioned, the ratings they use are very much marketing ratings - i.e. intentionally misleading to make the buyer thinking they are getting more than they really are. The 20Ah is the total of all the cells at the lowest voltage (for LiPo, 4.2V). So at 12V, you are going to get at absolute most (exluding inverter inefficiencies) about 6Ah capacity - real life maybe 5Ah and that would be totally flattening the battery.
Best bet is to buy the batteries that the RC crowd use (and many of us also use) - far cheaper and also lighter. I cannot comment on electrical noise of the power bank devices, but to me it adds another potential noise source to your activation. My advice, buy one and try it if you wish, but you are much better off with the RC type batteries.
Note, for the 817 I recommend the 3S LiPo batteries - they are damn near perfect companions for the 817. Do NOT buy the 4S LiPo batteries as unless you use a regulator or a diode or two inline, the fully charged voltage is outside of the recommended specs for the 817 (and pretty much all other 12V powered radios).
Matt
VK1MA
Thank you all for your comments. I am new to SOTA and so far have only activated on a couple of occasions using a 706 2 g and carrying a couple of 7ah slabs. It didn’t take long before I decided to lighten my backpack and invest in a FT817 ND, but not sure what option to go for power wise. What modifications do I need to make to the LiPo’s, is it just a case of changing the output leads?
Thanks
John
I’ve managed to find more info about LiPo and LiFe4 batteries in the old reflector.
Thanks
John
No worries - apart from changing the connectors to Andersons (and using a balanced charger for LiPo’s), only other thing is some form of power usage monitoring. Some use voltage alarms, but I use a “Watt’s Up” meter from Powerwerx in the US - that way I know exactly how much of the capacity I have used and theoretically how much I should have left. Note that they recommend not using any more than 80% capacity of LiPo batteries - I tend to limit to 50-60% before swapping to another battery if needed.
Matt
VK1MA
If you use a 3S LiPo as an external power supply: Only changing the output leads. Getting the correct DC connector for the FT-817 can be a bit tricky as this is not a widespread dimension of barrel connectors. Getting the Yaesu EDC-6 cable is an alternative. Or simply cut the wire of the supplied Yaesu charger and put some standard connnectors (power pole, banana) in.
Some operators replace the standard NiMH battery pack inside the FT-817 with a small 3S LiPo. This requires a bit more fiddeling.
@VK1MA
As I normally use less than 50% of my 3S LiPo or 4S LiFePO4 I found out, the voltage display of the FT-817 completely suffices. The cells of a decent battery do not drift too much apart unless you discharge it more than 80%. I always carry a simple single cell voltage monitor with me but in fact I never used it during an activation.
73 de Michael, DB7MM