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FT817 & internal batteries

I’ve thought about this for a while and have yet to come to a definite conclusion.

If you use an external power pack (SLAB/LiPO/NiMH/portable fusion system) with your FT817 then do you still carry any batteries inside it?

Of the 165 activations I’ve used my 817 on (the rest where on handhelds) I have only used the internal cells on 5 summits (Tinto, Arthur’s Seat, Cairnpapple Hill, Penvalla, Meall Reamhar). Otherwise it’s been an external power source.

It seems a fair amount of redundant weight to carry when I never use the internal cells. But I’m reluctant to leave them out as they’ve always been a standby supply.

So if you do have an 817 and external supply, do you still carry a viable interal battery (AA or whatever) with you as well?


In reply to MM0FMF:

Yes, Andy, I am using external (2.4 Ah SLAB) power but I have still the internals in my FT-817 … but I do not know why :wink: I should remove them because this original batteries operate for about 5 minutes … bad qualtity.

73, Mario

In reply to MM0FMF:

Yes, I carry them. Compared to the weight of the SLABs (yes, plural) I usually carry for mini-linears etc they don’t weigh a lot, though I admit I’ve thought of removing them. I’ve tried a pack of 10 NiMH as an external supply which I think is better than the internal supply for operating. Yes, OK, I must get organised and get some LiPo batteries.

That said, my rig doesn’t just get used for operating - it’s the driver used for the homebrewed linears and now transverter I’m building (nearly finished, honest) - so it can be convenient to have the internal power available on the bench for a quick test.

I couldn’t be bothered to be continually unscrewing the back of the rig - so I guess the internal cells will stay there.


In reply to MM0FMF:
I seem to remember reading somewhere online that in order to get the ‘full’ 5W out of the FT817 that the internal batteries needed to be installed and charged. It folds back the power otherwise.
Of course I cannot find the link to back up my statement … so feel free to ignore me :wink:


In reply to MM0FMF:


I have always carried the FT-817 with its batteries charged up as back up. I have used them on activations as well: once in November 2008 to activate SP-009, 010 and 011 when I embarassingly left my SLABs at home (which sent the XYL into panic mode) and once on Sugar Loaf Mountain GW/SW-011 when there were so many people around and it was so windy that all I could manage to do was use the FT-817 on its side with its whip to run 2m SSB.

The more options that you have available, the less chance that you will have a failed activation - very important when you’ve driven 300 miles to get there!

73, Gerald

P.S. Now I use an FT-857 and LiPOs, I have the worry that I will leave the battery packs at home, but it has been easier to avoid this happening by pre-installing two battery packs in the backpack which in turn leads to ensuring the other two are in the ancilliary kit box. Now all I have to remember is to charge them!!!

In reply to MM0FMF:

Hi, Andy.

When I’m backpacking, I carry the internal pack inside my FT-817 as a spare but leave it disconnected until it’s needed. There’s a feature with the FT-817 battery icon that will lead you to flatten both internal and external batteries if you don’t.

Also, as has been reported on many occasions, the external power connector on the FT-817 is fragile. If I had the mis-fortune to damage it when out and about and I didn’t have the internal pack with me, it would be “game over”. (I don’t carry a H/H as a spare when I’m backpacking.)

73, Richard (still pining for the hills)

In reply to MM0FMF:

Hi Andy,

My internal battery pack has never been used.

When I got my FT-817 I took one look at the fiddly little connector and thought that if I am going to use an external SLAB anyway I cant be bothered with that.
I have a 7AH SLAB and another 2.1AH one which I use if I am walking any distance.
I find that the 2.1AH SLAB is fine for a single activation.
I have just ordered a charger for LIPO batteries and am just considering how many LIPO’s and of what size to purchase.
I might start with a 3000mah one and keep the 2.1AH SLAB for doing a second summit. What do you think?

David G3RDQ

In reply to MM0FMF:

Hi Andy,

I have the W4RT high capacity pack in mine and it is the first-use battery. My LiPo is the back-up and sometimes is not used. I hardly ever use the 817 on FM because it drains the battery faster than pulling the plug on a swimming pool!

The LiPo was plugged in during our activation of Tinto because somebody who was with us is known for his habit to ragchew and I knew the internal would give out when he used the rig to grab the activation points on 60m!

So the answer is, if the internal battery is of any use then it becomes one of the batteries for the activation, if it is the original Yaesu lump of useless rubbish then leave it out and perhaps take the replacement carrier with NiMH cells in it as a back-up.

Barry GM4TOE

In reply to MM0FMF:

I never used external power supply with FT817ND in portable operation. Just the standard internal batteries, which are enough for about one hour of CW operation.

73, Jaakko OH7BF/F5VGL

Edit: I did not self spot in these activations either.

In reply to K1YMI:

Hmmm… Actually FT-817 have not too good power cord, and with external battery it is possible to see voltage drop up to 2 Volts. It can be critical for some type batteries, which can’t deliver nearly 14V (say, Lithium ones). So, then the internal battery could work as an ‘insurance’. I noted it during the last weekend Field Day, but not figured the problem completely. Anyway I see no great difference in FT-817’s behavior either with Li-Ion battery, internal Ni-Mh battery, or both batteries connected simultaneously. But when I use my home PSU (13.8V, 25A), there is no significant problems with power delivery into TRX. However, there is homebrew power cord connected to PSU (with more thick wires).

73! Alex UT4FJ

In reply to G3RDQ:

Hi David

I reckon to get 3 1hr SSB activations (up to about 30 QSO’s per activation) out of one 3S 2200mAh LiPo, so you shouldn’t need that SLAB for a second summit unless you’re planning marathon activations. I do use a voltage monitor/alarm just in case though - particularly on that third activation!

I keep the internal batteries installed “in case” - it’s kept me going on two occasions when I’ve depleted the LiPo. As Richard says, never leave the external battery connected - there is a constant drain even when the radio is switched off. Can’t say I’ve noticed the internal batteries discharging significantly between uses though - I suspect the culprit is some form of permanent trickle charge arrangement for the internal cells.

73 de Paul G4MD

In reply to MM0FMF:

As Helen tends to use the 817 more than I do these days I will say…‘We’ leave the Internal battery in the rig. This is because on one occasion the SLAB had not been charged as much as we thought (someone turned off the power when we went to bed) and on another we had a problem getting the cigar socket connector to make a consistent connection when it was a bit damp due to heavy mist (it just kept sliding out).

I think I tend to be a belt and braces man. I always carry at least one hand portable as well as a main rig and I like to cover all bands. That way if it is a nice day I can take my time and work every band I can or if conditions are rubbish I can scrape a few contacts somewhere.

Having Helen with a second station means I am a belt, braces and a spare pair of trousers man. Helen and Caroline both have their own dual band hand portables in case we get separated, but they are also useful as back-ups or in the worst case we could take turns to leave the activation zone and work each other.

Not sure what Barry’s problem is with the 817 on FM. I am fairly sure I have had over an hour out of the Internal battery on FM from a summit, which I would guess is about half what you get on SSB. Did six hours once in which I flattened the 817, the 3Ah Slab and two Kenwood PB39 high capacity batteries for the TH-G71E. I still had two PB38 batteries for the Kenwood and the 23cms Icom IC-12E with two batteries but I ran out of time and had to go and pick up the kids from school.

These days I have the 857 and two 7AH slabs which is usually enough. If I ever get around to going down the LiPO route I may have to get a small tent because I am likely to not come down until my batteries are flat or I get my 100th contact whichever comes first.

Steve GW7AAV

PS Could do with an 817 power cord so I can fit Anderson Power Poles but it must be an angled plug like to original. Any ideas where I can get them cheap?

Not sure what Barry’s problem is with the 817 on FM. I am fairly sure I have had over an hour out of the Internal battery on FM from a summit…

Depends what you mean by “THE” internal battery.

If it is the 1Ah Nicad supplied with 817s in 2002, then you’d be lucky to scrape 30 minutes with it. But with a higher capacity internal pack like the OPP817 (2.7Ah), then 2-3 hours (even on FM) is realistic.

There is a fault that can occur just behind the power socket on 817s, which means that while an external power source can continue to be used, the charging cycle for internals cannot. It appears that the charging cycle is working - but no charge is going into the internal battery.

I’ve had this fault twice now, and had it fixed the first time. But I am using SLABs so regularly now that I’ve not built up the will to getting it done again yet. Yet neither have I reduced the weight by removing the internal battery!


In reply to GW7AAV:

PS Could do with an 817 power cord so I can fit Anderson Power Poles but it
must be an angled plug like to original. Any ideas where I can get them cheap?

Mail me. :wink:


In reply to MM0FMF:

I too would be interested to know where you can get the angled plugs from.
Not for an FT-817 but for similar applications


In reply to 2E0XSD:

In reply to MM0FMF:

I too would be interested to know where you can get the angled plugs
Not for an FT-817 but for similar applications


mm0fmf AT hotmail.com

In reply to M1EYP:
This works Tom

"See that the FT817 power jack problem is rearing its head again. The break in the track is not easy to get at to repair. Think that the problem is made worse due to leverage if you use a straight jack plug rather than the 90 degree type supplied. If you use the standard leather case on the rig the best bet is to make up a short lead with 90 degree plug and inline fuse that will go in between the back of the radio and the back of the case. Bring the other end out through the Ext DC hole in the case and fit your two pole polarised plug of choice, we use Tamiya. Our radio control battery is strapped to the side of the 817 and came with Tamiya connector fitted. Fit your FT817 charger with one, then at charging time charge the internal battery via the fitted lead while charging the external battery via its Tamiya connector. No need to disturb the 817’s fragile socket at all and your internal battery is charged and ready if you ever need it. Just be very careful with polarities while setting this lot up!"
Just cut the end foot or so off the supplied 817 charger lead and use it to make the short section that goes in the back of the 817. Stick Tamiya connectors on the charger lead and job done. You don’t ever need to remove the plug from the 817 again.

In reply to G4RQJ:

Thanks Rob,

Just the sort of thing I’m planning but for my FT-290R and for different reasons.
As you may be aware Yaesu in their wisdom put the +ve on the outside of the plug, so sooner or later if you ever disconnect the plug in a Mobile situation you are going to short out the outside of the plug to earth (with resultant arc welding).

I do remember you showing me your FT-817 setup during your talk at the Workington Club. Is it the 9.6v RC Batteries you use?

I have just found a source of plugs on eBay here: http://cgi.ebay.co.uk/Power-plug-DC-female-angled-2-1-5-5mm-L-14mm-/130361122497?cmd=ViewItem&pt=UK_ConsumerElectronics_PowerAdaptors_SM&hash=item1e5a20dec1
I think they are the same as on the FT-817, perhaps someone with an FT-817 could confirm it.


In reply to G4MD:

Many thanks for your comments Paul regarding your experiences with a 2200mAh LiPo battery powering the FT-817.
I do tend to spend more than an hour on summit trying different bands so will need to allow for this .

David G3RDQ.

In reply to 2E0XSD:
<I do remember you showing me your FT-817 setup during your talk at the Workington Club. Is it the 9.6v RC Batteries you use?>

Hi Colin
Yes that’s exactly it. We tried a couple of extra cells for a while to lift the voltage but they made no difference at all so we just use the 9.6v 4600mA battery strapped to the 817 case with black tape. This will easily run a 3hour multimode,multiband activation and can be recharged in an hour, very handy on holidays.
Sorry to have missed your first activation, watch out it’s habit forming!