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FT-817 internal LiPo


#1

Hi all,

I found a LiPo (11.1V / 3.6 Ah) which fits into the internal battery case of the FT-817. First used yesterday on a cold summit without problems. It can be found on ebay (.de) with a search for “LiPo Sanwa M11” (RC TX), and is manufacturer labeled “LRP”. The LiPo discharg purpose is only for low current, but the connection cables are still thicker than those in the 817, and LRP mention a charge with 1C which is also more then the 817 need.

Photos: http://www.dl1dlf.de/ft-817-lipo-intern

73 Jörg DL1DLF


#2

In reply to DL1DLF:
Hi Jorg, a UK supplier on ebay is offering a 3 Pack for £54 + shipping…quite pricey. A shame you cant buy them singly

73

Adrian
MM0TAI


#3

In reply to MM0TAI:

Hi Jorg, a UK supplier on ebay is offering a 3 Pack for £54 +
shipping…quite pricey. A shame you cant buy them singly

That’s a 3-cell pack that is a single battery, not 3 batteries.

It’s also only 11.1 volts so you won’t get full power from the 817 (it need 12v to do that).

Colin G8TMV


#4

In reply to G8TMV:
Ah good spot Colin!!! That makes it even more pricey!!!

My 817 runs full power from my external 11.1v lipo, I think.
Im now away to double check that :slight_smile:

Adrian


#5

In reply to G8TMV:

It’s also only 11.1 volts so you won’t get full power from the 817 (it need 12v
to do that).

No it doesn’t. Please check the reflector archives where you will find very lengthy discussions about the fact the 817 needs around 10.9V to give full power on all bands.

Andy
MM0FMF


#6

In reply to MM0FMF:

No it doesn’t. Please check the reflector archives where you will find
very lengthy discussions about the fact the 817 needs around 10.9V to
give full power on all bands.

Ah, you are correct. BUT, the default is not to run full power when running on internal batteries whatever the voltage. The manual makes it clear (p28) that the rig auto selects 2.5W when it detects internal power being used. So users need to override that. I suspect that is where the confusion comes from.

Colin G8TMV


#7

In reply to G8TMV:

Hi Colin,

the switching 2.5W/5W does not matter if the voltage supply is connected internal or external. The LiPo internally attached, the FT-817ND starts on 5W. When the voltage decrease under 11.5V, the 5W symbol flashes, but the 817ND will remain on highest output.

73 Joerg DL1DLF


#8

In reply to MM0TAI:

Whether this one fits in a FT-817 or not I don’t know, but it’s much cheaper. USD 40.87 incl shipping

http://cgi.ebay.com/RC-Battery-3600mAh-11-1v-35c-LiPo-Akku-3S-35C-fur-trex-/300521089634?pt=AU_Toys_Hobbies_Radio_Controlled_Vehicles&hash=item45f873ea62

73 Anders SM0HPL


#9

In reply to DL1DLF:

the switching 2.5W/5W does not matter if the voltage supply is
connected internal or external.

This is incorrect see my last post and below.

The LiPo internally attached, the
FT-817ND starts on 5W. When the voltage decrease under 11.5V, the 5W
symbol flashes, but the 817ND will remain on highest output.

No, it is complicated. The true situation is as follows (tested on my British spec 817ND with the standard battery):

Powering up from default (factory state) on internal power you get 2.5W.

This can be changed to 5W (symbol flashing) and the new state will be remembered, even if the rig is switched off and back on, until external power is applied. At which point the symbol disappears (rig still on 5W).

Removing the external power makes the rig revert to 2.5W i.e. the default state.

Colin G8TMV


#10

In reply to G8TMV:

How can you say my post is incorrect when you are using the standard battery? You’re probably right Colin, and me too. This thread is about a internal LiPo. The charged LiPo starts around 12.4V, switching on the 817ND it initiates with 5W, indifferent internal or external plugged. The standard battery you are testing supplies less then the changeover voltage by 11.5V.

Joerg DL1DLF


#11

Hi, the cheapest adress for LiPo’s I could find is here http://www.hobbyking.com, I’ve been searching for one that fits inside the FT-817 but up till now no succes … they have so many. I use their “ZIPPY Flightmax 5000mAh 4S1P 15C” with a diode bridge, to pull power down. I always carry two of those. The weight … no problem and I can work easily for a whole day at 5 watts output.
73 PD2PC Patrick


#12

In reply to DL1DLF:

Jorg,

marked as TX-only are we sure that it can handdle the 2As of FT-817 on transmit? (th 1C CHARGE means that the maximun allowable charge current is 3,6A. NOT that LiPo will stay cool giving out that current). Except is a common assumption with Lipos which i dont know.

If yes, its a very usefull post, thanks a lot.

Someone can find it around $58 from many sources. Just Google for “Vtec 79981”.

73, Panos, SV1COX


#13

Been using a couple of eBay-sourced LiPo packs for a few months now. Niether fits inside the 817 but both have integral charge/discharge circuits, come with wallwart chargers and both were cheap! See my blogette at

http://martinsrant.blogspot.com/


#14

In reply to G4EFE:

I’ve got one of the black packs shown in your photo and as you say it works very well. Unfortunately the charger supplied with mine self destructed about the third time I used it. I now use my iMAX B6 charger which can charge many different types of batteries.


#15

In reply to G4EFE:
Hi

Do you have a link to the ebay item you bought please? The black pack is just what i am looking for!! Found a couple of similar items on ebay but they are around £50 each for half the capacity…

Not sure if you bought the 6800 pack as a packaged item already in the case or boxed it up your self?

Cheers

Tim

G4YTD


#16

In reply to G4YTD:

I have found this one on ebay; item no. 280627726516. Not bought it as the pack of 11 (+ fuse) 2900 mAh AAs are doing OK.

73,
Rod


#17

Tim, Rod: yes, that’s the one. I asked if they would would send it as a ‘gift’ so as not to attract the attention of customs. Not only did they mark up the package label as required but they also sent it in birthday wrapping paper complete with label!

The double-ended DC lead that comes with it will need to be modified to be compatible with the 817. Replace one of the plugs with one suitably sized to connect with the rig. If you need one please let me know as I had to buy 10!

73 - Martin


#18

In reply to M0JLA:

I have found this one on ebay; item no. 280627726516.

120645075335 appears to be the same thing and is even cheaper.


#19

In reply to M1MAJ:

They also appear to supply a localized mains plug rather than US only. Does look like very good value.

Rod


#20

In reply to M0JLA:

The charger is rated at 350mAh and the cell pack at 6800mAh. So the charge time from flat must be in excess of 19.5 hours. However, it does look good value and makes you realise how 20th century SLAs are.

Andy
MM0FMF