Primarily for general aviation discussion, but other aviation topics are also welcome.
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By timjenner
#1548080
Can anyone advise how the 550 gets on with low self discharge Ni-MH AAs, especially transmitting which I guess needs quite high current for short periods? I'm heading to the US for a couple of days and am torn between picking up a 550AA for $200 or a 450L for $250. The extra $50 feels like a lot just for the lithium battery if AAs work fine! Only interested as a backup com unit so the nav features of the 550 aren't relevant to me.

Cheers,
Tim
User avatar
By timjenner
#1548099
Fair point, Paul! I'd actually use it for the odd ATIS check before startup, etc so not solely as a backup. I always worry about part used alkaline batteries, as least you can top up rechargeables.

Cheers,
Tim
User avatar
By rohmer
#1548110
The 550 handbook states that 6x AA alkaline batteries should be used and warns against the use of rechargeable batteries because the SBT-12 battery tray does not have the thermal and over-current protection circuits that are required when using Ni-Cd or Ni-MH batteries.
User avatar
By timjenner
#1548164
Hmm. Wouldn't have thought those protections would be needed unless charging the batteries in the radio? On balance though I'm coming down on the side of the 450L - fresh alkalines in the AA tray for emergencies, lithium battery fitted normally and generally less faff all round.

Interestingly the price difference is much higher between the AA and L versions in the US than here. While the 550AA is the same price in dollars as it is here in pounds the lithium versions are more. With the rubbish exchange rate I may as well just stop at Martin Lynch in Slough on the way back from Heathrow and pick up a 450L for £220 (with a UK charger!).

Cheers ,
Tim
User avatar
By Ridders
#1548171
I've only ever used non rechargeable cells in the pack.

I have it sitting in flight bag ready for use, with the headset adapter cable tied to the unit.

I've used it at our fly in for A/G comms when not on the main radio, it worked on the cells for a good length of time with no need to replace.

I've replaced the batteries twice in the couple of years I've had it.... There is a battery indicator on the screen that shows when the batteries might need replacing as the level drops down on transmit under load when they do.

The voltage on the batteries when on load is difficult to measure due RF but with the unit still working but showing near empty on TX I estimate about 1.28v on load and off load (recieve) the batteries were showing 1.35v.
New batteries measured 1.61v off load (Duracell Ultra Power).
If your really worried about cells going flat, you could pack some spares in your bag or even buy a spare bat pack ready to clip in.

Did I mention our Breakfast Fly In is on the 5th August? :D
By Chris Martyr
#1548177
Ridders wrote:Did I mention our Breakfast Fly In is on the 5th August? :D


Sorry : When was that again.. :D

Tim , I have used the ordinary AA dry-cell batteries for years in my Icom handheld , which incidentally is my primary source of VHF comms in my open cockpit homebuilt.
I fly pretty regularly and can almost get by for a whole 'season' on one set. One of my pre-flight checks is to press the PTT and see if the 'Lo-Batt' message comes up. If it doesn't then you can be fairly sure that there is sufficient battery capacity for the flight.
If it does come up , then just whack a spare set in.... :thumright: Easy.
User avatar
By Sooty25
#1548199
timjenner wrote:With the rubbish exchange rate I may as well just stop at Martin Lynch in Slough on the way back from Heathrow and pick up a 450L for £220 (with a UK charger!).

Cheers ,
Tim


You'd also have warranty support in the UK AND you would have supported two UK companies, the retailer and Yaesu UK. The warranty alone must be worth the meagre saving.
User avatar
By PeteSpencer
#1548254
timjenner wrote:Fair point, Paul! I'd actually use it for the odd ATIS check before startup, etc so not solely as a backup. I always worry about part used alkaline batteries, as least you can top up rechargeables.

Cheers,
Tim


I stopped using the supplied rechargeable battery with my elderly iCom as it always seemed to be flat when I needed to go flying.

I fill it up with new alkalines every 6-9 months regardless, providing an endless supply of part used AAs for grandchildrens toys house clocks etc.

I use it quite a lot for getting departure ATIS, requesting start up,etc to save switching the master on and off and it sits in my flight bag with headset adapter rubber-banded to its side.

Peter
User avatar
By Ridders
#1548260
riverrock wrote:And if you're getting the lithium battery one, the charger might not be dual voltage, so wouldn't work here anyway ( I have the 750 and charger isn't dual voltage).
interesting!
The 550 AA cell version from the US comes with a 12v cigar lighter cable, so it's the AA cells or that. I know some aircraft have cigar lighter outlets.
User avatar
By rohmer
#1548262
Beware the cigarette lighter power adapter with the 550. Even with the the supplied toroid fitted I found its switch mode regulator to be electrically noisy so I've replaced it with a linear regulator and filtering capacitors giving a steady but noiseless 8v output.
User avatar
By flyingeeza
#1548277
rohmer wrote:Beware the cigarette lighter power adapter with the 550. Even with the the supplied toroid fitted I found its switch mode regulator to be electrically noisy so I've replaced it with a linear regulator and filtering capacitors giving a steady but noiseless 8v output.

Interesting. When do you experience the ciggy-socket noise, transmitting or receiving?
User avatar
By rf3flyer
#1548303
flyingeeza wrote:
rohmer wrote:Beware the cigarette lighter power adapter with the 550. Even with the the supplied toroid fitted I found its switch mode regulator to be electrically noisy so I've replaced it with a linear regulator and filtering capacitors giving a steady but noiseless 8v output.

Interesting. When do you experience the ciggy-socket noise, transmitting or receiving?

I expect rohmer is already aware but there is an interesting post on this very topic on the LAA forum
http://services.lightaircraftassociation.co.uk/phpbbforum/viewtopic.php?f=4&t=5137#p24409
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