I use NiMH rechargeables in my Bose A20; they certainly last many hours. Off-brand worked well with Bluetooth off; it did show “low battery” for a long time, but worked well.
I switched to Eneloop when I started using Bluetooth. It works well. Again, the A20 shows low batteries constantly, but that state lasts for many hours.
I start seeing on the “market” Lithium batteries in AA/AAA package format that provide 1.5V. Apparently some do that with a chemistry that provides more voltage, but they convert the voltage with electronics inside the package; others (non-rechargeable only?) use Li-FeS2 which provides a nominal voltage of 1.5V directly, good cold-temperature performance, etc.
The “disadvantage” of the “converted to 1.5V through electronics” is that they will hold exactly 1.5V until (nearly) empty, then will brutally drop voltage very fast. So your device will show “full battery” for a long time, and give very little warning of the battery emptying. While alkaline & NiMH give a more gradual slope of voltage vs remaining capacity.
Using Duracell AA batteries I get a warning a couple of hours before they die.
I use 2300mAh Energizer rechargeables and find them good. Haven’t noticed any dropoff in lifetime vs standard AA.
One problem is that AA/AAA primary cells are 1.55V or so when fresh, but there is no AA or AAA rechargeable replacement which is anywhere near this.
Standard old NICD/NIMH chemistry produces 1.2V and many/most products treat that as a flat battery, so you tend to get a very short life out of it… if it works at all.
The best that exists are the Sanyo (now Panasonic) Eneloop batteries which are nearer to 1.4V and these work much better. We use them at home everywhere. They also have a massive advantage over traditional NICD/NIMH cells in that they have a very low self discharge. Normal NICD/NIMH self discharge in a month or two, especially when they get old.
A properly designed product will either have a selector switch for primary/rechargeable and this alters the battery status determination, or will run down to say 0.8V. But almost nobody does this nowadays. And for primary cells it will give you a very late indication of a low battery; basically only just before it dies.
Peter_Mundy wrote:
I certainly do not recommend rechargeable batteries.
Why would that be? I still happily use my old Bode-X headset with rechargeable batteries. Never had a problem.
According to the manual, the headset will turn off after three to nine minutes (!) of inactivity, given you have set the “Auto off”-switch in the Off position.
There is an “Auto on”-function as well for ship-powered headsets.
Around 5% of my sales are LEMO. I certainly do not recommend rechargeable batteries.
Does your A20 switches by itself after 5min of RT silence?
If you have a USB port or cigarette port USB adapter, you can recharge while in the air, alternatively, you can buy two “Orca 18650 USB Batteries” (40h typically) with USB plugged inside your A20, tough cable setup is a bit flimsy…
I wonder what % of these are aircraft powered? Peter will probably know.
Mine last about 50-60 hours with good reputable batteries (eg. not the cheapest ones from the rack). A lot of times I forget to switch them off before putting them to the case and they do have auto-shutdown feature after a while to preserve battery, so your behavior seems like it needs to be checked out by a Bose service.
