Hi, my T-Beam v1.1 with GPS with a 3350mAh battery last about 2 days with almost no message transfer and no GPS lock (indoors). Just with Bluetooth on. v0.9.1. Is this about right?
Thanks.
I’ve got 1.5 days inside with GPS, I was wondering if it’s not the Bluetooth connection with my old phone that is responsible for the battery life for all devices
I am seeing roughly the same battery life with TBeam v1.1 and Samsung S9
My TTGO V1.1 with a sony VTC5 2600mAh battery lasts 28 hours with the gps hooked up to 7 satelites inside the house.
There is a problem with the TTGO V1.1, it does not charge the battery fully, it charges 4.15 Volts, usually the sony or Panasonic batteries are fully charged at 4.3 ~ 4.5V.
When I charge the battery with the OPUS BT-C3100 charger The battery lasts two or three hours longer
Going up above 4.2 will give your battery marginally more capacity but significantly less service life.
4.15 is actually ideal.
Theoretically yes. But I have a 3000mAh Sony VTC6 battery that I have been using for two years and always charged it with the 4.4v OPUS charger, it only lost 150mAh in two years.
Usually in practice it is not a problem
The 4.15v is only theory that they do not reflect reality but only the brand maybe, some batteries of some brand lose efficiency quickly.
Sony, LG, Panasonic are the best ones.
Then if we buy fake ones from AliExpress it is obvious that they do not last long, especially those that have a value of 6000mAh 
If you look at panasonic datasheet on cycle life they charge to 4.2v and discharge to 2.5v and get around 500 cycles before capacity 70% of new in their tests. You can do your own usage calcs based on 2 days per charge, with more conservative voltages than that you could get 4+ years of continuous use out of a $3 battery. Is there much point limiting run time to squeeze more cycles?
The problem is in letting the battery discharge at 2.5v, if you want a battery that lasts longer it must be interrupted at 3 ~ 2.8v. Another factor that makes the battery last is the discharge current, it must not be more than 1Amp. In my experience Panasonic batteries lose efficiency soon, Sony’s batteries continue after 1000 ~ 1500 cycles to lose their 30~50%
A new problem with batteries is their year of manufacture, if they are never used but old production batteries, they can fail even after 200 cycles.
How are people monitoring/testing the lifespan of a t-beam on the battery? I’d like to harvest the logs, or at least have a start/end timestamp for unattended testing. If I plug in using USB/serial then it gets power…
I have the same question, and i don’t know if is normal… My battery lasts @40 hours inside the house with not traffic and no BT. But I think the GPS module is drawing the battery…
Tbeam uses a lot of power 60-100 ma with gps 100-200ma with wifi on. BLE uses very little power compared to the gps or esp32 24-36 hours is what I would expect, maybe 48 hours at home testing.
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