[Desire HD Q&A, Help & Troubleshooting] davemusic12:
Re: the OP about Battery drain

I too have been following CM11 nightlies since early January.

I am fortunate enough to have 3 DHD's to play with. (1 - mine and 2 "experimentals").

My experience with the battery drain issue is;

If I turn on Aeroplane mode and then turn WiFi back on - I have good battery life.

In other words - I turn the radio (for cell calls) off.

(I grant that this is not useful for receiving phone calls. However, this is experimentation).

I live in an area where I have very poor cell reception.

Initially I found that I had enormous battery drain with the radio on. I think this was because it was searching for a good cell signal all the time.

BUT........ no, that wasn't the only reason.

I placed one phone in a location where it had 3 or 4 bars and other "signal verification" apps said there were 4 towers in view.

I got a slightly reduced drain. But, still it was big. When I say big - I mean ..... "sitting in view of 4 towers and doing nothing.... battery drains wihin 7 hours".

Another phone has no sim installed. It still has battery drain if I don't turn on Aeroplane mode.

With my 3rd phone - I turned on Aeroplane and turned Wifi back on. Then I put that phone in my bag and forgot about it. 5 days later I noticed a small flashing light coming from my bag. Yep! - it was that phone. The battery was down to 1% but, it had been on for 5 days. Admittedly it had been doing nothing except waking to check mail and Viber.

I am also trying the "Nexus 5 Experience" (based on Mustaavalkosta's kernel/effort). So far (only 36 hours) it appears to display the same behaviour.

I appreciate that the radio "costs some battery". Most items that I've read IMPLY that the cell radio consumes the least out of Cell, Wifi, GPS.

(FYI - I have been using "Wakelock Detector" and "Battery Doctor" to detect anything untoward and/or kill it. The only "greedy apps/processes" that I see are "Google Search" and "Viber". But, their greed is insignificant compared to the radio)

Last year I had only 1 DHD. I had a sense ROM (Viper) and my memory tells me that I didn't have the same amount of drain. But, I could be wrong. I know I had an older radio. I updated the radio in October and found that I had better signal so I stayed with it.

I have attempted to revert to that radio with CM11 but, it couldn't find any signal.

My question (for anyone who may have some thoughts) is;

Could there be some sort of radio incompatability going on?

I recall that one needed to have the correct "RIL" with sense roms. The "RIL" was a 'compatibility library' (or something) that "connected" the ROM with the radio. (or something like that). However, that's not the case with "Non Sense Roms". OK. I accept that the interface between the main OS and the radio is different. But, the radio's are a chunk of code that are "interfaced to". I don't think there's any sounce. So, the CM team (and other teams) must have done some reverse engineering OR found some document that specified an API so they could interface with the radio.

I would be facinated to know if there were similar problems with other breeds of phone/radio. I guess that most phone designs are similar inasmuch that they seperate the "radio cpu/chip" from the "main phone cpu(s)/chip(s)".

But, I am not a "phone coder" and it's all just supposition.

I will "revert" one of my phones back to a "sense" version and see if there's similar behaviour.

David

Radio: 12.69a.60.29U_26.17.14.11_M

Kernel: 3.0.101-3.3+hybrid-g2ee05c4

3 X DHD all with new 1500mAh batteries.