Kernel included in latest HTC EVO 4G OTA update supports trickle charging
Earlier this year, the big hot-button topics were about the potential dangers of trickle charging and what SBC (superior battery charging) kernels could do to your HTC EVO 4G and battery. There was debate on whether it even could be done due to hardware constraints, and pictures of exploded batteries along with first- through third-hand tales of woe.
Some of this consternation was due to one specific ROM and kernel combo overcharging, pushing batteries past the breaking point. Some was due to some extremely cheap batteries that were just ready to die, and some incidents were just random.
But the realm of trickle charging the EVO 4G was left solidly in the hands of the root world, even though most other manufactured phones supported it. Root got the benefits of another hour or two of battery life, while the unrooted world got a phone that reported 100% charge on the charger, then 10 minutes later dropped 10-15% because the battery was not charged.
G&E reader Howard in Central Florida recently wrote in to ask if anyone else had noticed that the kernel included in the latest OTA, 2.6.35.10-g13578ee htc-kernel@and18-2#1, "turned on" trickle charging. I did some Google searching and found many custom kernels that had been modified to support trickle charging, but found nothing about the stock HTC kernel officially joining the fray.
I unrooted my HTC EVO 4G on Sunday and went back to stock, updated to the current OTA, and ran it overnight using Battery Monitor Widget to keep tabs.
Sure enough, it's trickle charging on my now-stock HTC EVO 4G running a Seido 3500mAh extended battery. Howard's batteries are stock.
It appears when the battery is full that the kernel is still spoon feeding the battery an additional 30-160mAh the entire time it's on the charger, which makes me wonder if this is now considered safe. Is this some plot by HTC to blow up everyone's batteries, or did trickle charging accidentally escape in a test build? Anyone's batteries die or explode after an update recently?
Thanks, Howard! Additional thanks to Jim over at Vaelek.com for help in verifying the trickle.
