Quote Originally Posted by dhisky View Post
It doesn't need to be technical as it should be 12v when engine off or 14v when engine is running. If casa can tell you na 50% na lang ang battery life, I can't see a reason for them to not display it the way where anyone can understand it. Again with the technological advancement, they can simply place a battery icon in the dash like the one we have in our cellphone where you can simply see the battery life. Or simply place a flashing red battery icon on the dash to warn you that you need to change the battery na.

As for the counter would have been a cool feature as well.
At most, a voltmeter can only work as a redundant system for the "battery not charging" idiot lamp. For the most part, when you turn off the ignition and switched to ACC, you can get a reading between 11.5 to 12.5 V. Getting an 11.5V reading doesn't mean that the engine will not start the next time or that the battery is bad. Conversely, getting a 12.x V also doesn't mean the battery is healthy. Factors such as other accessories running at the time of measurement, ACC circuit resistance and even voltmeter accuracy won't give you a proper reading. And even if everything is working ideally, it won't account for the real condition of the battery.

I agree that the car battery is vital to a vehicle's operation. However, it is not critical that it can cause an accident or pose a danger to the vehicle's occupants if it suddenly goes flat. The car will keep going using it's own electrical power plant. As earlier stated, having it tested during the vehicle's PMS is more than enough precaution so it doesn't happen.

On the other hand, a fault in the charging system WILL eventually cause you to stall in the middle of the road or highway.... that's why it gets its own warning light. As soon as it lights up, you only have anywhere between several minutes to around an hour running on battery reserve, depending on how many accessories you have running (ie. Headlights, A/C, radio, etc.). It is basically just enough to look for a repair shop or a place to park safely to address the problem.

If you notice, most of the idiot lamps often translates to vehicle self-preservation and occupant safety.

Car manufacturers have tried putting oil replacement reminders based on mileage and engine operating time. But even if the feature was developed by the brightest minds, there's still tons of rants and complaints online about oil sludge forming even if the car's oil-change reminder hasn't lit up or is still indicating way below 100% oil life.

Tip: Don't rely too much on instrumentation and use it as an excuse to do a proper PMS.