QUOTE(alxdc @ Mar 14 2012, 10:15 AM)
the weird thing is. i dunno why honda 12v battery life spend is only 2 years. my city 12v battery have to change every 1.5 or 2 years (could it be the alternator problem?)....where by my other car kelisa battery lasted me 4 years before changing....
does insight comes with alternator? cant remember whether i saw it or not....
Lead acid battery is used in car because it can stands many cycle of charge (when engine runs) and discharge (when you start vehicle or use 12V power without running engine e.g. alarm and door locks or even when you left the car not being driven for too long i.e. self-discharge).
However, there is a shortcoming of lead acid battery i.e. it cannot be left over-discharged or being in discharged state for too long period of time. This will lead to a phenomenon call sulfation or formation of lead sulfate in the battery which is irreversable and reducing the ability to accept and store charge thus reducing the battery capacity.
Based on this, there are some steps that one could try to practice to prolong the lifespan of your car 12V battery:
1) Try your best not to use the battery when the engine is not running e.g. leaving the car door open for very long which turns on the room lights, turing on radio or headlights without engine running, letting your kids play with the power windows etc.
2) While waiting to pick up people, whenever it is possible and safe, do not leave the headlights on even if the engine is running. Apart from putting stress to alternator, the headlight assembly will heat up, causing lens to turn yellowish or fade faster.
3) Do not always full blast your air cond blower. If you get into a car that was parked for too long under hot sun, open all windows when start driving to allow hot air to escape will be a better solution.
4) If you install any aftermarket audio system, rever camera, alarm or lighting, make sure the wiring are donw properly, does not create any shorts and unnecessary circuits are turned off together with ignition to prevent power drain when the car is parked.
5) Avoid short trips (e.g. less than 3 minutes) engine start and stop. Starter motor draws a lot of power and a 3 minutes trip may not be long enough for the alternator to recharge back the power consumed (especially if it is a night driving with headlights, aircond and audio system full blast).
People may ask, when my car is running, my alternator is on and my battery would be recharged so why I have to worry of keeping 12v accessories turned off to save power? The alternator for smaller cc car (usually those 1500 and below) are designed not to load the combustion engine too much in order for the engine to have more power to move the car and maintain the car's high fuel efficiency. In order to maintain the load to be small, the alternator produces lesser power. Usually designer calculated the power output to be slight over the regular consumption of all the 12V accessories under normal use (daytime could be hotter so aircond use more but headlight off, night time headlight on but cooler weather so air cond blower not at high speed). The extra from the slightly over output of the alternator is used to top up the 12v battery depleted by engine starter, accessories usage during stop e.g. alarm and also due to self discharge (normally between 3 to 20% a month depending on quality and size of battery).
Based on the above, if your trip is too short, or you have big amplifiers blasting away with air cond at full speed and headlights on most of the time, chances are your alternator output are just sufficient for accessories or even worst, at deficit, thus either not charging or instead actually draining your 12v battery.
To maintain good lifespan of a lead acid battery, it is normally not recommended to allow the battery to be discharged more than 75% of its capacity. The more it get discharged, the more sulfation would happen and the lower the battery capacity. When batery capacity becomes low, there is more chance you going to discharge it more, thus the effect is exponential when near the end of the battery life. In order to save weight, modern small CC car uses smaller battery, thus smaller capacity and higher chance to get badly discharged more than bigger batteries.
Sideline a bit, Insight does not have a regular alternator and power steering that are driven by belt by the combustion engine, that's why even when the engine is just 1300 cc, it felt so light. Insight does have power steering, but it is driven by electric motor. The only belt driven subsystem in Insight is the air cond compressor.
This post has been edited by cbinn: Mar 14 2012, 11:09 AM