MattyMac1 wrote:
I remember in the ARMY we use to use glow plugs and block heaters in the winter months even in So Carolina where I was stationed. I'm not sure if they are really for gas fuel injected vehicles? Warm is always better than cold though for combustion chambers though..
Starting diesel engines during cold weather can be frustrating if engines are not properly prepared for lower temperatures. Batteries that are weak may not crank the starter motor fast enough or long enough to start a cold engine. As the temperature goes down, so does battery capacity. A battery that has all of its power available at 80 degrees F will have only about 46% available power at 0 degrees F. Plus, the engine will be 2.5 times harder to start at 0 degrees due to thicker oil and resistance to movement of internal moving parts. In effect, an engine is about five times harder to start at 0 degrees F than at 80 degrees F. Test weak or suspicious batteries under load before cold weather to help eliminate potential problems during busy times. If batteries need replacement, always replace with a battery equal to or more powerful than the original battery. Accessories such as radios, air conditioners, heaters and other high amperage devices put extra strain on batteries. Turn all of these devices off while the starter motor is in use.
in electronics class i was taught a car battery @ -10c (14f) was at 50% power and for every 1 degree celcius drop it loses 10% of its remaining power (not 10% of its total rated power, but 10% of the remaining 50% and so on) though this was many years ago and batteries have gotten better since.
as for the "battery equal to or more powerful than the original battery" i was also taught that a battery rated higher than original would put a lot more strain on the alternator and do more harm than good, especially during colder months. i'd never go with a larger battery myself, there is no need if a block heater is used or if you live in a really cold area then a battery warmer/block heater is the best bet.