How Long Will a New Battery Last with Bad Alternator
My truck is stranded at Target and I really don't feel like getting it towed. I want to get a new battery anyways since its over 8 years old. If the alternator is bad, can I make it home from a 30 minute highway commute? I know dumb question, I would just rather replace the alternator at home (if that is the problem) than trying to do it in the dark at Target.
Yeah, you should be fine to make it 30 min with a fresh battery.
When installing it, I'd supplement it with a jump from whoever is giving you a ride. In other words put the battery in your truck, connect everything, and hook up a set of jumper cables to another running vehicle while you start it. This will give you a little extra juice to make it home.
While you're driving home, minimize all electrical drain.
No electric windows.
No fiddling with the electric seats.
No headlights in daytime.
The truck's computer and auto transmission use a fair bit of juice just to operate the necessary functions needed to keep the engine running and transmission shifting.
please check both batteries! Diesels needs two fresh units with a working alternator.
Have them load tested, one good battery will be drained by bad battery
have alternator tested as well. Most new alternator will have a lifetime warranty
Cold cranking amps (CCA) is a measurement of the number of amps a battery can deliver at 0 ° F for 30 seconds and not drop below 7.2 volts. So a high CCA battery rating is especially important in starting battery applications, and in cold weather.This measurement is not particularly important in Deep cycle batteries, though it is the most commonly 'known' battery measurement.
CA is cranking amps measured at 32 degrees F. This rating is also called marine cranking amps (MCA). Hot cranking amps (HCA) is seldom used any longer but is measured at 80 ° F.
Reserve Capacity (RC) is a very important rating. This is the number of minutes a fully charged battery at 80 ° F will discharge 25 amps until the battery drops below 10.5 volts.
An amp hour (AH) is a rating usually found on deep cycle batteries. If a battery is rated at 100 amp hours it should deliver 5 amps for 20 hours, 20 amps for 5 hours, etc.
If you have a 50 amp load (600 watt) typical of a diesel with nothing else on... no ac no lights, etc...
You have the minutes battery says... less about 25% based on state of charge and error ....
I've been told that a bad battery will kill an alternator and vice versa. I know that I have had a battery go bad and the alternator went suspiciously soon thereafter a couple of times. Confirmed both were bad with testers, not the replace and hey now it works method. To be on the safe side, you might pull the alternator and have it tested just to see. All the parts shops around here will do it free.