what could be draining my truck battery besides the alternator?

Question

I bought a new battery and a wk later it was completely drained after truck not being started for 2 days, after recharging battery and starting vehicle, battery was disconnected and it continued to run.

Answer 1

The starter, or any short in the system could drain it in 2 days

Answer 2

Hmm, charge battery up and then remove the positive wire. Now put a 21watt bulb in series between the battery terminal and the positive wire.

If the bulb is out - there is no great current draw going on - which either means what WAS draining the battery is now switched off OR means that the battery - although new - is faulty and is already self-discharging inside. Unusual.

If the bulb is VERY dim but just on, then this would seem reasonable - perhaps an alarm system and/or clock and/or a tiny trcikle for the stereo etc.

If the bulb is about half brightness - or brighter, then you have a more serious drain - about an amp or so which will drain a 40AH battery in just under 2 days. Look for parking light left on, internal light etc. Try pulling fuses until the bulb goes out - it will help you to identify what sort of thing is using the power.

Mark

Answer 3

I have had this problem before with one of my vehicles. I got frustrated because it took a long time to find. The first thing to do is check for corrosion or a bad connection on your chassis grounds that go to your engine. If your car turns over fine then your solenoid shouldn't be bad. The next thing I would check is the wiring between the battery and the alternator. Some car makers install a fusible link in the wiring to protect components from power surges and etc. Sometimes they are in the wire itself so examine them carefully. If the wire isn't conducting power on one end then that is what it is. If your car is conducting juice then I would check your ignition switch circuit because I know of people that have had shorted switches and guages that draw every bit of juice out of the battery in a short amount of time. I don't know how new your vehicle is but I would check the fault codes. Sometimes they can cause a vehicle to run in limp mode which would explain why your car doesn't want to stay cranked during idling. Check your fuse panel and make sure the alt fuse is good(if equipped). Last but not least check your interior lights like your dome light, glove box light, trunk light and etc. I have had bad door switches that were shorted and drew the battery down. Another thought did you put the correct alternator back in? Sometimes parts stores mess up and give you a part that looks like it is right but isn't. You might not have a high enough amp alternator to run you system. Good luck.

Answer 4

Tricky question with an answer to be determined by a good electrical system mechanic who has the proper equipment. I wouldn't go that route unless I had 1 or more failures...there's just too many possible causes besides a hidden electrical drain.

Heat, cold and IMPROPER storage affect batteries [even new ones at the store!] Owners leave doors ajar, lights on, have kids play with radios, windows cigarette lighters etc and expect the battery to work -- ha!

It's WINTER, so WARM UP your car and thus recharge your battery before you start out. You may have poor habits. Also, don't let others play with elec
gadgets and don't jump start others. Treat your battery like your life depends on it working in the Winter [someday it MAY].

Answer 5

I see it continues to run even with the battery disconnected. It shouldn't. That's the key to it. You've got a fault that needs an auto-electrician to sort for you.

Answer 6

Maybe you are using heavy accesories like fog lamps, heavy hydraulic lifts or maybe any other electronic equipment which drains out the battery too fast before it gets regenerated. Be careful girl...

Answer 7

something staying on all the time,the starter can drain the battery also.