drained battery

i have a 2003 tacoma
over a two wk period the battery slowly drained
having to try a little harder to turn the car over every time i started
the truck until it wouldn't start at all. i got a jump and it was like a had a new battery... for about a day. then over the last wk the process repeated.

so my question is this,
is it the alternator or is the battery just old
(i mean the battery is old but seemed find up until a month ago)

to find this out i'll need to get truck started then disconnect the battery and see if it continues to run, yes?

can i even do that on the tacoma or is there a kill switch that kills the vehicle when the battery is disconnected?

any input on any level is valued

thank you for your time

 

if the battery is old....like 3 or 4 years(i've seen newer ones do it as well).......its probably got some cells that are dead/dying. if its that bad....alternator will over charge the battery trying to compensate. get the battery checked at autozone. also....as hot as its been everywhere...and we dont know what state you are in......the heat will killa battery too.

welcome to tw.

 

x2....get the battery checked first, 6 years is about all you'll get out of them and could be less depending on the number of times you deep discharged it, amount of load (e.g. accessories), and the climate you drive in.

During that 2 week period, were you driving the truck or was it just sitting there? It's possible the alternator is dying and not able to keep the battery charged up.

In theory the car can run off the alternator alone, but I'm not 100% sure. The battery acts as a capacitor too by helping sustain the 12V level during heavy loads. In other words, the alternator may put out 12V under no load, but without the battery, the loads on the alternator may bring the voltage below 12V and the system may not work as expected.

However, one way I've debugged the system it in the past is as follows: With the truck off, unplug the alternator from the battery, measure the voltage of the battery, start the truck for a few minutes then shut it off. Measure the voltage of the battery again...you'll notice that it is lower than it was before because the alternator was disconnected and not charging the battery. Now, plug the alternator back in, start the truck and measure the battery voltage...if the new voltage is higher, this indicates the alternator is charging up the battery and therefore the alternator is probably ok. Finally, shut the truck off again and measure the battery voltage again...did it go up or is it still down? This indicates that the alternator tried to charge the battery, but the battery did not charge up due to old/bad cells, etc.

If you suspect the battery, take it to get tested.

 

you guys are great

thanks!!!!