12 volt battery question

So for example, if you have a battery reading 12.6 volts, and a 16 milliamperes draw, is it not abnormal for it to be reading around 12.45 on 3-4 days sitting idle?

It doesn't seem to continue linearly, ie: it seems to stabilize (or I'd like to think so), at that lower number.

 

Yes I think all of that could be considered "normal"......but somewhat marginal after only a few days.
According to the SOC tables, that equates to a loss of 25% capacity and that is a LOT over just a few days.
That is assuming a conventional flooded cell battery. If it's AGM, the prognosis is worse.

The current drain may actually decrease after a few days too.

 

Either way is fine. Pick one.

There is virtually no danger of a new battery going dead in 16 days......IF IT IS FULLY CHARGED TO BEGIN WITH.
That's unless there is some kind of fault with your car of course.

Have you called around to auto parts stores and other Toyota dealers ?
That $125 installation fee is outrageous but the batteries do tend to be kind of expensive.

 

OK I hope that works out for you.
You just seem to be putting a LOT of trust in this guy.
Hope it's not misplaced.
It probably isn't; I tend to be overly cautious. That comes from being burnt too many times.

 

There seems to be many factors. Corrosion, moisture, phantom-drain and self-discharge all play a role, I'm sure.

 

I'd be inclined to get the toyota battery and install myself. But I'd check voltage at the deslership, should be at least 12.6 volt. Then hook it up to a smart charger, let it run to completion. Then clean the posts and cables when doing the swap.

It's pretty easy: disconnect neg cable first, and reconnect it last. All you really need is a 10 mm wrench. And fine sand paper, and/or a post cleaner tool. A 1/4" drive with 10 mm socket can come in handy.

When tightening clamps, I don't have a torque wrench in that range, let alone compact enough. What I do is keep my hand maybe halfway along the wrench handle, and don't use much force.

 

That's normal, especially if you measured not too long after turning the car off (i.e. less than 12 hours). There's something called "surface charge" - after the battery has been charged, there's a little residual charge on the plates of the battery that keeps the voltage elevated. If you put a load on the battery for a few minutes (like by turning on the headlights) or let it sit long enough, the charge will be used up powering the load, or dissipate into the battery (by the same chemical reaction that happens when you charge it), respectively.

So most likely, 12.45V is what your car would read if you got rid of the surface charge before the 3-4 days. And that's a totally normal battery voltage; mine has read ~12.5V since approximately the day I got it, and the battery is still in fine shape (measuring the same 12.5V) 5 years later. And that's including one complete discharge that happened a few months into ownership, which doesn't seem to have had any lasting effects.