theiceman

Just happened across this thread and did not have time to read every detail but 250ma is HUGE and I would suspect something is wrong.

Why not each person with this issue get a simple VDM , set it for current measurement, and hok it betwen the battery and main lead ( in series) and see what current draw you get at rest. This will tell you what to expect if everyone does it. Then you will be able to decide ehat is normal.

killsbugsfast

PS - if you live in a thunderstorm prone area, plug your Battery Tender into a surge supressor!

Slow Guy

I posted this in another thread:

A very basic way to see where the draw is coming from is take a blown fuse and insert it one at a time in all the fuse positions and use a DVM set to mA's and track which fuse locations have a draw and how much that draw is. I don't think this will work if the draw is through a relay (depending on the circuit).

You need a blown fuse because you must test amp draw in series and that can be done by putting the test probe tips on the top exposed pins of the blown fuse.

(My DVM probe tips won't fit down in the fuse slots to make a connection which is why I use a blown fuse) Also, per Porsche you run the risk of spreading the pins if you stick probes directly in the fuse socket.

TroyN

Over the years I've seen a lot of posts about the short time that Optimas seem to go before losing charge. I'd suspect that, in most cases, is the problem vs. some power draw. I've my car locked, alarm on, for 4-5 weeks or probably more, sometimes, and though the battery was very low the car still started, didn't lose radio, etc. Non-Optima battery. As noted in the other thread, I use a trickle charger now.

2Many Cars

I've got to agree with TroyN. I have an Aston with a relatively (1 year) new Optima battery and it will go flat in about 2-3 weeks of non use. The old lead acid it replaced would easily last more than a month when it was new. I have twice taken the Optima back to be tested and it was judged to be normal. Also, if you let the Optima go almost completely dead it takes a heck of a jump to get the car going and my basic 10 amp charger won't recharge it. If I keep a battery tender on the Optima I have no problems. I like the Optima but have decided the almost constant use of a battery tender is a price of ownership if the car isn't driven regularly.

killsbugsfast

From Optima's website:

34 & 34R - 34/78 - 6V - 25 & 35 - 75/25
These batteries are designed for engine starting applications. They are NOT recommended or warranted for use in deep cycle applications.


Certain versions of our vehicles appear to have a current draw that is capable of discharging a battery over a couple/few weeks. ( I will measure mine this weekend) I belive this can be equated to a "deep cycle application."

A deep cycle battery is designed to be deeply discharged over and over again (which generally GREATLY reduces a car batteries life) through the use of thick lead plates. Deep cycle batteries also from what I understand generally do not exhibit "memory" issues.

A deep cycle battery can have two or three times the Reserve Capacity of a car battery, but will deliver one-half or three-quarters the CCAs. In addition, a deep cycle battery can withstand several hundred or more total discharge/recharge cycles, while a car battery is not designed to be totally discharged.

Thus, what I am theorizing is that while the optima's may be able to deliver outstanding CCA's and be extremely vibration resistant, this is at the trade off of also being more sensitive to deep discharges - with optmas "going bad" after only a couple of these deep discharge events - Hence the warranty disclaimer.

993_Pilot

Good Info to know !

JasonAndreas

It's not a coincidence that an Optima with a 35Ah capacity weighs half as much as a lead acid battery with a 70Ah capacity.

16-26mA is what Porsche considers normal.

ecobb993

I learned the hard way that if my trunk lid isn't closed all the way the light stays on. Apparently this is enough of a drain to offset the trickle charger's ability to recharge the battery.

Now I carefully completely shut the lid on the charger wires. I'll bet there's an easy, quick way to disable the trunk light, but I haven't found one.

993_Pilot

Just push the latch closed using a screwdriver (or some other tool) and the light goes off. Just don't forget to pull the latch release again before you try to close the lid.