Battery tender always in charge (not float) mode

I was told by them to plug the unit to the car for about a min. before plugging it into the wall outlet. That might help....

 

Some time ago a person from England had a similar problem but I can't remember what he had for a charger.

However, there was some discussion of a fuse replacement which when changed cured his problem.

Maybe that's the case here?

 

I am inclined to think the battery is bad. Have you had a load test done on it? You can take the car to any Schuck's or Autozone and they will perform this test for free. But before going, I would remove your spare tire and battery cover....this will speed up the process while at the store (they will bring the machine out to your car)>

 

My experience with an Optima is that they don't come back well from going flat. The trickle charger (mine's a Schumacher) just won't cut it.

If I let the car sit more than two weeks, the Schumacher takes a couple of days to bring it back. But then, I have a battery hog recovery system in mine. (80mA drain when off).

The once or twice my Optima went flat, the recovery was odd: After four hours on a full (10A) charger, it still was low voltage. After sitting (disconnected from car) for a week, another four hours on the 10A charger brought it back. After that, the Schumacher can keep it maintained.

If you're connecting to the cigarette lighter, check that the lighter fuse (F4 15A) hasn't blown. That same fuse runs your hazard (4way) lights, parking lights, and power antenna (via the original sw). If that fuse is gone, you're not charging, and the charger will never detect enough voltage to go into float mode - because the connection is open. Same as if you're unplugged from the car.

 

I had a similar problem with my battery/battery charger. I suspect that the battery went totally flat when the car was serviced, this would damage the battery and it will never achieve full charge even though it has enough charge to start the car.

You metioned that the charger works OK on other batteries so the only thing left is the battery in the 328. Have you tried charging the battery when it is not connected to the car? .

 

How are you connecting to the battery? Electrical bolt connection, alligator clips, or lighter plug?

 

Ron,

The only thing I would do is plug it into the car and let it sit unplugged from the wall for 10+ min. Then I would plug it into the wall and see if it starts charging.

If you have a multimeter you can check for 12 volts at the connector that you show in your picture to make sure the wire isn't cut.

 

It is a LOT easier to just wire up with a cigarette lighter plug from Radio Shack...add about 8 feet of lamp cord too, so you can keep the charger outside the car. Then you don't have to open the hood each time.

 

Cig lighter plug doesn't always make a good connection.

 

Usually only if you have a loose fitting or bad cigarette adapter plug (get a good one). Also, your battery tender will always give you a confirmation light that you have continuity. I've never had a problem in my previous 328 or current 355 or BMW...although my dealer installed an onboard charger in my 355 shortly after I purchased it, so I am back to doing it by opening the hood again...

 

Hey gang,

I have a 1.5 amp auto tender on my "lead acid" battery in Rachel. If I change to an Optima battery, I'm not sure if the two different battery technologies would be compatible with the same tender.

I'm sure this question will soon be answered - and will probably end much confusion and "tending problems".

Cheers, Hank

 

According to the Optima website, using a battery tender is fine.

"What kind of charger do I need for an Optima?
Can OPTIMA batteries be charged with a solar charger or trickle charger?

Optima batteries do not require any special type of charger.
If your Optima battery will sit unused for extended periods of time, a maintenance charger can be used to keep it fully charged. (Sitting for extended periods in a discharged state will degrade the performance and shorten the life of any battery.)"

The bigger issue seems to be that Optima batteries manufactured in the past year or two, are not holding up like they have in the past. They seem to fail with regularity, especially so if deeply discharged. It may be better to stick with a "regular" type lead acid battery. The top rated 34/78 size (which fits most Ferraris that came with a size group 34R) is from Wal Mart, according to the latest Consumer's Reports.

 

I'm still using the lighter socket, but I'd like to hook up directly to the battery so I can pull the battery ground disconnect (by the l/f headlamp) and still hook the battery itself to a tender. (Next time the car is on the lift so I can route wires.)

But I'd use an inline fuse between the battery and the connector. A battery can supply huge amounts of current -- enough to turn wires into glow plugs. I took a chunk out of a wrench learning (on the Alfa) to connect the ground terminal last. (The wrench brushed the chassis while tightening the plus lead. With ground already hooked to the frame, ...)

That sounds like you have an excess load from the car. If you have a multimeter with a 10A position, you might want to pull a battery connector and see how much current your car is drawing when off.

With that power hog recovery system, mine draws 80mA. If I leave a door open (interior lights on), my Schumacher trickle charger will return to orange (charge mode) before too long. With the doors closed (and the sterero amp off), it goes back to green (maintenance mode).

If your car is drawing more than a tenth of an amp when off, you likely have an excess load somewhere. On some cars, I'd look for a glovebox or trunk lamp alway on, but the 328 makes clever use of exterior lighting to do he job without extra bulbs. On a Ferrari, it's often an aftermarket part (like a radar detector or stereo amp), which can be tough to track down, as they tend to be poorly documented.

 

Happy to "try and" help......

I own three of these for my cars all connected diff. ways. I think the way you have it direct connected it is the best. But, you need to test your cable to rule out that as a problem.

I have personally had to do what I suggested to you to get the trickle charger to flow in the correct direction.

 

Just close the door on the cord....it has a thick rubber gasket, and a 18ga wire is more than thin enough to be closed on, without pinching....I have been doing it for years now...cable/wire looks fine, no perceptible damage or crushing.

 

Ron, if you are getting a charging indication, then it is connected right...I am starting to suspect you have some sort of constant draw on your battery which is preventing it from being fully topped up.

 

I'm glad you brought this anomoly to our attention. A little research found in fact the Optima "..uses a different chemistry for the plates' active paste material, and a slightly stronger acid." So naturally voltage characteristics will vary slightly.

Lead acid technology usage is so prevalent that that manufacturers of charging devices are tuned to these important voltages. I wasn't able to quickly find Optima's charging characteristics but since Optima is so highly acclaimed I feel the need to learn them. Thanks Ron for the head's up (incidently, I'm an hour north of you - RU w/HP?)

 

So, you know that there is a leakage path in the car somewhere. With the battery fully charged, you can connect it to the car and pull the fuses in blocks of 4 or so and see if the charger goes to float in a reasonable time (of course the little programmer in me says pull half the fuses and use a binary search, but the little mechanic hit him over the head with a torque wrench.) If it's not in the first block, put them back in and move on to the next. When the charger switches to float, start putting the fuses back in one at a time until it goes back to charge mode.

Once you know the circuit, you can isolate the problem and fix it.

Edit: If you have a good voltmeter, you can simply monitor battery voltage while pulling the fuses one at a time. When you pull the fuse on the leaky circuit, the battery voltage will slowly start rising. With a 4 digit meter, 100ths of a volt will start changing immediately. Might take a minute with a 3 digit meter.