Dead Battery

I just went through this recently. I used to keep a Battery Tender connected but read that there have been some incidents of fires, so I decided to fully charge the battery, then turn off the battery switch so there would be no drain on the battery. Folks on here said the battery should last for months without any power drains. The only thing was that I believe the previous owner had wired the aftermarket stereo directly to the battery, so in a few weeks the battery was totally dead. I left the Battery Tender on for several days, but never got a green light to indicate a full charge. I decided to order a CTEK trickle charger, as there a lot of positive posts on here about them. The one I bought has a "Recondition" mode on it that can charge up even a very weak battery. Evidently mine was beyond weak and it would not charge it. Evidently there are ways to fool these trickle chargers into charging a very weak battery by connecting the weak battery to a charged battery via jumper cables. The trickle charger will then sense the stronger battery and start trickle charging and bring up the level of the weak battery. If I had a good battery I wouldn't have needed to charge up a dead battery, but I guess it can save you some money if you happen to have a good battery just sitting around. I was able to jump the dead battery and move the car outside so I could then take off the wheel to get at the compartment in front of the right front wheel well (355). I went and got another Optima Redtop, which I had just replaced last year and swapped it out. I now have the CTEK charger on and it is working great. It has a mode for the glass mat (AGM) batteries like the Optima, which is also the mode for cold weather charging (unheated garage here in PA). If I don't plan on driving the car for a day or two, I will keep the trickle charger on it religiously. ANd when I take the car in for service next month, I am going to see if they can rewire the stereo, so that it doesn't draw directly from the battery. Battery tender chargers have a good reputation, but the CTEKs seem to be more sophisticated, with additional charging modes.

 

I have used Interstate battery tenders on all my classic Ferrari, Porsche and 6 motorcycles for decades which has resulted in battery life of 10-15 years for them all with no issues.

 

I have 3 chargers. For serious cases, I pull out the 6amp chargers and let it rip. Then I back it down to 2amp. I find the trickle charger works most of the time.

 

Don't mess around and simply get a new battery. These cars suffer from various electrical issues if the battery isn't 100%. If your battery has been drained to such a low level you are really better replacing it.

I'd get yourself a decent CTEK unit and get someone to check the mains power is still on when you are away for such a long period next time. Also remember to let the car relearn when you replace the battery.

 

If battery is older than three years, get a new battery. If younger, 'probably' get a new battery. AGL is the way to go.

 

I have had very good luck with CTEK chargers. Remember that the newer chargers will not start charging unless the battery voltage is above 11.4 volts or some voltage like that. Some of the models have a "supply" setting that will charge a completely dead bat. Everything I have read says batteries are damaged once they are completely discharged. During the winter I connect the charger once every 3-4 wks. remember that every time you open the car door the computers wake up and it takes 40 minutes for them to sleep. CTEK has a 8 ft extension cable so the charger can be connected without opening the door (lower the window one inch so I notice the charger is attached before driving). I have heard of chargers failing so I unplug from the car and the wall. The 360 front trunk must be closed and latched for the computers to sleep.....that cost me a battery and 2 months to find. Normal draw is only 35ma once everything sleeps. FWIW.

Jeff Pintler
89 348tb, 86tr, 99 360 3-pedal, S-160 bobcat

 

AGM (absorbed glass mat) is the way to go. Sorry for my mistake above. Odessey used to be considered the best, but their quality seems to have slipped. You'll have to do your own homework on brands.

 

Are cars still delivering with the FIAMM junk?

For a little while, we started putting in Interstates at PDI (damning the possible penalty) to stave off the new dead Ferrari complaints.