CTEK vs. Diehard 71219 Battery Tender

The Diehard 71219 includes the cigarette lighter adaptor, and is currently on sale for $19. The CTEK , which has a great reputation, costs about $60 if you shop it hard, and the cigarette lighter adaptor is about $10 more. So, what's the difference between the two and to the extent there are differences, is the CTEK worth it?

Great question and I can hardly wait for someone to answer. I've used the Diehard without the cigarette lighter adapter for about 8 years and have never had a problem with it or it's performance. I've been very confused by those willing to spend significantly more money for other brands.

My Mercedes ML350 (2007) sat for a week and when my wife went to start it yesterday found it to be dead, dead, dead. Notably, it has a reasonably new battery in it (less than a year old). I went out and bought the Diehard 71219 and hooked it up directly to the battery , but after a few minutes the yellow charging light started to flash, which is not covered in the owners manual. I tried it again a couple of times with the same result. After that I tried jump starting the car off my Cayman , and couldn't even get a door light to come on, let alone the starter to turn over. Any idea what the flashing yellow light might be indicating? My best guess is that the battery is so dead the unit can't charge it. This, of course, raises the question as to why it got that way in only eight days. It's last gasp, according to my wife, was to raise the electronic rear door, but once up there wasn't enough juice to lower it. Any thoughts?

Don't know if it applies to the Diehard, but on my Braille charger, the flashing yellow indicates "testing" the battery, while steady yellow indicates charging. It usually flashes for a minute or so, and then begins charging. When my Cayman battery finally gave up the ghost, it just sat there for a few hours flashing yellow, indicating I guess, that the battery was really dead and wouldn't take a charge.

I suspect you are right about what the flashing yellow light indicates, although it irritates me that the owners manual is silent on this. As to the battery being too dead to charge, that also makes some sense given that even with jumper cables I could not get any power to the interior lights. A call will soon go to the MB roadside assistance folks. I should have an answer tomorrow. Again, though, still interested in the Diehard vs. CTEK question posed originally.

I have the CTEX Multi 7002 model. I purchased from Velocity Motorcars with Cigarette Adapter after shopping on Amazon . I forget the price but I think it was around $70. This charger can read the state that your battery is in and applied the appropriate charges to get it back to full state. It takes a four step path with the maintenance charge (step four) being a pulse charge to keep it tip top. It also has a RECOND mode for a battery that has been severely discharged. I feel it is the best of the maintenance and can double as a full charger. It can be attached for months to keep the battery in shape. Cheaper chargers go about their business "mindlessly" without the analysis neccessary for a proper charge.

For what it's worth, I just bought a CTEK 3300 on line with the cigarette lighter adaptor for about $59. The Diehard will be going back to Sears. My thinking, right or wrong, is that the CTEK has the better reputation and likely reliability in terms of not boiling the battery . Indeed, it is my understanding that they are the branded manufacturer for not only Porsche but a number of other higher end car lines, and probably for that reason alone. While the Diehard is certainly a good value at $19 inclusive of the adaptor, my worry is that a system failure could lead to a ruined battery . And who wants a battery charger named after a movie, anyway?

In re to flashing yellow LED on the Sears Diehard 71219 Battery Charger / Maintainer (aka Schumacher SC-200A), a call to Schumacher tech support reveals that it means the same as the flashing red LED : the charge attempt has failed. I assume that means any attempt at desulphation also failed. The following link is to the Schumacher version of the user manual if anyone cares to read up on it (the yellow LED flashing is NOT mentioned in either Sears' or Schumacher's user manuals): http://www.batterychargers.com/Documents/00-99-000973.pdf