rjwoerheide

I have the Deltran battery tender plus, but the symptoms you describe sound normal. I agree with AORoads.

metroplex

It depends... A smart maintainer tends to go through 3 modes:
Absorption Charge
Trickle Charge
Maintenance Charge

In Absorption mode, the charger tries to raise the battery voltage to 14.4-14.5 VDC, and then switches back down to 13.2-13.6 VDC at a lower current. Finally, it flows back to a maintenance charge of about 12.8 VDC to 13.2 VDC at 20mA to 250 mA.

I have a Battery Tender Waterproof 800 mA smart maintainer for the battery on the 2007 Mustang GT and it provides a steady 25mA of current at ~12.85VDC during maintenance mode (Green LED / CHARGED). I rarely see it switching back and forth unless I am drawing power from the battery.

If your battery is old, it may switch back and forth constantly due to higher parasitic discharging from sulfated plates. If your battery is relatively new, your car may have an added parasitic load (electronics/accessories). Keep radar detectors, cellphone chargers, and other devices disconnected.

metroplex

Good tip. I use some old socks with kitty litter crystals (the ones that absorb moisture and odors) spread throughout the interior and trunk of the GT. It takes away any funky smells that may linger in the interior, along with moisture.

vettnut69

I have the same sears model (71219) which I bought couple of weeks ago and mine did the same thing for the first couple of days and then slowed down a bit.. I have another model on my battery back up sump pump and that constantly goes back and forth and has been doing that for years.

metroplex

I recommend the Battery Tender:
http://batterytender.com/product_inf...01f1ae3acf8dbd
http://batterytender.com/product_inf...01f1ae3acf8dbd
http://batterytender.com/product_inf...01f1ae3acf8dbd

Amazon has better prices. I use the Waterproof, which is a fully encapsulated charger (you can immerse the charger in salt water while it is charging), for my Mustang. I looked at the Schumacher and Sears chargers but you have to make sure they're fully automatic and even then there are different grades of electronics quality. The Battery Tenders are pretty much the best in the market.

Racer86

For those of us that use a Battery tender,,,,,does this make the Corvette a,, "Plug in Hybrid?"

Shylor

I have two Sears Battery Maintainers. They are several years apart in age. The newest one is 2 amp and the older one is a 1.5 amp. The older one would charge a battery from the amber light to green and stay at green, unless the battery power was used and it needed to charge again. Yet the newer model kind of jumps back and forth between green and amber every minute or so. I am told this is a good thing in maintaining the battery. So then why didn't my older unit do this....is it bad or did they change the design, like they did the amps? Sears just puts their name on them but Schumacher is the actual manufacture.

metroplex

That's what my Black and Decker does - it jumps back and forth. Once it dips below 12.6 VDC, it springs to life and brings it up to 14.4 VDC then repeats the cycle. This is worthless IMHO. My Battery Tender Waterproof maintains the battery at 12.8-13.2 VDC at 20mA-200mA. It springs back to life only when there is a big load.

Shylor

All I know is that my older Battery Maintainer (the 1.5 amp), that didn't jump back and forth, ended up with a dead battery twice. So even though it was showing a green light the battery was not charged. It may be that the battery was beyond holding a charge but then I would think the charger wouldn't have shown a steady green light.

metroplex

The Battery Tender is basically the Corvette of battery chargers. If you're not sure about what the charger is doing, it is time to log some data:

Monitor terminal voltage
Monitor current leading into the battery

A $50 Sears AC and DC clamp ammeter w/ digital multimeter functions is a worthy investment. I confirmed that the Battery Tender waterproof IS providing current into the battery when the LED is green. I also confirmed the voltage is maintained at around 12.8-13.2 VDC. At 20mA-200mA, that is enough power to maintain the battery (which is what you want) and prevent sulfation. A charger that totally cuts off when the LED is green doesn't really do much good as it is allowing parasitic drain of the battery until the voltage reaches a pre-established set point.

Amazon just dropped the price on the Battery Tender Waterproof from $40 to $33.99, so I bought another one for my daily driver (when I park it on the weekends):
http://www.amazon.com/Deltran-Batter...6664148&sr=8-1

MYREDZO6

I just bought one of the DieHard 71219 Battery Maintainers and noticed that all 3 lights are blinking very fast. It does this for a short while and then switches back to charging. Have any other owners of this model experienced this and is it normal? The Manual says nothing about it. My Z06 is new (November, 2010) and so is the battery as I had the dealer replace it after it died on the second day of ownership. BTW, it also did the same thing on one of my other cars which I used as a test to make sure it would not blow up the Z06 battery; it didn't so I guess this is normal? Any replies about this sympton will be much appreciated. Thanks.

ncvette_1FUNRIDE

IBTL .............. 2 year old thread.