Can you cook a battery with a tender if you leave it on for 6 to 8 weeks

 

Should not be an issue as long as it is a good one. I leave my Optima tender on all winter and have since 2006!

 

A "tender" will not overcharge / cook your battery. You can leave it on without worry. My Battery Tender+ is on my car whenever it goes in the garage. It will only charge to a certain level and then maintain that charge by cycling back on as voltage drops to a predetermined level. A trickle charger that continually charges and never stops will eventually cause damage, so don't leave one of those on for extended periods.

 

Yes, with the wrong tender.

Hence the cheap trickle charger from harbor freight have too high of a standing voltage and will boil a lead type battery if left on too long, and since they are not designed for a AGM, will kill them as well.

The Black and Decker maintainer is not bad, but since it lacks a desulfator cycle like most other the lower priced units, you may not get the life out a battery that you would with a Ctek 3300.

To be blunt, just pick up a Ctek 3300, and make sure to put it on the car if you are not going to drive the car for a week or more. The little more money you spend on the 3300 up front, will be a lot cheaper than the money you speed on another tender first, then buy it afterwards. Plus with the desulfator cycle that the 3300 has, will help the battery to last longer as well .

To add, I have both a Black and Decker maintainer that I use it on the truck or 6v batteries when I'm away, and a Cteck 3300 on the vet. I needed something for the vet before I fly out on a extended trip, so pick the B&D up to throw on the vet first from walmart for under $20, then switched over to the Cteck 3300 on the vent when I go back and it was i the mail box waiting for me.


The B&D is both 6v and 12 V, but does not work on AGM batteries.
The Cteck 3300 is 12v only, but does work on AGM batteriess, as well as lead cell batteries.

http://www.walmart.com/ip/21721663?w...055512&veh=sem


As for the Ctek 3300, check around on the site, since there are vendors here that have the accessory kits with them for a reasonable price. On mine, I have the lead connectors off the battery that plug into the extension cord, then into the charger so I can leave the 3300 screwed on the wall(read just pop the hood, plug it in, then lower the hood back down without latching it).





If you want to go high tech with a mag type quick plug so you don't have to pop the hood, that is a option as well.


http://www.nakidparts.com/id127.html

 

Before I retired from Optima, we tested a bunch of maintainers and chargers. Like Dano said, you want a pulse type unit. I had a Pulse Tech on before Optima came out with a maintainer and after 5 years, the yellow 35 Optima tested just like a new battery.

 

What about the battery tender Jr high efficiency?
Any good? Normal? Save and buy ctek? Not good?

 

Can't opine about the Battery Tender Jr. but I have two Battery Tender+ units (one on each vehicle in my garage) which have performed flawlessly for years. I would expect the Jr. model to do equally fine.

 

Not bad, but if you don't have one, I would buy the Ctek or Optima. I think the Optima one is more user friendly and you can get them at the local Advance stores.

Just my opinion.

 

We do have people on here w. Harbors, Sears, Schumachers, Black/Deckers, etc. and all seem to perform well for years. That said, I am pretty sure my Schumacher died after about 8 years. Maybe that's not long, maybe it's average.

 

We have the Corvette-marked CTEK 3300 and I use it any time we will be home but the car won't be driven for a week, or if doing work (open doors) that will turn on the interior lights.

However, I'm reluctant to leave any electrical equipment On for long periods of time, unless I can check it periodically. There have been occasional posts here about tenders going bad and boiling the battery, and I suppose it might be possible to do even more damage than that.

When we go on vacation for weeks in the Corvette, I just disconnect the battery in the tin cars.

 

This is what worries me the most. Regardless of what I get, my car is gonna sit for six months or maybe seven. Undriven and untouched. My wife is clueless in regards with car things. She refuses to check on my car while I'm away. Besides making sure no one stole it. I'm guessing to be extra safe I could remove the battery and plug it to the tender. If something happens then just battery is damaged. Idk. My last two deployment, I simply unplug negative of the battery and left it in the car. Came back after 7 months, plug and it was all good no issues.

 

Anytime a battery discharges, damage is done. The best defense is a battery tender. A modern tender has a software algorithm that takes the battery through the stages of bulk charge, absorption, and float. To learn more about how a tender works, go to
http://www.batterytender.com/Battery-Basics/ I don't daily drive my 2009. Unless I am out of town with my car, the car sits with the battery tender plus everyday. If you need photos look at my profile on how to connect the positive and negative on a C6 base car with steel frame.