Can anyone give me some advice on properly float charging an Optima battery? I have a Battery Tender Plus charger which I have used on regular batteries with no problem. When the battery gets fully charged a green light comes on indicating the battery is charged. When I use it on the Optima the green light never comes on and if I check the volatge at the battery with a voltmeter I get 14+ volts and slowly rising while oin charge. Is this right? I disconnected the charger as I did not want to damage the battery.

Is there a specific charger that should be used to maintain the Optima?
Thanks for any advice.

 

You need a specific charger than can handle the gel cell batteries. I use a CTEK one.

http://www.ctek.com/EN-US/Buy-US-Charger.aspx

 

I've been using a Battery Tender on my Red Top for the last 5 years. It starts out yellow, then goes Green and just maintains!
This time of year, I go weeks before I start the Porsche, and don't have any problem.

 

+1 on the CTEK.

Battery Tender does an OK job of maintaining them. That's what I use on my 6 volt Red Top in my 356, because I've never seen a 6 volt ctek charger. However, the Optima batteries like to be charged to a slightly higher voltage. The ctek has an "Optima battery mode" that will do this for the battery. For optimum life from your Optima's, use the ctek. I use one in my 911T.



Phil

 

I use a Battery Tender Plus on mine all the time. No problems. Red light, later blinking green light, then finally solid green light.

 

I use the model sold by Griots Garage, and it seems to operate normally via the cigarette lighter connection.

Brian

 

Ok - I left the Tender Plus on it all night and it finally did it. It looks like it gets the battery up to 14.5 volts before it gets the green light. It does look like the CTEK might be a better charger though as it puts out 2 amps, as Optima recommends, rather than 1.25 amps like the Tender Plus does. I guess I may have to get a CTEK although the Tender does work - looks like the CTEK is quite a bit cheaper than the Tender Plus too! Thanks!

 

http://www.amplepower.com/gel/gel.pdf

 

FWIW,...Optima's are not gel cell batteries; they are AGM (absorbed glass mat) batteries. These have circular cells filled with acid and water, but they are totally sealed.

CTEK chargers have an AGM mode that charges these without damage.

 

That's what I meant.