I bought one of the small Noco 12 volt battery tenders awhile back when I was not able to drive. Did not end up using it as it always seemed someone else was using my car... Wanted to hook it up today to my Subaru Outback and saw that there are various settings based on if the batt is just an old school 12v, AGM, extra flooded, etal. The factory OEM battery just has CCA on it and a part number. Extensive Googling got me nowhere except that some claim it is flooded. Some say regular and some say AGM. Subaru parts lists I found are no help. I could call the dealer, but I think that is about a 50/50 chance of a correct answer. So, if I hook it up as just a regular 12V will the world end? kris
The lack of such basic info on the battery seems common. It is likely a maintenance free flooded. Charging an AGM with flooded settings could lead a shorter life for the AGM. Sealed batteries like AGM, gel, and maintenance free don't have a way of replacing water from off gassing. Their charge profiles are intended to reduce that off gassing. The maintenance or float charge difference between the types likely won't be an issue. The amperage draw for a full battery will be low. I suspect any potential harm is less than letting the battery sit for extended periods without a maintainer. Not going to apply to your maintainer, but my Outback manual says not to charge the 12V at over 10amps.
My (very limited) understanding, basically from reading in between the lines in my CTEK 4.3 manual, is that the only difference is for certain* AGM's only, the "snowflake" setting is recommended. It's for extreme cold weather, uses slightly higher charging voltage. FWIW, I installed a Optima Yellow Top battery, in September of 2015. With our usage so sporadic, I've had it on the charger more than off, and IIRC for the first few years I didn't use the snowflake setting. It's still going strong. * Pretty sure I saw the expression "spiral-wound" somewhere, like the 6-pack style Optimas, but not finding it at the moment
Hey, all: Thanks for helping bounce the idea around. I needed to clean the Outback as I have to take a passel of people around this weekend. Apparently not everyone enjoys being covered in canine fur and for some reason they believe they ought to be able to see out windows without doggie slobber covering the glass. Anyway, the woefully underpowered Outback battery tends to die if I leave the hatch and doors open while cleaning. This time I just worked turbo mode and did half the cleaning. I then jumped in the car and ran some errands, recharging the battery and finished cleaning when I arrived back home at 8 p.m. We will see if it starts in the morning. LOL! kris
The AGM charging setting won't harm a flooded cell battery, but the flooded cell setting could damage an AGM battery .... that help at all? T1 Terry
My CTEK manual says it’s setting for “certain” AGM batteries is slightly higher charging voltage. I’d take that to mean the regular charging parameters are safe for all, albeit under-performing for those AGM batteries. I’m an electrical dummkopf though…
Unless, the lower voltages lead to more off gassing for the AGM battery. Which it could if means subjecting the battery to the charge voltage for a longer time.
I have at least 3 NOCO battery maintainers, and more of other various brands. I used a Schumacher battery maintainer on my Dodge Ram for over 10 years, and it worked fine. But of all the brands, I like the NOCO the best. It just works better. Other brands fail for various reasons. Some of them turn themselves off, and since they ae usually mounted out of sight, you go to start your vehicle, and the battery is dead. I had a cheap one in my Gen 3 Prius, and the biggest problem was the alligator clips losing connection unexpectedly. I recommend connecting it to your battery with ring terminals.
I connected a trickle charger to the battery of my T-Bird one winter. In the spring, the battery was destroyed, all the electrolyte gone. A battery maintainer is best, because it periodically tests the battery level and gives it a top-off charge as needed.
I'm also a dummkopf, but I'm good at Googling. Lithium batteries can be constructed using banks of 3 or 4 cells, unlike AGM (Absorbent Glass Mat) or FLA (Flooded Lead Acid), which use banks of 6. Most configurations recommend a charge level of 13.8 V, which is probably considered for optimum battery longevity, and will not likely be damaged by overcharging. A lead acid battery responds better to higher charging voltages in colder temperatures, but the type is fairly resilient to varying voltages. The same can be said for AGM.
IIRC the CTEK I have says 14.4 volt and 14.7 volt for the “snowflake”, ostensibly for any battery in extreme cold, or the 6-pack Optimas, all the time.
I use a cheap voltmeter plugged into my lighter socket. I think, due to the Prius's battery management system, the voltage starts out at 14.7 in the morning when it's cool, but drops to 13.6 when the battery gets warm.
