battery tender

[NorthernThrux]

I have a CTEK MXS 5.0 and the instructions state that normal battery program (the car symbol) should be used for Gel batteries. The AGM option is for "AGM batteries lots Optima and Odyssey".

That's why it's good for us to read the manuals. My CTEK MUS 4.3 states for the snowflake program, "Cold Weather Program 14.7/4.3A Use for charging at low Temperatures and for power AGM batteries like Optima and Odyssey". For the car symbol is says "14.4V/4.3 A. Use for WET batteries, Ca/Ca, MF, GEL batteries and many AGM batteries".

So your point is a good one. Which mode?

Currently I have Odyssey PC925s and so I am using the snowflake. Which is correct. But what about the A540/40A ?

The Sonnenschein specs state that it should be charged according to DIN41773 (https://docs.rs-online.com/c6a2/0900766b81270ea4.pdf)

The instructions state that when charging (disconnected from a load) it should be charged with 2.45 Vpc (volts per cell - we have 6 cells = 14.7 V). For float (maintenance) it should be trickle charged at 2.3Vpc (13.8 V).

My CTEK in snowflake mode produces 14.7 V to charge and 13.6 V to maintain. In normal battery mode it produces 14.4 V to charge and 13.6 V to maintain. So no difference for maintenance, but a 0.3 V difference for charging. Matching the Sonnenschein specs to the CTEK specs suggests that snowflake is the correct mode to use. It's not a big deal as the maintenance voltage/current is the same in either mode. It's only the charging and the pulse charging conditions where it gets a bit more voltage in snowflake mode.

Ravi

[gled49]

I have a battery minder that separates flooded, gel and AGM. When I talked to their techs, they said gel batteries have a specific float charge requirements. I suspect the latest maintainers are smart enough to do the job.

[LiveFromNY]

This is why I hang out here. I spend all day as the smart guy in the room then click over here and find out that's demonstrably untrue. I mean, crap, turns out I don't even have a handle on freakin' battery maintainers?

[Jim Breazeale]

I'm partial to Noco chargers I've got a Noco Genius G3500 that I use often on all my cars including my 6V 356s with Optima batteries. It has been flawless for years. I had a couple of Ctec chargers and they were a bit fragile. This was a long time ago and the times may have changed. Can't go wrong with NOCO, though.

Regards

Jim

[NorthernThrux]

There's no real magic Jim. I used NOCO on my motorcycles for years. Worked great and often better priced than CTEK. All the smart chargers do the same thing. They all charge to DIN41773 specs. If they didn't, they'd void the battery warranty. And before somebody tries to tell me that DIN41773 is only for lead acid batteries, I'll also dazzle you with the fact that AGM and Gel batteries are lead-acid batteries. They are called VLRAs or valve-regulated lead acid batteries because the acid is contained in mats or gels, i.e. semi-solid forms that allow arbitrary positioning.

[LiveFromNY]

My opinion of you just went down the tubes..

Quite frankly I'm surprised there was room for any downward movement at all!

[govols!]

Would the Noco work on my Porsche Moll batteries ?? And I need two .. these cars are higher maintance than my 356 !! ...

[govols!]

Looks like Noco makes a two battery maintenance charger. Perfect for our 911’s !! What do you’all think ??

[Jim Breazeale]

Would the Noco work on my Porsche Moll batteries ?? And I need two .. these cars are higher maintance than my 356 !! ...

George

Yes, it would work just fine. You only need one. It will maintain both st the same time.

Regards

Jim

[govols!]

Thanks Mr Breazeale !! Would just one tender to one battery keep both batteries charged ??