captain911

Greetings,

I replaced my battery yesterday that lasted over ten years while attached to an older model Porsche battery tender. I noticed that over the past few days the red light on the tender would not go out, so I figured it was the battery not being charged properly based on its age.

This morning I noticed the red light is still on the battery tender with the new battery installed. Normally the red light shuts off after a few hours.

I have scanned the Rennlist threads and all systems "appear" to be operating properly. (Thanks bcameron59)

- Frunk light switch goes on and off
- Alternator belt tension appears correct
- No noises at all from the car

I will multi-meter the vehicle tonight but was just wondering if the battery tender could be bad?

I want to make sure I do not damage the new battery if I keep it connected to the tender.

Thanks for any input.

Tim

nine9six

Tim,
Not sure if this is applicable...From Battery Tender.

RED LIGHT: When only the red light is on it indicates that the battery is correctly connected and the Battery Tender is charging it. The Battery Tender will deliver its full rated current (approximately 2 amperes) until the green light starts flashing.

captain911

Thanks nine9six.

My tender is the old Porsche one that only has a red light.

P-daddy

I had an older battery tender that would do the same. I just disconnect then reconnect the charger. Usually within an hour or two depending on battery condition and charging rate, the red light would then go out.

captain911

Thanks P-daddy.

That's exactly how this one used to work.

Guess I will be sorting some gremlins.

Foxman

I have two battery tenders, both with just red lights, and one of them acts just the way you describe (while the other charges and then shuts off within a few hours). The red light doesn't stay on forever, and it does cycle on and off, but the light is on for markedly longer periods of time.

captain911

Thanks Foxman.

Here's hoping it is just a glitch in the tender like the one you have and doesn't affect the new battery.

pp000830

If you find your tender to be unreliable one option is to buy and aftermarket charger/tender, cut the plug off an old cigarette lighter phone charger and adapt it to the cord. The nice feature in this is you can have a charger that will charge a dead battery when you accidentally leave a light on and a float charger all in one. I believe my charger is the $30 variety is rated at 2 amps or so and it will allow me to start the car after charging for 2 to 4 hours depending on battery condition. Also most batteries get replaced because owners fail to refill the electrolyte fluid as it evaporates. All liquid filled batteries have cells that can be topped off with distilled water. Even most of the "maintenance free" variety have cell covers that should be pried open and filled.

captain911

Thanks for the input pp000830.

As it turns out, I was getting ready to start sorting the possible issues and the battery tender light went out.

At that point the only thing left to do was go for a "spirited ride".

I assume the new battery may have needed to be charged a little from the tender. Anyway, all appears good now.

Cupcar

FWIW - I have a Ctek Multi 7002 which I believe is very similar or identical to the Porsche branded charger from Porsche now. Charge and float, very nice if you have a small battery and don't drive car every day. I think around $110 if you shop the 'net.

http://smartercharger.com/products/b...multi-us-7002/

captain911

Thanks Cupcar.

Will check that one out if this one starts acting up.

nine9six

If memory serves, Ctek is the OEM for the Porsche tender. I forget which model, but I did post this info when I researched it a couple of months ago...

Ctek also furnishes lesser and upgraded models to that of the Porsche model unit.

FWIW, Id just as soon use a delrin Battery Tender, for less than half the price of the Ctek model being discussed here.

Ive had my Tender for over 10 yrs., and it keeps my car battery lasting 10 yrs!

vincer77

My CTEC shows that it is charging when an interior light is on. Check doors, hood etc..

Rockit

If you bought a Porsche battery like I did make sure the water level is full in each cell. I checked mine brand new from the dealer and they were all very low to the point the led cells was out of the water.

Typically the batteries come 50% charged. It's not uncommon for the tender to do that on a new battery. But it should be 100% after 24hrs, if not the tender could be going. I have 12 tenders of different brands and I've found they last about 15 years...some longer or become unreliable.

For what it's worth I only buy this charger now, if I have to buy one I want it to do everything from float, maintain, bring back a sulfated battery as well as small and large batteries both 12 and 6 volt.

https://www.denniskirk.com/tecmate/o...prd/284005.sku

Cupcar

Actually, the batteries come to the dealer dry and are filled by someone there with electrolyte. If you have one that is not filled it is the fault of where you bought the battery, not Porsche.