Battery Tender or Charger?

[Bane]

I recently placed a new battery in my 2001 X5. I still have not isolated whether or not the cause of my battery issues were due to an old battery, parasitic draw or the alternator. I have 2 questions: (1) while I'm still researching whether or not I have parasitic draw is there a good way to keep a charge on my battery if it starts to go down such as a battery charger or tender. And which is the best one or the two. For instance should put it on a charger once a week for a few hours to maintain the charge... (2) when trying to use a multimeter on my battery how do I turn off the tailgate so I can get a proper reading without it knowing I'm doing it. I hope all this makes sense...

[14thbmw]

On the first question, of course either will work but the tender is easier since you can connect it either directly to the charging post and ground under the hood or via a hot cigarette lighter outlet and just leave it alone. The charger usually requires you to turn it on and off or otherwise make sure it isn't overcharging and comes on when needed if the battery is draining. I own both and for the use you described I would use the tender. If the battery was low/drained, I would put it on the charger until fully charged, then switch to the tender.

[Ricky Bobby]

I've always used battery tenders, especially on my motorcycles. They come with pigtails so I can leave connected to the battery post and just "plug it in" when done with a ride.

Depending on whether you need a tender or a charger on your X is dependent upon what kind of parasitic draw you have on the battery. My X5 has a 2 year old battery and never has been charged or tended, and the most I haven't driven it is like 2 weeks without starting and it's been fine, so it never needed it.

[Clockwork]

CTEK 3300 is PERFECT.
amazon.
I just picked up a ctek 7002 as well for my car with two batts in her.
CTEK Battery Chargers - The World's Smarter Battery Charger BMW even uses them but re-brands them with their logo

[upallnight]

Originally Posted by Clockwork

CTEK 3300 is PERFECT.
amazon.
I just picked up a ctek 7002 as well for my car with two batts in her.
CTEK Battery Chargers - The World's Smarter Battery Charger BMW even uses them but re-brands them with their logo

I have the rebranded CTEK for my PORSCHE.



I use a regular Schumacher tender for the BMW