Any problem with using a Battery Tender on my 1.8 FI? I'm always leary about frying something with these old FI systems. Thanks.

I have used a Battery Tender on a 74 2.0 FI for years. Not an issue at all and car starts on the first crank every time it is taken out.

I always use my battery tender

In conjunction with the battery quick disconnect switch

Very inexpensive and may just prevent the batt from draining down in the 1st place

Dumb question.....I have one of the battery tenders that plug into the lighter from when I had my 964. Can it be used on my '74 914?

Spend the money and buy a smart charger.
Click to view attachment

Yes if the lighter socket is the same size.

And that Porsche one is no NLA so someone will probably pay too much money for it because it says Porsche. Better ones are available.

It's just 12v dc, it doesn't discriminate. Akin to asking if you could swap batteries.

Great. Thanks for the info.

Only if you leave the key in the on position while using it. The lighter on a 914 is switched off when the key is off.

delete

You are definitely missing something.

It's not a closed loop. It's 12v going into the system from an external source.

Yeah I had brain fade that's why I deleted my post before anyone else saw how stupid I was......

For maintaining your charge get a Battery Butler. They work great, recommended by the local PCA tech dude and cost less than $20. I have 4 of them, two for cars, one for tractor, and other for generator battery. They are cheap and mine have going for years.

http://www.lectriclimited.com/battery-butler.htm

If you have an Optima battery, keep this in mind:

• Float Charge:
  13.2 to 13.8 volts, one amp maximum current, time indefinite (at lower voltage).
  Strictly adhere to all limits.

A battery charger like the Battery Tender Jr. (0.75 amps) or the Battery Butler above meets the 1 amp max requirement. Many "trickle" chargers do not.

Interesting note if you buy an Odyssey battery the company retailing them were also pushing a genius smart charger.
If you read the the literature that comes with the Odyssey battery, it states that as long as there's no drain on the battery (ie clock, etc.) their battery should never need charging in storage, in fact they recommend against it.
Their recommendation is to disconnect the battery for storage and that's it.

Of course this is for the odyssey, regular batteries I always charge once a month over the winter, but isn't it a gel cell just like a optima?