Will be taking my 08 535i off the road for 4 to 5 months during the New England winter, should I disconnect the battery and use a tender or leave it connected and use a tender?

 

You accomplish the same thing either or.

 

I store my E90 for the winter/Store my E61 for the summers. I usually pull the batteries out of the car(and inside) and hook a 1.5A charger on to them every now and then just to make sure they are full.

 

I store mine for 3 months and either add an extra battery in parallel to the connected battery or put a tender on the connected battery. No hassle start after 3-4 mos and no resetting of clock etc., either way.

 

Thanks for the feedback, i might just disconnect the negative leave it in the car and put a float charge on it.

 

If you are willing to do that, why not leave the battery connected and put a float charge via the "booster" terminals in the engine compartment?

 

Any recommendations on a good float charger

 

Regarding any recommendations on a good float charger...

I have a Noco Genius 7200 that is powerful.

Next:

Knowing how our modules on the e60 are so hungry for electric power and want to energized, why remove the battery from the car.

Doesn't that add a layer of module problems when the modules do not have power to them for many months?

 

Thanks Scott, good point

 

I also use the Noco Genius 7200. It's an excellent charger/tender with an AGM option for E60s with that battery type. Truly a set-it-and-forget-it product.