Battery Tender has 750 milliamp chargers. For most cars, that works great. Mine does have a sleep problem. The charger takes over 1 day to recharge the battery to full charge then maintain. I bought a new 4 amp charger/maintainer. In 5 hours or less, it will charge the battery to full. Afterwards, it maintains it. The 4 amp version has selections for 6/12V and AMG/Lithium batteries. Both chargers work great. Depending on how long the X5 is going to be parked, I choose one over the other. Both are available at Lowes.

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'06 X5 3.0i - bought @143,123 miles (12/26/20)