ebill3 said:
Different battery chemistries. Prius is NiMh, LEAF is Li. NiMh have a high rate of self discharge, Li do not.
Do as you wish, but leaving a Li battery at full charge for extended periods is exactly the wrong thing to do.
I'll have to disagree with you again. I also run a business refurbishing laptop computers. Nearly all of these laptops use the 18650 Li-Ion cells in their battery packs. When I get in a shipment of computers, one of the first things I do is charge up all of the batteries and then test them. I test them by running the laptops until they shut off. Then I write down how long they worked. Then I recharge them all. I replace all of the dead batteries with good batteries. Then I put them in the warehouse.
OK, sounds great. The problem is, sometimes a group of computers might sit on a shelf for 6 months. Unfortunately, it happens all of the time due to priorities shifting on different merchandise coming in or being sold. When I finally get those computers off of the shelf, the batteries in all of them will be completely empty. So then I put them back on the chargers for a few hours. Guess what? You can bet that 25% of the batteries will never charge up again. Now, these are usually the older batteries. If the battery was a brand new battery it will typically recharge even after being discharged for a while. The older ones seem to be a lot more sensitive to that.
I'm actually going through this right now as I've got a bunch of MacBooks that have been on the shelf for 6 months and since this is the holiday season, pretty much everything in storage will be sold by the end of the month. I've spend most of the day going through this group of computers and finding all of the batteries that are dead so I can replace them. Sadly, these batteries were good 6 months ago when they were tested and were able to power the computer for at least 2 hours (that is my standard) but now they are dead as a doornail.
I'm trying to start a new system for 2012 where I will make it a point to charge up the batteries on stored laptops at least once every 30 days. That should save some money and eliminate the problem.