Have a R1150GS that keep connected to Battery Tender when it is in garage. Just bought a KTM 450 EXC and want to connect to BT when it is in garage. Do I need another BT so that one is connected to each bike, or can I switch connections between bikes on a "scheduled" basis? What would be a good schedule? (Before someone responds "why spend $$,$$$ on bikes and worry about ~$50 on a BT?", I can afford another BT) Thanks.
I had 5 bikes that had batteries at one time and 2 BTs. I would rotate them once a week but they rarely needed it for more than 30 mins. Now I only have 2 bikes, 950 and 450 and I put a BT on the 450 a week or 2 before I ride it and it still has a full charge. I don't put one on the 950 b/c I ride it a lot more.
I had two Schumacher float chargers ("Battery Tender" is just one specific brand of float charger) die in a power surge recently. I have two left and am rotating them among the four batteries I'm maintaining.
Battery Tender makes a couple of multiple chargers. For the price per bike though it's less expensive to buy a BT Jr. or something for each bike, which is what I've done.
A battery does not need to be on a tender constantly. It just needs to be kept at a reasonable level of charge -- i.e. not be left sitting around in a discharged state. The self dischargerate of a lead-acid battery depends on its construction and ranges from a low of 1-2% per month (for an an AGM battery Lead-Calcium plates in goodition) to as much as 1% per day for an old-school flooded battery in poor condition. So even in the worst case, rotating the tender between the bikes once a week will keep the batteries at or above a 93% state of charge, which is fine. -Uwe-
I use a harbor freight tender/float charger on my xr650l, worked great this past winter here in WI. I think they are on sale right now for $4.99. I changed the allagator clips to a Tamiya type battery connector and wired a tail directly off the battery. Total cost of maybe $8. The tail is wired into the tool kit bag. Left the battery in the bike over the winter, started every time I wanted it to.
I spoke with a guy who runs a local discount battery store (batteries are their entire business). He was very much against leaving the automated float chargers on a battery. He said that none of them were "smart" enough to avoid overcharging a battery as it ages and starts taking less peak voltage. He recommended putting the charger on the bike once every couple of weeks for 4 or 5 hours. I guess that some of the charger manufacturers would argue the point, and I've heard multiple folks on the forums say they leave them hooked up all the time and it really helps the longevity of their battery, but, I guess the option of hooking it up on occasion for a few hours is probably a pretty safe one, too.
If the amp output is too high it will eventually "boil" off some liquid, car battery tenders are generally way to large. The one I purchased puts out a very low current. My stator charges the battery at a much faster rate. I should also note that in warmer seasons I do not attach it after every ride. I ride enough in the summer months that a tender is not needed. Wisconsin is very cold in winter and discharge rates seem to speed up in the cold. I have had batteries freeze solid in my garage.
