I understand it is allowing a wet cell battery to become completely discharged that kills them. One of the reasons a battery tender is so wise.

E.

95 RK
07 RKC. (The Wife's)
09 RKC

 

I've been using a Battery Tender Junior on my 2005 KTM dirt bike for 5-1/2 years, a battery normally replace every two years. The green Tender "Charged" light still illiminates within two seconds after hooking it up.

I just rotate the Tender to various idle vehicle batteries throughout the year, it seems to REALLY extend their lives.

Just my 2 cents, but I fully endorse the Battery Tender's worth in extending battery life,

 

My first battery on my 04flhtc lasted 3 and 1/2 yrs before going completely dead,no sign,shorted within .I use a battery tender regularly.I know this was the exception ,but I got stuck in another state and had to trailer home.I now change my battery every 3 yrs for pc of mind.

 

I have gone through a battery every 2 years with my old bike 1990 FLHTCU but did not use a tender.
Put a AMG in and started using a tender if the bike sat for more than a week and never had a problem again. Once you get a good battery and keep them charged you should have no problem.

 

27 months and over 50,000 miles and still going strong. Never been on a tender and used almost daily,

 

04 ultra has original battery and it seems to be fine. I am thinking about replacing it though before I take the next long trip. I'd hate to have it go bad when I'm 1000 miles from home. 03 Dyna has original battery and it is fine too. Since I only use that bike for local rides, I will not replace that battery until it shows signs of going south. 06 sportster has original battery and it is fine. All the bikes are on tenders for the winter months.

 

I just replaced the battery on my 06 street glide and that was because I drained the battery completely. I replaced it with a DEKA EXT30L for $60 cheaper than the HD battery (they make the HD battery).

 

05 Ultra original tender all the time. Noticed it cranks a little slow when hot. Taking longer to come up to full charge. After full charge disconnected charger waited 1 hour and it was 12.6 manual says it should be 12.8 to load test it. Will replace it this winter.

 

On one bike eleven years, but a recent one on my Glide only just two! Both had battery minders on them. One on my wife's bike lasted only 6 months before turning its toes up. So there is no certainty. They are probably the most unpredictable part of a bike, so look after it, but be prepared to dump it as soon as it starts giving problems.

 

+1 on the battery tender 24/7. The mechanic at the dealer actually suggested I use it anytime the bike is in my garage parked, not just winter storage. My battery is going on 5 years old and still gets a strong meter reading. The mechanic said his last battery lasted him 8 years.