Battery tender thoughts

[Baphomet]

I know there are a lot of threads concerning battery tenders, which ones are good, pros and cons, and things like that. Except for extreme conditions, like long term storage or freezing weather conditions there is not much information on when to use one.

I went to the stealership the other day for a couple of spark plugs and the parts dude was really putting a hard sell on me to buy a battery tender. His pitch to me was that EVERY bike should have one and it should be use ANYTIME the bike is not in use. He went on to explain that a bike runs better with a fully charged battery and that the battery last longer, on and on.

I declined buying one because my thoughts are that I ride my bike pretty much every day and usually at least 50 miles most of which are on highways. The weather here is almost never below freezing and the bike is never in storage. However, now I have this haunting idea that maybe I am being close minded and perhaps I SHOULD get a tender. Any thoughts?

[linkin5]

If the bike is ridden every to every other day it would offer no benifits at all except to the seller.

[pres41]

I have one and use it all the time, when not riding of course, I do believe they
make batts last longer, I got 7 years out of my last one.

I use them on my antique cars and even on my lawn tractor.

[BWP 5p]

My garage is heated........the only time I use my tender is when I am not going to be riding for over a week.

I still have the original battery in my 2005. Didin't start "tenderizing" until 2007 though.

I bought the "JR" model....wasn't expensive.

[merc]

I have no answer, as I just put the battery tender connecting wire on yesterday.
My bud has 3 bikes plugged into them all winter and his bikes start in spring as if he used it yesterday.
But his daily is never plugged in during the riding season. He swears by the battery tender but has no need for it if riding all the time.

[Screw Loose Dan]

When I had only one bike and road all the time, year round, I didn't use one at all. Now that I ride less frequently and have a 2nd bike, I use tenders all the time on both of them. My opinion is if you ride at least once a week and usually more, it's probably not worth it. If it's going to sit for a bit, it will definitely help. Our batteries like to be fully charged all the time and will last longer if kept that way.

[MadMax25]

I use one all the time but I find that on rides
that are longer than about 200 miles,
the extension cord gets to be a real pain.

[Bob F]

Lead acid batteries will last their longest when kept fully charged.

Here's my setup:

[Terp84Alum]

I use them on all my powersports (motorcycles, ATVs). I mean for $25 or so, why not. I bought the Battery Tender Juniors. They can be had online for as low as $20. Google it.

[johnnysquire]

The guy was obviously working on commission.

You only need a battery tender for a modern HD (AGM technology) battery if you often let it sit in WARM to HOT weather for more than two or three weeks.

The job of a battery tender is to fight discharge - there's self-discharge inherent in batteries, and there's load discharge. On a parked Harley, the only load is the alarm, if you have one. It's a very small load. Self-discharge is a result of the chemical reactions that make batteries work. Like most reactions, it speeds up with temperature. An AGM battery in 40F won't discharge a noticable amount in a month - maybe 2 or 3%. The same battery in desert hot temps will discharge up to 10% in a month, which still isn't that much. To be safe, a bike in the desert with an alarm could run down its battery enough in a month to make a tender worthwhile.

This may seem counter-intuitive to folks who have had a car battery killed by cold weather. Here's why that has nothing to do with your bike -

1. Car batteries are mostly wet cells - they can self discharge way more than an AGM battery. Even 40% in a month in hot weather.

2. Storage temperature and use temperature are two different things - for the same reason cold temps are good for storage (slowing the chemical reactions), cold temps are BAD for use. The amps put out at 0F are about half what they are at 100F. There's an easy fix, though - warm up the battery. A trouble light put under your bike cover for a while will raise the temp enough to make up for the coldest day you're willing to ride.

Bottom line - put a tender on your classic car wet cell battery, and on your snowmobile battery. Don't bother with the Harley.