Battery Tender question

[challey]

In past winters, I’ve used a Battery Tender Jr to keep my R’s battery up to snuff during the cold weather since I can’t ride every day. The connection as been on a timer, which switches the BT on for about 2 hours, this was always more than enough time for the LED indicator to go from red to green.

A riding buddy recently told me that this is actually a bad practice and that the BT should either be left on all the time OR unplugged from the bike (not just from the outlet). The reason for this he said, is that if it remains connected but not powered, current flows out of the battery and energizes the BT, essentially draining the battery.

Is this hooey or is there anything to it?

Charlie

[NoRRmad]

There are diodes that block backflow of your battery charge, but they don't block it all. Threre is a small leakage, but this is about the same or smaller than the current used by your clock. I don't think you should worry.

My charger (they say,) senses the battery voltage and switches itself on if it falls too low, so I leave it connected all the time.

[gregor]

And, as my earlier post, my local dealer said that I should not leave a battery tender switched on all the time
I used to leave the tender on all the time and have had a good battery life (6 1/2 years). Just nervous about the £140 battery (including fitting) that was installed recently.
My 'current' compromise is to use a weekly timer to connect the tender for a 36hr period, once a week. The green light comes on in a few hours after switch on, but I want to allow for a discharge/charge cycle. Will keep an eye on the behaviour and adjust if needed.

[MikeCam]

While I cannot speak for the British power delivery system, the US version of the Battery Tender brand can be left on all the time (but it is wise to check each 24 hours for shorts, overloads, or other gremlins. The minimum time to leave it on also matters. Simply waiting for the green light is not a full charge for AGM or gel batteries. The charged ions need time to spread uniformly throughout the solid suspension (unlike wet cells). A good rule of thumb is steady green light plus 6 hours.

[Sunbeemer]

There are different kinds of battery tenders, too; in addition to those that can be left on all the time without overcharging the battery vs. those that should be disconnected to prevent doing so, there are different kinds for different types of batteries, and a wet cell charger will actually harm an AGM battery. Diodes in any tender should prevent discharge when off, as previously mentioned.

[rbmitchel]

I'm not real clear about this BT issue. I've had r bikes for almost 5 years, and have never had a battery problem. I ride at least once a week. Won't this weekly ride keep my battery charged, or do I need to hook up on a regular basis?

[challey]

If once a week keeps your battery topped up and you have no problems cranking the bike over, then you probably don't need a BT. During the cold weather months, the snow/ice sometimes conspire to keep me off the bike for 2 weeks or more on occasion. That's long enough to need something to keep the battery charged, hence the BT Jr in my case.

Not wanting to overcharge was the reason I put the BT Jr on a timer. While the manufacturer claims that the circuitry in the BT is supposed to sense full charge and taper things off, I'm sceptical by nature and wanted some more positive assurance. My original question really amounted to asking if I was doing more harm than good using the timer.

Charlie

[lionlady]

The Battery Tender brand charger is designed to be left on/connected for extended periods. It was created so you don't have to worry about wrecking your battery, as the 'regular' kind of charger can do, if left connected/charging for extended periods of time.

Using a timer on a Battery Tender seems redundant. It could be that your source is referring to the old style charger.

We've got one BT for 3 motorcycles. Hubby or I just move the charger from bike to bike to bike, as/if needed.

P

[bmwdave52]

I leave mine on all the time I'm not riding.
No problem for the last seven years.

[hawkdad]

Ok then... quick question related to the Tender Jr. I've had to relocate my r since November to a buddies garage where it will stay until May. Here in the midwest we get temps down in the sub zero's and such... I plugged in the BT(Jr.) and have left it on since then.... Am I begging for a problem?

[CycleRob]

The Deltran Battery Tenders all were designed to be left "on" indefinitely. Their only caution is to check the water level (monthly?) if you have a conventional flooded cell battery.

Here in the South, I don't need a Battery Tender type charger. I ride it at least once, for a decent boil-the-oil ride, in any 10 day period. Right now, while my younger brother in New Hampshire has 19F (-7.2C), I have a cloudy 63.6F (17.5C). BTW, his riding times are much less frequent. To explain why, here is his E-Mail:

"Rob,
We were out of AC power for 6 days. Massive ice storm took down trees – a real mess. It went out last Thursday at 10 PM and it came on Wednesday at 5PM.
My generator was run constantly – handled the entire house. The only thing we didn’t use was the clothes dryer. I changed the oil/filter after 3rd day. It is worth it’s weight in gold. It burns 5 gal every 12 hrs – OHV 13HP 6500W - 8125W surge.
Marty"

See for yourself what I'm talking about (scroll down at these linked weather sites for the 7 day details):
http://www.ibegin.com/weather/us/georgia/gainesville/
http://www.ibegin.com/weather/us/new-ha ... w-ipswich/

His showroom condition Black VT-500C Honda Shadow, to keep this thread on topic, was also on generator power to it's trickle charger in the garage. He just won't be able to ride it until next Spring.
.