batery tender

Attach tender, put on low amp, charge for 1-2 hours every 3 months or so.

What does a battery tender do? Is it like a charger?

JasonFMHS said:

What does a battery tender do? Is it like a charger?

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It is a charger, but instead of being a "trickle" or "float" charger, it drops into "maintenance" mode after the battery is fully charged so it will not damage the battery if left connected long-term.
The $20 Sears chargers will damage the battery if left connected for a few weeks.

I have battery tenders on all my bikes and they are on whenever the bike is in the garage. Just mount to the battery and find a place to leave the connector where you can reach it - it then becomes available for other good stuff like an electric vest when you're riding. I just changed the battery in my 97 DR650 this summer - 10 years on a battery ain't bad! My 99 ZRX still has it's original battery.

alec said:

Attach tender, put on low amp, charge for 1-2 hours every 3 months or so.

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+1.

silvia-junkie said:

my friend just gave me a batery tender with no instructions. how do they work just atatch the leads and plug in? are you suposed to leave on all winter? will it overheat the batery? thanks.

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Depends: if it is a good one it will have the correct temperature compensation to always hold the battery at the correct voltage. Lead acid batteries need a negative tempco, lower set voltage at higher temps. I think the right set voltage is 14V (+/- 0.5V) at about 25C, and the tempco compensation has to adjust the set voltage about -12mV/C.

If there is no temp compensation, it will overcharge the battery at warmer temps or undercharge it at cold temps.

If it is a good one, then you can leave it on without any issue. A battery tender in general terms means it is an intelligent battery charger. It charges the battery and then drops the charge to where it simply maintains it. Can you identify anything on it, model #, make, etc.?

love2ride said:

http://www.batterytender.com/includes/languages/english/resources/Product_Instructions_BT_Junior.pdf

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From the spec sheet on this one:

TEMPERATURE COMPENSATION (BT PLUS Only): The output
voltage is compensated at -3.5mV/ °C/Cell. This increases the output voltage
in cold climates to keep the battery from being undercharged and, more
importantly, reduces the voltage in high temperature climates to protect the
battery from overcharge.

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One model is temp compensated, I assume the others are not. I would not leave any charger on a lead-acid battery continuously if it doesn't have this feature.