Mark,
Sorry, can you explain what a battery tender is, over a trickle charger, and a brand name?
Jim.
A "charger" could be anything that delivers power. It's exact function can only be derived from its specifications.
There are fast chargers, chargers, trickle chargers and float chargers.
The difference is generally the rate at which energy is provided to the battery, and relates to the battery capacity or C. C is derived from the battery's discharge rating and relates to the current it is expected to deliver. The CB750, for example has a 14 Amp Hour nominal rating. A fast charger could be 10C through 1 C (140 through 14 Amps). A matched-to-battery charger would be 1/10 C or 1.4 amps. A trickle charger would be 1/100 C (0.140A or 140 milliamps). And a float charger would be something like 1/1000 C.
Ideally, a good device would put the bulk of the charge in a battery at the 1/10 C rate, then switch to a 1/100 C rate for thorough chemical saturation of the battery, and then switch to "float" mode to maintain the battery at peak charge. These devices are often called "tenders". As you might expect, a marketing department has actually used that term as a brand name for their product, too.
A battery does not store electricity per se. Electricity is consumed or produced in a chemical reaction. The conversion process generates heat as a by product comensurate with the rate of conversion. Quickly discharging or charging generates heat which can damage the battery. Also, delivering a charge current to a battery that is already at full capacity expends the excess energy as heat also. To prevent damage to the battery, operator inteligence and attendance is required, or a device that can automatically sense what the battery needs and deliver only that energy that will keep the battery in peak condition.
Here is a pointer a more to a more thorough explanation.
http://www.yuasabatteries.com/yuasa05/faqs.aspI have several chargers for multiple bikes. My most recent acquisition was the following automatic 3 level charger that I am very happy to have. However, if i lived in a climate that had wide temperature swings, I'd get one that was temperature compensated in addition to the automatic functions this one provides, as the voltage produced by the chemical reaction in the battery varies with temperature.
http://www.chaparral-racing.com/Chaparral/productr.asp?pf%5Fid=321%2D2101Y&gift=False&HSLB=False&mscssid=423AE45782D74E22AC521578D16C68FACheers,
