By: Mike Cecchini
Many non-electrical types do not understand the importance of knowing what their battery chargers are doing (volts and amps) while doing their charging and trickle maintenance jobs. Many of us have more important things to do in life than take time out to learn all the volts/amps/milliamps/watts/charging rates terms that let us understand what's going on. Most of us want something that we can plug-in, hook-up and go on our way to more important things. But the charging rate (amps) and the importance of bringing a battery up to mid-14 volts and held
there for several hours cannot be overstressed so that your bike will start when you want it to start................all the time.
The new generation Absorbed Glass Mat Batteries (AGM Batteries) that do not leak, freeze and do not require any fluid maintenance are a considerable advancement in batteries for all of us motorcyclists. The problem with many AGM batteries is that they have connection terminals that make it difficult to connect to most motorcycle batteries ( http://www.batteryweb.com/powersonicterminals.gif ) so make sure you get one with "NB" (nut and bolt) terminals.
Once I have found a automatic charger (as volts go up---the charge amps go down) that fits my needs (100ma to 10 amps) works for everything I have. http://www.batteryweb.com/productpics/schumacher/520A-PE.jpg , I put it on every battery once a month and leave it there overnight. In the morning the battery is sitting there at 14.5 volts and ready to do anything asked of it.
Here's something that many of you might want to consider. With the new AGM and SP (spiral wound batteries, http://www.batteryweb.com/optima.cfm), the size and weight of a battery can be greatly reduced. Reductions in size and weight (50--80%) can easily be achieved with h-u-g-e cranking power over and above what the normal lead/acid types can produce. For instance, many of our bikes come with 12--16 ampere hour (ah) batteries that weigh in at 10--15 lbs (4.5---7 kg). So........if you downsize to a smaller/lighter yet more powerful AGM, SP or general maintenance free types of batteries you can drop 5--7 lbs and get more cranking amps. Sure, the price goes up about 30%, but well worth it in my eyes.
Also, understand that big singles are the hardest crank over, twins are next and then the multis are the easiest to crank over. The bottom line for most of my bikes (900--1000cc Ducks with 11:1 to 13:1 compression) is that I need serious cranking amps to get these guys to start. So what battery do I use for these beasts ?? A Yuasa/Varta YTX7l-BS ........ http://www.yuasabatteries.com/battery.asp?bID=B8&vID=691
http://www.batteryweb.com/productpics/motorcycle/superioramerican/STX7L-BS.jpg .....weighing in at a mere 5.5 lbs and rated only at 7 ah in comparison to the original 16ah/12.2 lbs of the original battery. The cranking ability of this tiny powerhouse is simply amazing. Racing Ducati owners have been using this guy for years with total success. One well know racer (Bruce Myers of BCM Motorsports) uses the next smaller batter...........a mere 5ah to start his 13.5:1 853cc racing Duck. Frankly I wouldn't have believed it had I not seen it with my own eyes, but the son and I stood there while he cranked and cranked (30--45 seconds continuously) and the big engine finally coughed to life. See http://www.yuasabatteries.com/battery.asp?bID=B6&vID=567
With the diminutive size of the above batteries it will be necessary to reduce the size of the battery box or pack it with some serious dense foam
to house it properly. Those of you wishing to keep the original Bevel battery size (drops right in and hooks up like OEM battery) and step up to
i-n-c-r-e-d-i-b-l-e cranking power get http://www.yuasabatteries.com/battery.asp?bID=B13&vID=5017
Also, with the above sealed maintenance free batteries, there's no more acid over-flow tube to puke acid out over your machine.
Here's enough battery info to answer almost any question:
And a very good site for almost any battery you wish.
Hope this helps.............