Battery replacement

[harper]

I had the battery compartment (which was designed by sadistic midgets) opened to access the ABS diagnostic connector for the bi-annual clutch and brake bleed. I also ordered a new battery because I didn't know the history of the battery that came in the bike when I bought it and someone gave me a gift card to Amazon in an amount that made purchasing a new Taiwanese Yuasa YT14B-BS effectively a $10 expense. Sweet. I tried to find the Japanese version of the battery but was unable to locate one. The one I removed was Taiwanese also so probably not the 2008 factory original but it was qualitatively weak starting a cold engine.

I followed the filling procedure allowing the acid containers to completely empty and then let the battery sit for a couple of hours while I removed the old one. It reached 11.5 V in that time just from the chemical reaction. I installed it and began charging with a battery tender through the tender pigtail I had installed. Not optimal but adequate for a 12 A-H motorcycle battery. I should have charged at 1.2 A for 10 hours but the tender did the job in 22 hours. In the last few hours the tender was delivering of order 300-500 mA.

The voltage at the tender pigtail measured 13.4 V with the ignition off. That dropped to 12.4 V with the ignition on and the panel voltmeter on the bike read 12.2 V. I thought those were a bit low but it started the bike instantly (much quicker than before in my opinion) even after it had been sitting for a few days. I consider that a victory even though I was curious about what I thought to be the low measured voltages. One reason to post this was to see if Ross would scold me for anything I had done.

 

[RossKean]

One reason to post this was to see if Ross would scold me for anything I had done.

Sounds good to me! I agree that it seems a bit low but check it again after you have ridden with it for a little while. I also use a low power (1A) battery maintainer to charge a new battery after adding the acid and find it takes quite a while - longer than theoretical because the process is not 100% efficient. If the voltage is too low for the maintainer to recognize, I will hook the battery up to a low current dumb charger for a couple of hours. The battery takes a surface charge that may take some time to dissipate and the maintainer may cycle frequently between full and "charging" for a while - not actually 100% although it thinks it is. As long as it is working properly, it doesn't hurt to keep a "smart" battery maintainer connected longer. Theoretically forever, but I don't use one after the battery is fully charged. Gets a top-off a couple of times over the 3-4 month winter layoff.

Is your battery maintainer temperature compensated and what is the ambient temperature where the battery and charger are located? Optimal float (maintenance) voltage changes as a function of temperature and slightly higher voltage is needed at lower temperatures (3.9 mV per cell per 1°C x 6 cells). Some maintainers account for this and others do not - typically configured for optimum voltage at 25°C or 77°F. At 0°C (32°F), voltage should be 0.54 V higher than float at 25°C. My NOCO is temperature compensated whereas a Detran Battery Tender Jr. is not. I think the higher end Deltran is temperature compensated.

The OEM (Japanese) Yuasa in my 2011 is feeling its age as well and I think it will be replaced in the spring. 13 years and 160,000 km is enough. Self-discharge rate has increased and reserve capacity is insufficient, especially since I use the bike for camping where I may not have ready access to a boost.

 

[harper]

I have the Deltran Jr. The battery and tender are both at about 50 F right now because they're both in the garage. The charger is always indoors. The bike is mostly outdoors, sometimes indoors.

I have a Japanese, sealed, probably OEM and probably original to my 2006 that was working perfectly when I removed it two years ago. I think it's 18 years old. I removed it only because I didn't know how old it was. It still sits fully charged on my workbench.

 

[RossKean]

The battery and tender are both at about 50 F right now because they're both in the garage.

Probably close enough. I am pretty sure that one isn't temperature compensated but it doesn't make an important difference until you get further from whatever they chose as the set point. Maybe 0.35V or so on the low side assuming 10°C (50F) and a setpoint of 25°C. 15 x 3.9 x 6 /1000 = 0.351

I came across this table that shows the differences as a function of temperature. Note: There is some variance in what various references state as optimum float voltage for an AGM @25°C but most are 13.6-13.8V.

 

[art miller]

Probably close enough. I am pretty sure that one isn't temperature compensated but it doesn't make an important difference until you get further from whatever they chose as the set point. Maybe 0.35V or so on the low side assuming 10°C (50F) and a setpoint of 25°C. 15 x 3.9 x 6 /1000 = 0.351

I came across this table that shows the differences as a function of temperature. Note: There is some variance in what various references state as optimum float voltage for an AGM @25°C but most are 13.6-13.8V.
View attachment 6160

This is an interesting subject. Why is it the Japanese YUASA batteries last so much longer than those not manufactured in Japan? I had two FJR 2007's in the past and never had to change the original battery. My current 2014 was changed last year because it was not holding full charge after sitting over night. I have always kept my bikes on a Deltran Jr tender when not riding and while at home in the garage. In this area of CA the garage temps rarely fall below 50F.