I'll start off by saying that I did not do all this work by myself. I have perused some websites, and gathered up this information to put in one place. As with anything, your mileage may vary, but from my research, this is what I've gathered:

For bikes with carbs, battery care is minimal. Clean the terminals, keep the connectors tight, and if you're type-A like me, use some dielectric grease. Never keep them discharged, and they will treat you well. Batteries in these bikes can last for many years with recent reports up to 9 years. Some folks don't even bother keeping them on a battery tender while in storage.

The standard battery in the carburetted America and Speedmaster is a Yuasa YTX12-BS. The EFI America and Speedmaster has a Yuasa YT12B-BS. This battery is about a 0.7 inches narrower as it shares the battery tray with the EFI ECU. One of the confusing things out there, is that many cross reference charts still list the wrong fitment for the EFI bikes, still quoting the YTX12-BS that won't physically fit. Yuasa themselves have the wrong fitments listed on their site, and the only Triumph they currently list for the YT12B-BS battery is for the 2007-2011 Tiger. Don't be fooled!

YTX12-BS Specs (from www.yuasabatteries.com) Use for carb bikes
Battery Family: Maintenance Free
Battery Type: YTX12-BS
Voltage: 12
Capacity: 10
Dimensions: 6" x 3.4375" x 5.125"
Weight: 7.5 lbs.
Metric Dimensions: 150mm x 87mm x 130mm
Metric Weight: 3.4 kg
Polarity:
Acid Volume: 0.6
Amps: 1.2
C.C.A.: 180


YT12B-BS Specs (from www.yuasabatteries.com) Use for EFI bikes
Battery Family: Maintenance Free
Battery Type: YT12B-BS
Voltage: 12
Capacity: 10
Dimensions: 6" x 2.75" x 5.125"
Weight: 7.6 lbs.
Metric Dimensions: 150mm x 69.0mm x 130.0mm
Metric Weight: 130 kg
Polarity:
Acid Volume: 0.50
Amps: 1.0
C.C.A.: 215



One of the inherent features of the EFI bikes is that there is always a phantom load being drawn from the battery. This load has been known to drain the batteries down in under three weeks of storage. There is also a low voltage cutoff programmed into the ECU of approximately 12.6 volts. Also, the ECU does not turn itself off when you stop the engine. There is a delay. On early EFI models the ECU would be on for up to 20 minutes drawing about 0.265 amps. There was a fix for this by Triumph to reduce that time to one minute after the key is turned off. Again, this fix was for the early EFI bikes. The headlight being on while starting doesn't help the situation, either. There is an 8.5 amp load on the system with the ignition on, and fuel pump priming. The load is reduced to 5.64 amps when the fuel pump stops. This initial load on the battery will also reduce its standing voltage.


So, what does this all mean?

1. If you're not using your bike regularly, or using it for short trips, keep it on a battery tender. I typically put it on a tender if it's been sitting for a week or so. My minimum ride is 30 minutes of mixed highway/city.

2. Be aware of the low battery cutoff. The battery will need to be at more than 12.6 volts to successfully start the engine. Some folks have had to go to 13.0 volts before the bike would start. Keep in mind that 12.6 volts is the normal reading for a charged battery. The battery is over 80% charged at 12.5 volts.

3. Idle speed. If the engine idle is less than 1000 RPM, the battery will not charge. This is important for those that do short trips around town.

4. Forget your old ways of not doing anything for the battery in an EFI bike. You have been informed!

5. I don't know if the batteries in these bikes will last as long as the ones in the carb bikes. I suspect that they won't as they are at a constant state of discarge while at rest unless on a battery tender.

Why did Triumph do this to us?

There are basically two reasons why there is a low voltage no-start programmed into the ECU. ECU's cannot reliably retrieve information from the various sensors. If the voltage is low, the sensors feed back inaccurate information to the ECU, and then the ECU makes some bad decisions based on this. Also, low batteries work the stator/alternator very hard. Stators have been known to overheat while trying to charge a depleted battery. As to why the low voltage threshold is so high is an unknown. As we know, automobiles with EFI can drop down to approximately 11.5 volts and still start the engine.

Motorcyclist Magazine had a question/answer on this very topic in their Oct, 2009 issue:

http://www.motorcyclistonline.com/howto/answers/122_0910_ask_the_pro/index.html


Hope this sheds some light for those that are joining the EFI crowd.

By hyates

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