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Old 05-29-2013, 10:36 PM   #323
Beastly Adventurer
Joined: Sep 2011
Location: Tulsa, Oklahoma
Oddometer: 6,437
Originally Posted by RexBuck View Post
I recently returned from a 6 1/2 month trip to South America. During the trip I started to notice that the bike was having difficulty maintaining voltage at an acceptable range when it got cold and the heated gear was on. During the first part of the trip in fairly cold weather (leaving Canada in October) I had no problems.

When I got into South America and started using heated gear again, I began to notice voltage sometimes falling down to the 13.7 to 13.8v range. It would recover to adequate levels after 5 to 10 minutes of riding. As time wore on, it took less and less to put the voltage into the warning zone and longer to get it back to normal. Usually kept RPMs in the 4K range.

What I have:
  • AntiGravity 16 cell battery
  • Carried a spare stator (along with a ton of other crap on the theory that if you had a part with you, you wouldn’t need it – proved correct)
  • Voltmeter on the bike is a “Voltage Sentry” Meter from Clearwater. It is one of those single bulbs that blinks and changes color depending on voltage. It apparently was designed specifically for a Shorai battery which may account for some unusual color combinations (It’ll be replaced with a simple digital meter soon)

The extra gear on the bike that draws power:
  • Gerbings jacket - 77 watts (with controller)
  • Stock heated grips - 46 watts at high
  • Denali spot lights - 20 watts
  • Garmin GPS – less than 5 watts

So, when I was starting to notice lower voltage, this is what I figured the bike was using:
  • Baseline 147 watts
  • Grips – high 46 watts (Sometimes on low – no difference)
  • Spot lights 20 watts
  • Jacket 77 watts (although this is the maximum draw – while the controller would have been drawing more as it got cold, it was never on the absolute hottest level)

  • High beam was not on
  • It was cool enough and I was going fast enough that the fan was not coming on

Add that up and it looks like about 290 watts were being used which is well below the supposed output of the bike’s stator of around 370 watts

So, thoughts about what could be going on would be appreciated. Is there a component starting to fail? Am I over-thinking this and there is no problem?

I suspect I’ll be taking it to the dealer shortly as hopefully the fix will be a warranty item. Will the AntiGravity battery be a warranty problem? I could stick the OEM battery in if it would be.
Joel has not been very active lately .. so I'll try to help.
note test mule in my LiFePO4 testing thread is an R80G/S .. Joel is the F8 guy!

16 cell = 9.2 amp hour actual, 20 cell = 11.5AH actual
new style A123 are 2.5AH per cell, old style 2.3AH.

with heated gear actual amp hour comes into play in terms of reserves remaining to start next morning. especially in cold conditions.

LiFePO4 reaches full charge at 14.6V ... operating range is 13.3v to 12.85v (20%)

think water flowing in a pipe ... voltage = pressure amp/current = flow

LiFePO4 battery will charge at 13.8v, but rate of charge will be slow. at 14.2v current will be pushed into battery faster, resulting in a fully charged battery quicker.

to check what state your battery is being charged to:

after your normal ride, put bike away .. next morning before starting bike, measure resting voltage. (assuming no excess parasitic drain) note it's important to use a known to be correct meter. cheap $15 meters are fine, if it's been checked against a known meter like a Fluke.

chart below will show state of charge for your LiFePO4 battery.
if your battery shows say 13.6V after resting overnight. it's fully charged, it's probably OK.

_cy_ screwed with this post 05-29-2013 at 10:53 PM
_cy_ is online now   Reply With Quote