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Old 08-24-2013, 10:54 AM   #6
Beastly Adventurer
Joined: Sep 2011
Location: Tulsa, Oklahoma
Oddometer: 6,443
Originally Posted by Rockwell View Post
I have a Battery Tender Junior and a voltmeter with me.

A lady in town offered to take the battery home with her to charge overnight (we are tenting and had no electrical outlet available). She brought the battery back this morning and said it was fully-charged. I installed it and tried to start, but there wasn't enough cranking power. I placed it on the charger after because, since I hadn't personally charged it the night before, I wanted to make sure I had a fully-charged battery.

After a few hours, the battery tender indicated fully-charged. I attempted to start, but there wasn't enough cranking power.

I have a Lithium-Iron battery - Shorai.

I am suspecting a bad battery since it didn't crank over with it fully-charged, but I will charge it again, and measure the fully-charged voltage. If it doesn't start, I'll need to get a boost and, when I do, I'll measure the output of the rectifier regulator. I'll have to look at the wiring diagram, but I guess this will be applied directly to the battery terminals when the bike is running?

In the meantime, if it is a bad battery, is it safe for the rest of the motorcycle to get a boost while we try to get to Reykjavik to get a new battery?
Originally Posted by Rockwell View Post
Connections are tight. I just fully charged the battery. Voltage read 14.25V. Tried to start and it just didn't have the cranking power. The battery voltage now reads 13.2V. I wasn't able to monitor the battery voltage when attempting to start since I couldn't hold the leads and start the bike at the same time, but I am guessing that the voltage is dropping really low when starting.

Bike is able to start with a boost and will run fine.

Looks like we're heading back down south to Reykjavik to look for a new battery. :( Could be worse.

This battery was fine until it got off the plane from New York. Could the cold during shipment have had any effect on the battery?
more basic info please ... what model KTM? what model Shorai? need night time/day temperatures?

14.25v indicates a fully charged LiFePO4 battery. voltage drop to 13.3v range after one start is perfectly normal. if your Shorai battery will not start your bike at moderate temperatures, it fails the load test. if your bike starts every time with booster cables, then your starter is fine. are your battery terminals corroded? what condition are your battery cables on bike?

LiFePO4 performance like any PB battery drops severely when temp drops. difference is actual amp hour reserve of LiFePO4 will be lower than PB. stated AH on Shorai is not actual, but expressed in PB/EQ. one of the most common reasons for LiFePO4 failures is under sizing.

my recommendation for KTM doing Adventure duties far from home in cold conditions is to size LiFePO4 battery by actual amp hour. if say your original AGM battery was 11AH ... the correct LiFePO4 should also be 11AH actual or larger.

there's been all sorts of negative feedback about Battery Tender Jr killing LiFePO4 batteries. almost any PB charger can be used to charge LiFePO4 if voltage is monitored. don't use any PB charger that charges above 14.6v. now to confuse issues... during bulk phase of charge voltage is not critical. finishing voltage is critical, if left on charger for extended periods, like months at a time. short exposure to higher voltages usually will not hurt.

EarthX currently offers the most advanced LiFePO4 motorcycle batteries. with internal cell balancing, overcharge and under discharge protections. most any PB charger can be used. most important is EarthX cranking performance under cold conditions.

for more information on this issue .. follow link in sig below.

_cy_ screwed with this post 08-24-2013 at 11:15 AM
_cy_ is online now   Reply With Quote