New battery questions

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New battery questions

Postby Kevin » Sat Nov 14, 2009 9:17 pm

Just getting into e-biking and have just started riding an Hightekbikes kit with 36v/20amp LiPo4 battery.
I was expecting to go about 10 miles (at least) per charge with this combination. So when I was attempting to break-in the battery
by running it down to about 50% of it's capacity, as instructed on the web site, I thought I'd be able to ride about 5 miles or so. But, the first two times I rode it, the bike stopped running after about three or four miles, the battery indicator on the throttle showing that the battery was, suddenly, "empty." Is there something wrong, or is this normal when breaking in a battery? I hope I can expect my riding distance per charge to increase.
Also, when recharging the battery with a "high power" 4 amp charger, the battery only takes about 45 minutes to an hour to recharge. Is this normal?
E-bike commuter. Aotema front hub from hightekbikes, 36v20amp LiFePo4. Trek 850 Mountain Track
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Re: New battery questions

Postby StudEbiker » Sat Nov 14, 2009 9:34 pm

Something is not right. Unless you are driving straight up a wall you should get much more than 5 miles out of that battery. I have never ridden my 10ah hightekbikes battery to lvc, and I have (based on charging times only) estimated that an eight mile ride draws about 5ah so I figure it has about a 16 mile range. I always pedal on start and assist most of the time though so you're mileage may vary. Of course you didn't say what you have this on either. I'm assuming your bike doesn't weigh 250lbs. :)
TidalForce S-750-(build #2) w/9C rear w/EV Components Headway 36v 10ah LiFePo4 pack: http://endless-sphere.com/forums/viewtopic.php?f=6&t=15443&hilit=+headway+rack+pack

Bike-E (Build #3, mostly done)- 400W Kollmorgen mid-drive: http://endless-sphere.com/forums/viewtopic.php?f=28&t=25980#p375646
My Bike E Facebook group: http://www.facebook.com/groups/165756106813440/

"Facts do not cease to exist because they are ignored" - Aldous Huxley
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Re: New battery questions

Postby dumbass » Sat Nov 14, 2009 9:45 pm

Kevin wrote:Just getting into e-biking and have just started riding an Hightekbikes kit with 36v/20amp LiPo4 battery.
I was expecting to go about 10 miles (at least) per charge with this combination. So when I was attempting to break-in the battery
by running it down to about 50% of it's capacity, as instructed on the web site, I thought I'd be able to ride about 5 miles or so. But, the first two times I rode it, the bike stopped running after about three or four miles, the battery indicator on the throttle showing that the battery was, suddenly, "empty." Is there something wrong, or is this normal when breaking in a battery? I hope I can expect my riding distance per charge to increase.
Also, when recharging the battery with a "high power" 4 amp charger, the battery only takes about 45 minutes to an hour to recharge. Is this normal?


Have to agree with Stud that batt should be getting a lot more then 3 or 4 miles.Are you sure you charged it fully? I would check the voltage when you pull it from the charger. It should be in the 44v range fully charged.
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Re: New battery questions

Postby dogman » Sun Nov 15, 2009 6:34 am

Capacity would be expected to be less by as much as 50% on cycle one, and not less than 75% for cycle 2, and then something in the 90% range thereafter, so Yes, you have a defective battery or charger in my opinion.

Contact HTB immediately and ask for help troubleshooting, and a refund or exchange if you find a problem. Hopefully you just have a charger that shuts off early, but some stinker cells in the pack is likely.

4 amp charge time for that pack should be in the neighborhood of 6 hours for a fully discharged pack. So either its only got 1/4 of normal capacity or less, or it's only charging to 1/4 of the normal capacity. Step one, is check the output voltage of the charger with a voltmeter. I got a WE kit once with a charger that put out 18v. Needless to say it did not fully charge a 36v sla pack. Then check the voltage of the battery, both on the regular output, and on the wires before the bms. You could just have a stinker bms.

In the future, post a question like this in the battery section. Here it may not get seen by that many battery guru's.
THE LIPO RULES. NEVER ABOVE 4.3V NEVER BELOW 2.7V DON'T PUNCTURE

Ideal charging /discharging range for Lipo, 3.65v minimum 4.1v maximum

See battery technology section, FAQ thread at the top of the page for lipo noob info.
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