BMC STROMER ST-1 ELITE BATTERY PROBLEMS

[jfitzoz]

I purchased a 2013 BMC STORMER ST-1 ELITE less than a month ago. At first, the battery would charge 100% and if not used, the battery lost some of it's charge, but not a lot.

A month later, the Stromer charges less than 100% now to no more than 92% despite repeated charges lasting over 12 hours. If left unused for less than a week the Stromer battery will drop to 42% charge, 42%!

A BMC west coast representative says in a email to me a 10% drop in the battery charge is normal. I say he is full of shit.

The Stromer is the best electric bike I have owned and I have owned A2B Velociti 24, generic 500 watt motor beach cruisers like the Pedego, and non-BMC made Stromer.

I am asking for your opinions about the battery issues. Should I return the bike, have the battery replaced or look for another ebike altogether???

Please respond.

 

[mattrb]

If you are not happy with the bike, you should return it. You will regret your decision later if you don't.

$3,499 can get you anything.

 

[dnmun]

this is the battery that is in the aluminum case? you have no pictures. can you measure the charging voltage and did it change on the charger over this time?

 

[jfitzoz]

Yes, the battery is made by Samsung and is 11.5 amp-hour.

I have not tested battery other than using the display computer that came with the ebike. If anyone could give me some technical instruction I could post the test results. I have a electrical tester.

I agree, I should take it back, but Mike's Bikes is willing to try and fix the problem. I will give them a chance next week since they have other Stromers in stock for parts.

Any help and advice is appreciated.

THANK YOU!

 

[mwkeefer]

Not normal operation unless your talking about a Segway

Seriously though, you shouldn't see a 10% capacity drop unless you've got a bad cell or group developing.

The drainage over a week is why I mentioned segway, it sounds like your having an issue with the balancer / BMS which is likely in the battery pack, pack is replaceable so I would take a replacement and keep trying then... if the new battery gives you a better performance over time then you have your culprit.

At the price they charge for a Stromer though - I'd settle for nothing less than perfection.

-Mike

 

[srmit]

I have an St1 Elite as well, without any battery problems. I read on Stromer forum that you need to disconnect the charger soon after the LED turns green, otherwise the battery starts discharging via charger.

Good luck.

 

[miro13car]

First you must understand that like on other hi quality ebike SOCharge meter is real accurate meter
WHEN is calibrated
You approach everything from wrong side
I highly doubt there is anything wrong with Samsung battery for sure
You battery meter needs calibration by registering the lowest State
Of charge - battery completely discharged until cut off AND by registering full SOC.
I am almost sure your SOC batt meter does not show correct
Make sure it is well calibrated
Again it must register the lowest SOCharge

 

[dnmun]

I have an St1 Elite as well, without any battery problems. I read on Stromer forum that you need to disconnect the charger soon after the LED turns green, otherwise the battery starts discharging via charger.

Good luck.

this can happen. some chargers are made so they will shut off charging when the charging current drops to a low low level and the pack is at full charge. but there is usually a drain down resistor on the capacitors on the output so the battery can drain back down through the charging leads to that resistor.

 

[jfitzoz]

Today, I delivered the Stromer St-1 Elite to Mike's Bikes, Sacramento, where purchased The tech is in touch with BMC/Stromer and will be testing the electronics for the next couple of days. I will pass along all of your recommendations especially the calibration of the LCD computer. This new unit does not have lights to measure the battery strength.

Thanks and I will update this forum again ASAP.

JPF

 

[jfitzoz]

After having the Stromer St-1 Elite tested at Mike's Bikes with BMC/STROMER overseeing the testing I can report that nothing was found to indicate a failure of the battery or the ebike electronics.

The only caveat by the dealer was the battery inside the frame may be too hot in my garage from summer's heat causing the battery to discharge.

Any thoughts or recomendation will be appreciated?

I will continue to monitor the battery issue and report back to this forum in a few more warm months.

 

[jfitzoz]

So far so good.

No battery issues. I learned to charge the battery the night before a ride, rather than a few days ahead of time.

I hate to say it, but the Stromer ST-1 ELITE is the best ebike I have ever owned.

My other Stromer continues to do well without any problems.

My A2B VELOCITI 24 is very good ebike and an excellent used ebike buy!

Thanks!

 

[joepah]

I have an St1 Elite as well, without any battery problems. I read on Stromer forum that you need to disconnect the charger soon after the LED turns green, otherwise the battery starts discharging via charger.

Good luck.

Hey! do you ahve a link for the stromer forum

 

[Paul_G]

I have an St1 Elite as well, without any battery problems. I read on Stromer forum that you need to disconnect the charger soon after the LED turns green, otherwise the battery starts discharging via charger.

Good luck.

Hey! do you ahve a link for the stromer forum

ST-2 will be released shortly....no info or pic's yet

http://gas2.org/2013/09/23/best-electric-bicycles-2014-interbike-2013/