Blue power-on light won't switch off on 48v Dolphin battery. Also beep & battery power-off on 36v.

jonathan75

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Apr 24, 2013
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Hertfordshire
As above. 48v. Samsung batteries. Not ridden in anger for a year. Button for off switch pops in and out as it should but stays blue.

It began when I put the battery on my bike after resoldering some of the bike's wiring. There had been no power going through the system. Still no power now, with either of 36v or 48v batteries. When the 36v Dolphin was put on it just now, and the battery switched on, it would make a high-pitched short beep and its blue light would die immediately. The 48v light didn't die - but now it won't switch off.

Any views really grateful

Thanx
 

Nealh

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Aug 7, 2014
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Check the battery output voltage with a meter if it been standing for a year. possibility a cell group may have drained a bit so you may have to open it to check all cell groups manually.
 
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jonathan75

Esteemed Pedelecer
Apr 24, 2013
785
208
Hertfordshire
Check the battery output voltage with a meter if it been standing for a year. possibility a cell group may have drained a bit so you may have to open it to check all cell groups manually.
Thanks Neal - appreciated. Do you mean the 36v? If so I bet you're right - I'll try a balancing charge (plug it in, leave it on) once I've got the ebike wiring itself fixed.

Could that explain the 48v light not switching off?
 

Nealh

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Check V for both.
 
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jonathan75

Esteemed Pedelecer
Apr 24, 2013
785
208
Hertfordshire
Check V for both.
The 36v which is beeping and immediately dying is on 36v on the button (makes sense as it's 2 out of 3 bars on the battery's charge indicator). 3+ volts when not powered on.

The 48v is showing zero from the power poles. This is wierd as it's on 3 of 3 bars on the side and I gave it a good long-term balancing charge overnight. It is powering the USB output just fine.

I might have damaged it a couple of days ago when I tried briefly to fit it in the mount despite the lock pin being 'out' and it got stuck. After I got it unstuck the light weirdly came with on and stayed on (it's still on).
 

Nealh

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Aug 7, 2014
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For 48v check the fuse hasn't blown as may be why you get nothing on the output side or may be a wire fault.
USB is another circuit about 5v.

36v could be a bad low cell group. If the charger doesn't switch on then most likely the batteries bms is preventing it doing so because it senses low cell V's. The only option is to open and check the 10 cell groups with a meter and manually charge any that are low just enough to allow the charger to switch on.

In both cases you need to look inside to find the issues, there's only so much you can do with out looking inside.

There is no black art to fault finding with batteries mostly it is down to simple exterior testing if that shows anomalies or nothing then you have to look deeper which means going inside.

Fear of the unknown is what prevents most from attempting, there is nothing anyone can do to that will cause any further issues unless of course they are stupid enough to short the cells buy placing something metallic across the cells.
Any one can check a battery with a meter if simple advice given is followed and some clear pics posted for us to see.
 
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