Ping Signalab packed it in?

C

chvidgov.bc.ca

10 kW
Joined
Apr 24, 2008
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812
Location
Victoria, British Columbia
I think I have yet another PING Signalab V2 not working...

All the balance LEDs are on, and the B- to Positive Pack output indicates 60.1 volts. All the "cells" are charged, and reasonably balanced, from back probing the balance leads.

Yet I'm only reading 14.4 on the pack output (P- and/or C-) from the BMS to the positive output...The BMS has shut the pack output down, even though it is charged???

WTF? it just "went bad"...I've had several problems like this, where a BMS just goes bad. I'm beginning to detest these Signalab V2s. This is the second one this year with a problem.

Luckily I have a spare one handy, to put on, but its getting expensive.
 
Are the output FETs being turned on at the gate but just not turning on, or is there no (or insufficient) gate signal?
 
what does 'reasonably balanced' mean? can you list the cell voltages as measured on the BMS at the sense wire plug while the pack is on the charger? what was wrong with the previous signalab BMS?
 
Oops...I found one of the cells is only 3.3. May have a weak cell group. I'll try charging up that group directly and see what happens then.

Is that low enough to shut the pack down? I thought the BMS would shut down the pack if the lowest cell was maybe around 2.5 or something.
 
if you look at the mosfets, there are three legs. the source leg is on the right and is attached to that big gob of solder that all the shunt wires are in.

on the other side of the cutoff middle leg is the gate leg. it is on the left side.

put the black probe of the voltmeter on the shunt or the B- spot, and put the red voltmeter probe on the gate leg, the left leg of the mosfet. see what that says.
 
ok. With the black probe of the multimeter on B-, I get zero volts on both legs of the first mosfet beside the shunt with the red multimeter probe. 1.56V on the middle leg of that mosfet (cut off).

Over the day, the lower cell came up to 3.62 and all the balance LEDs were on, when I came home. So it seems to be balancing.

Does this mean one or more of the output mosfets are hooped?

It still reads 14.8 volts on the main pack Andersons that go to the controller.
 
i don't know what a hooped mosfet is.

that one is not turned on so that is why there is no voltage on the leads.

is there any evidence of broken traces or burned traces or is there a loose piece of solder that got onto one of the legs of the comparator?

can you post up a picture of the BMS to examine, if the cells are all charged, then the comparator shoulda turned on the output mosfets. sounds like the gate is shorted to the source by something.
 
Have you read what's going on in China lately?? Massive inventory that's not being sold. I'm not sure what ping and signalabs sales numbers are like but they might be sending you a product that has been sitting on a shelf for months and perhaps maybe years. This is just my opinion as to why more ping batteries are failing on people.

You shouldn't have to be worrying about the bms or wiring of a battery, that time could be spent riding having fun.
 
I put the new one on...its delivering the juice. The voltage on the left leg of the mosfet gate is 15.06 on this one, unlike the old one. So the old one must have "gone bad" as I originally thought.
Hopefully the pack is ok. That one group might be a little weak - we shall see. I guess the gate driver has died.

I think my next pack will be Headways. I like that BMS better, from BMSBattery.com

Ha Ha...no worries. I've been getting lots of riding - I've put just over 7000 miles on my trike since I built it in 2010, including a 200 mile fully loaded tour a couple of weeks ago through the rugged centre of Vancouver Island. I've got dual packs on the trike, 1200 watt hours in total, one Headway pack and one Ping pack, so lots of redundancy.

I think worrying about batteries is part of the ebike experience for everyone, until the future arrives, of any sort of chemistry.
I do think these Signalabs are a bit flaky though - mine are well protected in a polycarbonate marine box and I can't see why this one failed out of the blue. That's the second one this year (different packs).
 
i have seen where the solder melts on the source trace on the pcb where the shunts are soldered into that mound of solder and the solder flows over and can short out the gate while molten. you can measure the resistance between where the shunts are and the gate to see if it is shorted. but 15V is what to expect normally.
 
How can I tell the difference between "shorted" and "burned out"? Can I steal a mosfet from another burned out Signalab (V1) and repair it? How do I know it is the mosfet closest to the shunt and not one of the other ones?
 
there is nothing wrong with the mosfets. they are turned off for some reason, we never figured out why.

like i said, something has shorted the gate (the left leg of the mosfet) to the source (the right leg).

sometimes this happens when the solder melts from overheating and runs into that little square spot you see where the gate leg is surrounded by the mass of solder for the source leg.

or the gate driver inside the comparator is dead. which could happen if that part of the BMS, the comparator, shorted inside the box to a high voltage point on the battery.

no way to know without looking closely. cannot do it remotely.
 
Well, the pack seems to be fine now, with the replacement BMS on it. I went for a ride with no issues, and all the cell groups read 3.31 after the ride, so the "weak" group was probably just lower than the others, but not damage.
 
dnmun said:
there is nothing wrong with the mosfets. they are turned off for some reason, we never figured out why.

like i said, something has shorted the gate (the left leg of the mosfet) to the source (the right leg).

sometimes this happens when the solder melts from overheating and runs into that little square spot you see where the gate leg is surrounded by the mass of solder for the source leg.

or the gate driver inside the comparator is dead. which could happen if that part of the BMS, the comparator, shorted inside the box to a high voltage point on the battery.

no way to know without looking closely. cannot do it remotely.
Click to expand...

How is it that the solder melts from just normal riding??
 
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