9C 2810 Failed..... :(

[dnmun]

what is the output voltage on your charger and what is the BVds?

[Tommy L]

what is the output voltage on your charger and what is the BVds?

Battery never gets charged while plugged into the controller. I charge the 10 13.2v pack of 4S4P in groups of 3 at 43.1v max. The charger starts with low
voltage and 4.5amps and then drops the amperage down after the bulk phase.

Not sure what is BVds

Tommy L sends...

[dnmun]

the drain source breakdown voltage of the mosfets. i thought you had 40S of the A123.

[Tommy L]

the drain source breakdown voltage of the mosfets. i thought you had 40S of the A123.

Yes. 40s in a 10 x 13.2v nom 4S4P packs in series. Or should I not call it 40S ?

Thank you kindly for your efforts dnmun!

Tommy L Sends....

[hjns]

Definitely open the controller and check all FETs. I cannot say I understand controllers, but I can solder. If you can do that, then it is possible to replace any smoked FETs, although still a PITA.

Each MOSFET has three legs. There should be resistance between any of the legs of one FET. Once you opened the controller, you then turn the board up side down with the bottom of the board facing up. You then check for resistance. Zero resistance between any of the legs is a shorted MOSFET. Check all FETs, and replace all smoked FETs.

viewtopic.php?p=494317#p494317

[Tommy L]

I just changed the Subject ....

Bank "C" The "BLUE" bank has 3 FETs that show Continuity

[dnmun]

each phase has mosfets between the B+ of the battery and the phase wire so current can flow into the phase wire. these are called the hiside mosfets.

between the phase wire and ground there are mosfets to drain the current from the phase wire to the ground, or B- of the battery. these are called the loside mosfets.

the mosfet has three legs, gate, drain, source legs when looking from the front, left to right.

the mosfet has an internal diode. if you connect positive to the source, and negative to the drain then current will flow through the mosfet, as it does through a diode. you can measure that forward voltage bias with the diode function on your meter.

the hiside mosfet is installed so the battery plus is applied to the drain and the source is connected to the phase wire. so this prevents the current from leaking through the body diode of the mosfet because it is now 'reverse biased'. it will appear open circuit.

the loside mosfet has the drain attached to the phase wire and the source leg to the battery B-. same thing as with hiside, phase wire is positive to the battery B- so it is reverse biased too and should be open circuit to your meter.

you should be able to see that when you examine how the traces run on the underside of the pcb.

test each of the mosfet body diodes with your meter. they should all be identical except the ones that shorted.

when the mosfets are connected in parallel, if just one is shorted the adjacent ones in parallel will appear shorted also whether they are or not. replace all three in each bank that is shorted.

[Tommy L]

each phase has mosfets between the B+ of the battery and the phase wire so current can flow into the phase wire. these are called the hiside mosfets.

between the phase wire and ground there are mosfets to drain the current from the phase wire to the ground, or B- of the battery. these are called the loside mosfets.

the mosfet has three legs, gate, drain, source legs when looking from the front, left to right.

the mosfet has an internal diode. if you connect positive to the source, and negative to the drain then current will flow through the mosfet, as it does through a diode. you can measure that forward voltage bias with the diode function on your meter.

the hiside mosfet is installed so the battery plus is applied to the drain and the source is connected to the phase wire. so this prevents the current from leaking through the body diode of the mosfet because it is now 'reverse biased'. it will appear open circuit.

the loside mosfet has the drain attached to the phase wire and the source leg to the battery B-. same thing as with hiside, phase wire is positive to the battery B- so it is reverse biased too and should be open circuit to your meter.

you should be able to see that when you examine how the traces run on the underside of the pcb.

test each of the mosfet body diodes with your meter. they should all be identical except the ones that shorted.

when the mosfets are connected in parallel, if just one is shorted the adjacent ones in parallel will appear shorted also whether they are or not. replace all three in each bank that is shorted.

dnmun..... don't you ever sleep? lol I'm glad you are here..... really!
I'm an amateur radio op and was comms/electronics in the Canadian Military for 22 years. Mostly the Comms side and decided to self teach myself
electronics as much as possible, but I'm only "dangerous" to say the least... lol My gift is understanding other experts and being able to apply
what I learn

I noticed that the 3 fets in bank "C" were paralleled therefore all showing shorts
But from your explanation, I now can see the Hi/lo sides Thank you!
The 3 FET's in question on Bank "C: are on the Bat + HiSide.

I'm leery to apply voltage to the FET's in question as I'm not sure how this is done. Do I fire up the power to the controller?
Also leery to do this as the traces/Solder dams are very close together.

Have I determined the bad FET's already and just need to replace the 3 in Bank "C" hiside?

What a mess this will be. I wish they had just used heavy copper traces instead of solder.

Tommy L sends....

[dnmun]

don't have power in the controller while measuring the mosfet bias.

you can see the diode function on the meter. put the red lead on the source, the black on the drain, it should read out the forward bias at low current.

reverse the leads and it should be open circuit.

but dead is dead when it is shorted.

[Tommy L]

don't have power in the controller while measuring the mosfet bias.

you can see the diode function on the meter. put the red lead on the source, the black on the drain, it should read out the forward bias at low current.

reverse the leads and it should be open circuit.

but dead is dead when it is shorted.

I preformed the Diode test using the meter on that mode. I see how by design the have the source flipped between the hi/lo sides
I checked all hi/lo and it is still the 3 hiside on Bank "C" phase that show a short.

Tommy L sends....