24v charge controller help

[petehall347]

this of coomber dance combo 2350 . which are a local company to me as it happens .
have already been up there and used the facilities to swap the amp board so would rather not bother them with this .
ok red fault lights lights constantly they are brand new batteries . charge light never lights . dual diode next to battery connector reads oddly on the board as reads in reverse on one side and other side because parallel resistor . v4 smd dual zener diode . looks like its been changed before .
will get better pics .

[petehall347]

Re: 24v charge controller help

more pics

[petehall347]

Re: 24v charge controller help

talking to myself again as nobody joining in ..ordered 50 dual 3.6v zeners . in the hope it will fix the issue . they are only 1.2 pence each so can afford to drop a few on the floor .

[redwire]

Re: 24v charge controller help

SOT23-6 switcher does all the work? It doesn't look like much of a power supply.
All parts are tiny except for the big inductor and diode, and almost nothing for output capacitor 47uF.

The SOT23-3 part is the one giving you trouble?, I would trace out the circuit a bit and it looks like it's for current-limiting the battery charger. The three R220 current-sense resistors eventually go to the base.

[stj]

Re: 24v charge controller help

i dont even know what this is - more background would help

[petehall347]

Re: 24v charge controller help

i dont even know what this is - more background would help

the board basically tells state of charge .or rather it should do . red light should go out when charged enough but is staying on . the other lights should also light when charging but dont .
one thing i cant figure out is why the charger is only at 24v open circuit when the batteries need 27.6v to charge properly .
the red led is the one nearest the dc input socket .

[stj]

Re: 24v charge controller help

well it's several circuits then.
a voltage sensor, and a charger.
the sensor probably drops the charge from 27+ to 24 when the battery stops drawing current to keep it toped off.
so first move is to give it a constant load like a lamp across the battery to force the charge to continue.
then see what it does.

[petehall347]

Re: 24v charge controller help

no the charger only supplies 24v . unless it rises with load .
will see if i have a 24v lamp

[stj]

Re: 24v charge controller help

well if it supplies 24v then it wont charge a 24v battery.

[redwire]

Re: 24v charge controller help

From the big inductor and output diode, it's a boost converter configuration.

It looks like a microcontroller drives the LEDs and does charge control. Or it's a UCC battery charge controller.

I would get the part number of the SOT23-6 part and take some readings on its pins to see if it's held off or is dead.

[petehall347]

Re: 24v charge controller help

sot23 6 . is a 562n .whatever that is ...4 pins connect together on the board .

8 pin device next it is s14b ..or 514b

other chip is MRC019 it 013 ,
they are hard to read even with magnification .

[redwire]

Re: 24v charge controller help

SOT23-6 mosfet FDC5612 N-ch 60V 4.3A
S14B is LM3478MM switching regulator
No hits on MRC, it might be a MCU. It's the top marking line that matters, EZD5?

Why a 4-pin battery connector, and that one soldered part looks like a train wreck.

I would trace out some of the circuit.

[petehall347]

Re: 24v charge controller help

4 pin connector as 2 12v batteries to make 24v .

EZDD by the looks of it

will get get those 3 voltages tomorrow for 6 pin fet

[petehall347]

Re: 24v charge controller help

just checked the v4 marking before replacing and noticed its a wv4 and not a zener ..
BAT54S .. it checks ok in circuit apart from the 100 ohm resistor across pins 1 and 3 making it not possible to check it .
will get those voltages soon .

[petehall347]

Re: 24v charge controller help

voltages at 6 pin fet
drain 23.9v
gate 0v
source 0v .
this is using - at dc socket as ground reference . 24v supply and batteries connected

[petehall347]

Re: 24v charge controller help

way i am seeing this is lm3478 is not working . all other pins appear to be fine and connecting to where they should .

[petehall347]

Re: 24v charge controller help

figured out the ezdd .. lm3478 .. op amp . its vcc is fed of the bav70 dual diode from the batteries . so looking like it has multiple problems .. i tried jumping the bav70 with a diode but no change with lights obviously as its not charging .

[redwire]

Re: 24v charge controller help

It's a quad op-amp for the charge controller? What are the three LEDs and the 6-pin connector for. It looks like some signals come from the other board.

The charger seems to monitor the battery pack center (12V node), and that is the portion somebody soldered up and mangled the transistor there. That might set the fault LED, if it can't see the pack midpoint voltage.

[petehall347]

Re: 24v charge controller help

6 pin connector goes to amp board .
i ordered a new pwm controller .
yes it goes to centre voltage of batteries .
looks like op amp is for led lights ..
red is for battery fault ..
other 2 are state of charge and charging lights

one side of dual diode thats badly soldered goes to pin 11 of op amp . + input 4 .
other side to ground

[petehall347]

Re: 24v charge controller help

have had word this board is obsolete so i cant chance ruining it .
dual diode replaced that powers op amp is now replaced and working .
the other dual diode the zener one that goes to battery centre will be here soon . old one sort of tests working out of circuit . it makes me wonder if correct replacement was used last time .
pwm controller is being slow to arrive . hoping i dont need it as no good way way of getting old one removed as yet . need the hot air .