[kennybobby]

If it is a pre-2013 version, then pdove or myself could probably fix it for you, we are over in huntsville/redstone area. If you look in the TCCH Elcon troubleshooting and repair thread there are schematics of the 1.5kW chargers.

 

[pdove]

Bluto74 brought over the charger. It is a TCCH-48-25 1.5kw flooded charger algorithms 105. Its on curve 6 262.8 ah to 316.4 ah. The label says I3 = 8.37A. It was charging 8 US 250 batteries. He switched for 6 Trojan T-875 batteries.

When you plug it in it behaves normally 6 red flashes then solid green. When a battery is connected it flashes red 6 times then goes solid red. The led on the control board starts rapid flashing.

I accidentally connected the battery while the charger was plugged in and it sparked. I am wondering if the output relay is shorted.

 

[pdove]

Here is a picture of the label.

 

[pdove]

I had a few minutes to look at this charger. The behavior has changed but still not working. I believe the output relay or relays are bad. It quit giving me the rapid flash now that I am using a 33 volt battery but when I connect the battery the output relay closes immediately. It doesn't matter if The charger is plugged in or not. I have never seen a relay fail that way.

 

[Coulomb]

... when I connect the battery the output relay closes immediately. It doesn't matter if The charger is plugged in or not.

I assume by "plugged in" you mean it is plugged in to the mains. So is this using energy stored in the capacitors or are you saying that the battery is somehow powering the output relay?

Certainly an odd one.

Edit: either way, it doesn't sound like the relays are faulty, just the CPU is confused or the drive to the coils is bad.

 

[pdove]

Yes the battery is powering the coil on the relay somehow.

 

[kennybobby]

Do you find any continuity between pin 3 of the 7-pin connector and the Battery (+) wire of the output cable?

 

[pdove]

Do you find any continuity between pin 3 of the 7-pin connector and the Battery (+) wire of the output cable?

Everything seems nominal, 13 volts on pin three. Processor miming along normally with daughter board led blinking once a second.

What tipped me off to look for this was I forgot to power the charger and I was reading 20 volts on the red jumpers.

Zero volts on pin three with the charger unplugged

 

[kennybobby]

Maybe that board had a flashover of the relay traces like Mike found on a recent charger, and metal trace residue has bridged over to now energize the coil...?

Unfortunately the boards will have to be removed to replace relays.

Check for continuity between control board pin 22 and the B+ wire, and measure resistance between cb pin 23 and the B+ wire--i think one of these measurement could indicate if a relay coil is shorted to B+.

 

[pdove]

I took a video of this because I've never seen this failure before.

Update: apparently I had a faulty Multimeter. I switched to a Fluke and the output relay appears to behave normally.

I measured 287 volts from the source of Q3 to the Drain of Q4. However, the FETs are to turning on.

I thought this voltage was supposed to be 160 not 247.

 

[pdove]

So,

Just an update since I haven't posted in awhile. Kennybobby replaced the processor, resistor R7, and the op amp which were not functioning. I also found that the output relay driver (Q3) was bad and replaced that myself.

Then I programmed it with new EEPROM values and an a set of firmware I had on my hard drive for a Trojan flooded 24 volt charger. I had to change the table from 12 cells to 24 cells thanks to Coulomb's help to get the right voltage output. It now puts out 27A.

What a team.

I still need to do some calibrating because the serial data doesn't match my meter. Hopefully, I can use Coulomb's Calibrator program otherwise it's a process of trial and error till I get it close. Very time consuming process.