Dead Delta q charger

My Delta q has failed and want to see if you think its worth fixing, or now just a parts piece?

2002 e825 with FLA Trojans. New pack in October 2016 and has worked fine til (of course) over one year warranty. Charger started timing out with 4 red flashes in December. I cleaned all terminals (have a watering system to keep wet) and charged individually but problem persisted. Finally determined that at least one battery was bad and replaced it in April. Then I found I had to plug it in, wait for 4 red flashes to start and then unplug/replug a couple of times before it would charge to a steady green.

The car ran fine through this, just a PIA. Finally, after driving it a bunch (and hours before leaving on a two week trip) I plugged in, heard a popping sound and smelled burned electronics. Dead charger. Luckily had my daughter around to individually charge all six batteries while we were gone to save them.

Pulled charger today and opened the box. Here’s what I seen inside.

Not scared of soldering but need some hand holding and parts. Alternatively would be up for a trade in on one that would also handle lithium algorithms as this is strictly a GEM model.

Thanks for your help.

About 50-50 that changing R9 and the relay will fix it. Only about a 10% chance that you can reassemble the charger with the proper insulated heatsink pads, unless you’ve done this before.


There is no factory support or repair. An authorized repair center will replace the guts for cost of a new charger.

As I recall R9 limits inrush and powers charger until the relay pulls in. Power to relay coil comes from the small smps on daughter board that powers the cpu.
The smps may be slow starting or dead. Or it may only be a common failure of R9.

If it was me, break R9 leaving the leads in place. Solder a new one without disassembly.
If it works great. If not 1/2hr work wasted.

I have new chargers in the for sale section. NOS Delta-Q generic 72v.

Thanks for the advice!

How come it’s always the part with the least clearance? I am game to try replacing the resistor. I cleaned out the pieces of char, can I presume the small blob of metal is the other lead?

Can you also spec what resistor I need to buy?

If the blob is indeed the end, I was thinking of using a small (very small) drill bit to poke a hole in the blob and then solder a short lead into it so I can work a bit higher in unit to solder the resistor in place.

You also mentioned it’s difficult to get insulation back in properly, so just taking bottom plate off (which after removing screws didn’t seem to want to come off as easily as the top plate) won’t just reveal the back side of PCB?

Please hold onto one of your DQ units for me until I give this a try.

Is there any core value in a dead charger?

Thank you


These are puzzles. Once the screws are out, heat sinks fall off or break things. It’s all or nothing. I’ve tried all the short cuts.
Core is worth more to you. You can replace the generic end plate and short leads with your Gem ones.
I’ll get the part value for you.

Ok, thanks for looking it up. Are you in Minnesota? How’s the weather today?

100 ohm. about 1 or 2 watt.
I’d get a 5 watt if you order one.

I picked up 2 x 100 ohm, 5w at Fry’s (one small benefit of living in LA is pretty much anything at any time). Straightened the long leg remaining and slipped a bit of shrink tubing over it. The other pole however is the stinker.

It’s definitely a lump of metal and not keen to wanting to melt. After heating a bit I was afraid to damage the board so backed off.

Based on space, and that only a small lead connects the lump to the board, drilling a hole doesn’t appear practical.

Do you think I can heat it enough to free the lead from the board and not damage anything on the backside? I think I can grab with a pair of forceps as I heat it with a small tipped iron and pull off.

Alternatively I am game to pop the back, and try from that side, although cognizant of your admonition about the heat sinks pads. Where are they and what should I be aware of on disassembly? I do see how the end plates can cause problems if not careful since the wires are numerous and some pretty fine. It does seem all have some form of connector and not just soldered onto board as is often found. I am guessing that is due to them making various models with different connections?

Thank you again for all your help.


Can you get a clip lead on it to test charger?

The pads vary from charger to charger. Between the large aluminum and power components.
Near impossible to disassemble partially without breaking parts.

FSIP repairs these now.

Good tip, that’s why you’re an EE and I’m a fool with some tools. Tried it, all that happened was the new resistor got vey hot, no lights came on so I am presuming it’s dead.

I am running Trojan SCS225 FLA, let me know how much for one of your chargers, happy to consider something other than a Delta Q. Would like to be able to upgrade to a lithium system in the future. Also how best way to pay you.


Thanks, looked on their site and with shipping both ways considered not much cheaper than a new unit.

I have a used one for $100 less. $250.
It has generic leads, but your gem leads will hook right up.
Programmed for lithium now, but I can set to any battery type.

The resistor acts as a fuse among other things.
It can only carry the load for a few seconds until the relay bypasses it. In the center of daughter board is a transformer. Below that is an ic that runs the whole start up sequence and leds. You think the resistor is hard to change?

Thanks, I PM you info

These are the profiles I put in it. Set to #3
You can do AGM now if you want.

I found 1 more used charger if someone wants to get one for agm or lithium.

The SCS225 Trojans are equivalent to the 30XHS Trojans. I will defer to you on the right algorithm.

I should send you $251?

How much is shipping?


About $30 will cover shipping.
Make it $275 is close enough.