Sharing..........

One of the most important tool I own, is a 33 amps battery maintainer at 13.1V output and it will be 12.80ish volt to battery with 15 amps load from the car.
If we scan our car, must use one of this to maintain proper voltage.

Typical W212 would be up 15 amps during full scan, but you must turn off all standing light.
Over ride the annoying lights with the PARK LEFT or PARK RIGHT selection, where this light will not power up unless key is out of slot.

This time this trusty baby was loaded up at 28 amps for 4+ hours and then burnt smell happened.
I guess its cooling fan activation was slow to repond for quietnes sake.



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#1 is capacitor exploded its bottom end



#2 is I believe a wire wound resistor, burnt to the ground.


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The other side of the board








I like this battery maintainer, its power is decently DC clean output.


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Now a word of caution when buying DC power supply..
You must scope its DC Output Voltage Ripple, otherwise you may get junk. Digital Multi Meter ( DMM) can't detect this, DMM can only read AC voltage ripple.

So in emergency mode I bought this : https://www.skyrc.com/psu_30a?from=nav


When I paid, I realized seller spec was misleading at 150mv ripple compared to manufacturer website at 900mv ripple.




So I thought , I will take a chance.

When I got it, I measured its ripple, holy cow so high !!!!. A pure resistive load of halogen bulb, 50W + 20W at 5.2 amps or 18% of this unit rated power, I am already seeing 5,900mv ripple.


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Based on above test, seller has kindly allowed me to return the Power Supply and get my money back


Compared to my Riden 6024 which is low ripple at supposedly under 240mv

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The exploded one is decent too, ony approx 350mv ripple at 10 amps load.
2 hours before its capacitor exploded, it was serving me well on my friend's car. Good thing no fire occured, just those electronic burnt smell.



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When my new Riden 30 amps arrives, I will mod its cooling system to be extra brutally good.
New 30 amps model now available. I got the Riden 24 amps one already.

Below is landed price with import duty for Indonesia for all three. Shipping is another cheap US$30 only.

I do not know what is the head unit 6030 technical name, but it is the one which controls the voltage level and current level.
It is like a DC to DC buck converter. The 1500 watts power supply is a dumb one at 68 volts max.
They call it : RIDEN RD6030/W 60V 30A DC Voltage Step-down Stabilized Lab Power Supply Module Buck Adjustable Converter

In theory since I am using it at max 14.1V for testing, I can never use the power supply 1,500 watts capability as amperage limit is where I get hit.
The power supply is maximum 65 volts but the head unit allows up to 60V only.


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I took a closer look at my power supply module and it is 800 watts.
Thus the Head Unit Controller RD6024 ( 24 amps ) can only take full advantage at 90% load to power supply or 720 watts if I need voltage of 30V.
30V x 24 amps = 720 watts.

With my current need to simply maintain cars battery voltage, 13.1 volt is the best and not charging the battery more than 2ish amps.
13.1 x 24 amps = 314 watts only and so much un-used reserve power.

Here is a conservative load of 80% max to the 800 watts power supply.


Thus I am ordering 1 more of RD6024 Head Unit to suck maximum power from the said 800 watts power supply.

I tried doing double power supply already, no issue to each/both power supplies.
If double head unit, sharing 1 power supply I would think it will be OK too in terms of precision controls the head unit RD6024 is capable of when havinga twin sister.



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If dual head unit is a success, I can do tripple head unit for the soon to come 1,500 watts power supply and RD6030 60volt 30 amps Head Unit.



To date, I can't fully powered my radiator fan using Battery Maintainer as it needs a unit capable of at least 70 amps stable at 13.1V.
With this tripple head unit set up, I then can do it and a bit more.
I believe when one is doing special programming like BenzNinja works, a good clean and powerful battery maitainer is a must have.
50 amps stable is what Bimmer boys reccomended. I think our W212 could do with stable 40 amps.

If all goes well ,these two power supplies of mine can deliver 86 amps + 48 amps as total capacity at 134 amps at 13.1 volt.

 

I didn't know Nike made battery chargers.

 

noob question. can we check codes with the engine running to avoid the need for an external power source?

 

Love this stuff

 

Full scan is ENGINE OFF , IGNITION ON.
Some modules will go into error mode when engine runnning and then you do a scan on it specifically, example ABS/ESP module called N30/4.

Thus battery maintainer is good to have.

 

Dang, now that you mentioned it, it does look like Nike
https://www.chargerystore.com/

 

Master Surya, you got a burning hot week. Good thing its not your car its blowing caps.

Your new power maintainer will come in handy to replace this one

The previous one did not blow up caps but resistor did with chances on flyback diode + mosfet. You'd need a schematic to know the 50¢ resistor value

caps are mint: no problem!

power resistor got flash vaporized!!

I think the published specs are optimistic!
The max current rating realy is a PEAK duty.

To draw 30Amp non-stop requires a 45 to 50A power-supply hopefully from a single unit.


>> Splitting that load over two units calls for LOAD BALANCING shunt resistors so that high current does not blow both units: one after the other.

>>Root cause ...
Is that resistor cook-off the result of parallel power-supply test ... by any chance??

(Take couple good pics of your power maintainers units so you have a chance of simply buying 50¢ resistor should things get toasty again.)


> Protective R calculation:
-- A 0.5 volts under 25Amp requires a 0.02 Ohms
normalize that near 0.05 or 0.1 for sake of protection.

-- That comes up to a 15Watt duty.
Use a metal strip or cable length for that purpose.

 

If you are just checking for DTCs, there's no need to have an external power source or have the engine running.

 

Closer inspection :

The capacitor plastic jacket melted due to that un-known resistor melting and spreading heat .....but the capacitor aluminum barrel bottom side seem OK. Thus its top part not bulging.





This small chip bye bye already. Melted.


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CR6238 Features

• Up to 5% Precision for Constant Voltage Regulation and Constant Current Regulation at Universal AC input Primary-side Sensing and Regulation Without TL431 and Opto-couple

https://datasheet4u.com/datasheet/Ch.../CR6238-912147


This power supply failed during solo use, indeed 28 amps for its 33 amps rating is too much if 4+ hours non stop load.
I notice this unit fan cooling is rather slow respond.
It was serving a 2nd Land Cruiser 300.

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This is when I do double power supply, on a first Land Cruiser 300.



The Riden RD6024 precise voltage control can be used as load sharing master controller. See above Riden at 21.90 amps and Nike ( ha ha ha ) at 26.6 amps.
I can tune Riden precise voltage selector to allow it to carry more or less amps. Nike voltage control not very accurate. He who has higher voltage will spend more amps, that simple.

Riden can be adjusted to 0.01 volt increment and also its amps can be locked to 0.01 amp increment.

Above, I use Nike voltage adjustment to load Riden.
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Below : I lower Nike output voltage a bit, thus Riden gets more amps. Nike voltmeter is not super accurate. I was trying a 50/50 load sharing



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So the task was this for a PS ( power Supply ):

Toyota Land Cruiser 300 ( LC300) when doing full scan, need minimum 24-25 amps if we set the voltage of PS at 12.8 received at battery post or 13.1V if at Riden or 13.2 if at Nike.
So I use a DMM to read battery post voltage as actual load , including wire's voltage drop. PS built in voltmeter is excluding wire voltage drop you see, thus its higher.
I will set voltage as such car battery gets no more then 2 amps as charging value, thus reducing PS load and also not to harm the car battery.
I have to use my baby current clamp to see what NET amps the battery get.

During the 1st LC300 year 2024 HVAC work , on 1st to 2nd April 2025, I need to trigger command "OPEN" its rear AC solenoid for its TXV, thus I can remove the R134A refrigerant as best as I can
and when doing vacuuming, I also need to maintain that rear AC solenoid to open thus I can dry this entire car HVAC system properly which total has 3 evaparators.
Front AC, Rear AC ( with solenoid ) and Cooler Box evaps, total 3.
I was not using Toyota Techstream software bi-directional command capability of that solenoid valve.....untill later in the day, instead I turn on all its AC blowers to 70% speed.
Thus total power required by a PS is 48 amps approx. So two of my PS-s was needed.


The 2nd LC300 year 2022 also white color belongs to another friend who got jelous that I gave so much HVAC love to 1st LC300 ( white color 2024 ) and wanted the same love....
This time from the start, I use Toyota Techstream to command opening of the solenoid valve for rear AC solenoid. Thus I only need 28 amps and no more 48 amps, as no AC blowers need to run.
I thought 28 amps would be OK for Nike PS to handle....yes it is true for 3 hours 59 minutes but not after that KABOOM !!!! ...LOL




Do not get confused seeing minus, -327.66 Celcius hahahaha. It is what It is during stand by non operational.

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Dual power supply to 1 load is common and PS can handle it with ease.
Since each PS has basically diodes to block reverse flow, it is safe without add on component, as long as there is a load and a battery bank in the circuit.

On yachts we do this all the time. Main engine alternators during cruise will charge its batteries, while the same batteries get charged too by a smart battery charger ( 50 amps ).
So both alternator and battery charger will load share.


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A third jelous LC300 dark metallic blue , year 2024 need my HVAC love this week.. Last week I gave it wheel alignment love, after first LC300 got wheel alignment love from me the week before..
Thus I just ordered locally another RD6024 Head Unit to make my current 800Watt PS module able to do 48 amps or 24 x amps.



Among my close friends, they want me to do what is best for their cars as I see fit.
So if I give love to one, others wants the same love.... LOL.


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I can't wait to try dual Head Unit RD6024 at 48 amps power limit and test my E400 radiator fan again. While it is not enough for radiator fan full load/speed, it should do well at 75% fan speed or duty cycle.

The radiator fan ALONE is 53 amps, but I tested it using car battery without any battery maintainer assistance.





At least 10ish amps ish amps is needed at Ignition ON engine OFF, thus total power required to do this test while maintaining 12.80V battery voltage is a PS of 75 amps solid minimum and stable.
I think at 12.8V stable the total power consumption will be easy 73 amps ( 2 amps to battery as charging ), up from 63 amps below which is at 11.9 volt battery voltage.

 

It's interesting this unit blew up by itself.... because the IC controller switches zero power. It has no heat.
May be resistor is guilty.... I don't think it's a wire wound grade. Good old 1-Watt carbon film.

From the data sheet you linked, we can get the typical application schematic.

flyback circuitry

this is an opportunity to warm up your solder iron for a $10 repair:
regulator: PWM IC-chip
Flyback: diode + R + cap
Power: MOSFET

++++ MOSFET built-in
The schematic makes it looks like the DIP-8 control chip has the power MosFet build right in. No heatsink necessary.... nooo!

This is chip internal affairs...

control only or power handling

...chip got too hot and had to blow up!!!

This chip has a power mosfet built in but no heatsink: there you have it!!

Make sure new unit does not share same goodness.

 

I have exact similar Nike PS I gave to my cousin.
I will borrow it from him to see what resistor is that the one that burnt.

The chip is easy to get locally, and I hope it is not fake one they sell . fake chps with bad performance is common.

case study

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I will renew the capacitors too while at it. Let this be a fun project, he he he.

 

Got the photo of the said resistor from my cousin.




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Not bad, this brand uses 1% resistor.


I bought 1 watt and 3 watt version.
The one on the PS could be a 2 watt version, but minimum is a 1 watt version.

Vishay brand. for both above . https://www.vishay.com/en/resistors-fixed/



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Found seller for the chip. I hope not fake chip.



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I will replace the 2 fatest capacitor








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I want to upgrade at least 1 of these 3, if not all 3. No 1 is next to the burnt pmw chip


Cap 1 is 100uf 35V.
Cap 2 and 3 is also 100uf but 25V. If I can solder new ones, it will be 100uf 63V. I upgraded the voltage. Temperature the same 105C, Cant find higher one.

I hope I can solder these small capacitor .The solder side is so packed with small other components...Dugghh !!!!





I do not know if this resistor went bad or not. I can't read its actual value using my DMM while it is still in circuit. It look like cosmetic damage only........... from the smoke/fume I think.








The burnt 10 ohms resistor fume went all the way to the back, there is a clear plastic in use where I can see the smoke/fume stain better








Oh no....I think this resistor also burnt...DAMN !!!

 

Same. That was my reaction, after my initial reaction of “ugh” it’s like a strong body blow when a favorite tool or component gets crushed.

 

your cousin power supply comes in handy for reference... we're gonna be able to fix yours and upgrade his with a heatsink over DIP-8.


check the flyback diode: forward/reverse

the two 100uF/450VDC caps are input voltage tanks.

The critical caps to significantly iron ripples are the OUTPUT Caps. Like 1500uF /35V low ESR rated.

There's a missing piece... the transformer switching MOSFET. Check it out!

Expectations are if unit is still not running right, it will quickly SEPPUKU...

That's incentive for crossing as many T's as possible before each trial run. Point being: check bad parts first, not after!
🤞

 

I want to cry thinking of the super tight soldering area......



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Double 24 amps Head Unit is alive !!!!! Now I got 48 amps. I would say 46 amps safer.




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Below FAN flow mode is inject fresh air into plastic junctiom box and those 3 big holes will send cool air to power supply metal housing.


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Voltage at alligator clips of Power Supply and Load Bank.



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My Load Bank comes handy. All clicks in place the test assets



The new 24 amsp Head Unit ( Unit B ) give another 10AWG silicone wire to existing alligator clip
So double 10AWG per alligator clip.


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Unit B Riden 6024 Head Unit, its output gets XT90 inter-connector so that I can disconnect it from the alligator clip and not have naked metal connector dangling around.
XT90 is used by RC boys. https://www.servocity.com/female-xt9...nd%2090%20amps!

XT90 Male + female above, sorry over exposed.


I am testing high performance 4mm gold plated banana jack capable of 40 amps.
This is for the Unit B Riden 6024. Well I can swap it around with unit A Riden 6024.



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Need to do balancing between A and B head unit to share load equally.
Highest voltage spread is 0.12 voilts.
New unit B probably has better software and is pumping more current at the same voltage set.
But of course unit A is 2.5 years old already....

 

Both power supply splitting the 50Amp load while regulating voltage is a real balancing act.

These units must be current protected so one doesn't end up at its limit carrying 30A while the other is pumping only 20Amps before getting a short taste of 50Amps...

You know internally: when power transistors are paralleled to split load, .5R load balancing resistors are used for basic protection.

 

The head unit is very advance.
Over voltage protection, over current protection and many more.
This low cost unit is so amazing.

 

Low cost because you designed and built it. If you tried to manufacture and sell it, maybe keeping the cost low would take a lot of effort.

 

I only assembled 1 + 1, not designed it....i wish I am that good

For the DC power cleanliness it produces and the control capability and power rating, this brand is Bang for the Buck and low cost.
However one must know how to use it properly.

 

Start de-soldering components........

Dang 2mm long and 1.2mm wide resistor.



Traced it with its sister unit. 1R5 = 1.5 Ohms



This germ size resistor is OPEN CIRCUIT. So, indeed burnt out.

I can remove it, but I do not know if I can solder a new one



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Damn, burnt hot.




That PWM chip when removed/de-soldered, it broke into pieces like charcoal.




The PMW chip ( chip rail ) went MIA, Courier claimed already sent and I am the one who received it . S.O.B lying bas-tard.
I need to buy again.


Capacitor still OK, measured at 140Uf ( spec 150uf ) both oldie and new ones.

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I do not know if this LCR meter is accurate or the Fluke is the accurate one ?
Will use my Hioki and another Fluke to re-confirm.



For those who likes the look of the Chopstick LCR meter, have a go :


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If I renew the germ resistor and the bigger resistor and the PWM chip and if PS still does not work, I will probably give up.
I am not an electronic guy who can trace a power supply, but I am willing to try my best for knowledge sake.



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"To date, I can't fully powered my radiator fan using Battery Maintainer as it needs a unit capable of at least 70 amps stable at 13.1V."

Is 70 amps the rated steady state current or is it the maximum start-up surge current?

 

Steady state 70 amps. Our radiator fan is a very nice soft start PWM controlled fan, so it has ultra lowein-rush current, like almost nil.
I managed to test it yesterday , just preliminary test : https://mbworld.org/forums/e-class-w...ml#post9149581

 

I am glad you were able to find out the failed tiny resistors.
The tank Caps are used in parallel to act as 300uF together. These don't need to be exact.

Did you test your caps towards the output side? they cleanup the 15KHz ripples.


The burnt 1W resistor is not the culprit, it's a victim. It just saw too much current.
I think there is still bad silicone: diode (A/K) or Mosfet (Source/Drain/Gate) involved with driving transformer primary coil.
If you get us a picture I can point those out.

 

Yes, I agree the CHIP and the burnt 1 watt resistor is a collateral casualty from anothe BAD component.
Must find the other bad components

Here are the overall images


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The grey silicone jacket (4) is a heat transfer silicone.
It touches the base of the alu bottom plate of charger.


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