Is My Victron Multi Dying ?

[goboatingnow]

Originally Posted by s/v Jedi

Okay, this is an aspect not yet discussed... your unit is 120V, 2000W, 12V, 120A. What you're looking at is a 120V 2kW inverter and a 12V 120A charger. Do not assume that the charger is 2000W because that isn't how it works (although 2 kW will be it's maximum output).

Your maximum bulk voltage for the batteries we use is under 15V. When we multiply that with 120A, we get 1,800W. In bulk mode (look carefully at the graph I posted, there are two lines and scales: voltage and current... the Victron and every other smart charger has the same graph by the way)... so, in bulk mode, the current is constant, a horizontal line, at 100% of charger rating, which is 120A at 25C, let's say 105A in your temperature. This is called de-rating because of environment factors, but for calculations with levels of power output in %, we keep using 120A because 100% output becomes de-rated to 105A and that is 100% of the charger power in that environment. The charger has forced air cooling and the fan will switch on (does it???!!!!) to keep the unit cool enough if ventilation is ok. During this phase, with the current at 100%, the voltage starts at where the battery was before charging was started, let's say 12V. This means that the charger puts 12*120=1,440W into the batteries, well below it's power rating. At the end of the bulk phase, the voltage has come up to let's say 14.6V so output is 14.6*120=1,752W which is still well below the unit's 2 kW rating (it mostly uses the same circuitry for charging and inverting). The derating means that you replace the 120A with 105A but percentages stay the same.

So what changes during the bulk phase is both the voltage and the power transfer, while the current is fixed. That "current=fixed" is the identification of a proper bulk phase.

Nick in bulk phase any smart charger is a constant current source,( for the most part and in general) the terminal voltage will rise as the battery charges, but the current does taper off, no charger exists bulk mode with the same current going in to it as when it started

These stylised graphs that are presented are somewhat misleading absorption is not a sharp cutoff point

heres a real life graph

[s/v Jedi]

Originally Posted by goboatingnow

heres a real life graph

Hmm yes but this graph does not show charger output current. When output current goes down during bulk phase, the unit has inadequate cooling. This might be due to design cost savings or due to wrong installation (no ventilation etc.)

ciao!
Nick.

[Dreaming Yachtsman]

This morning I installed a new cooling fan in my Victron and am happy to
report that the charger now charges as expected. I am embarrassed at how long it took me to recognize the real problem, though.

Lessons Learned:
1. Rule out the obvious before trouble shooting issues that were never a
problem before.
2. To test the fan, disconnect J3 or J4 from the main control board. That
trips the overtemperature circuitry which energizes the "temperature" LED
and starts the fan.
3. The over temperature indicator works only in inverter mode. A built in
safety circuit depowers the unit when it overheats in charge mode. (This
was my original problem.)
4. The temperature sensor can be disconnected from the control board by pulling the terminal block off its posts without releasing the set screws holding the wires in.
5. Replacing the fan was relatively simple even though it required
removing both circuit boards from the case to reach it. Anyone with
moderately decent mechanical skills can do it.

Thanks to all of you for your support and advice.

Now back to buffing and waxing.

[s/v Jedi]

Good news, happy I could give you the correct diagnostic. Now let's wait and see how Floyd handles the news

I must say I found it a bit disappointing that so few members actually know how the charge phases are supposed to work, while everybody stumbles over each other tostate which charger is better etc.But that is CF I suppose haha.

ciao!
Nick.

[CarlF]

Geez. That's why I love this board.

Was your fan not coming on at all or was it not working well enough?

My Victron Multi occasionally shuts down when charging. It is rare enough that diagnosis is difficult. I had always assumed some other gremlin since the fan does run and the overheat light wasn't on. I love Victron equipment but I wish their documentation covered details like the overheat light not working in charge mode (or did I miss it in manual?)

Carl

[Dreaming Yachtsman]

Originally Posted by CarlF

Was your fan not coming on at all or was it not working well enough?

The fan was not coming on at all. I suspect it developed some corrosion on its bearings during off-season storage and didn't develop enough torque to break free. (Same thing happened to the pump motor in my food vacuum sealer.)

Originally Posted by CarlF

My Victron Multi occasionally shuts down when charging. It is rare enough that diagnosis is difficult. I had always assumed some other gremlin since the fan does run and the overheat light wasn't on. I love Victron equipment but I wish their documentation covered details like the overheat light not working in charge mode (or did I miss it in manual?)

Carl

During the past 3 weeks I have read every word in both the users manual and the installation manual multiple times. Nowhere is it mentioned that the "temperature" light functions only in inverter mode.

Can you tell whether the fan was running when your unit shut down?

[CarlF]

The fan definitely runs but I'm not 100% sure it was running at the shutdown (since it is a rare event and not reliably duplicated ). I have the added amusement that I have two multi's in a master/slave relationship. I guess it could be either fan. I will unslave them and test individually.

But the information that the it can overheat with no overheat light certainly suggests an explanation.

Thanks again.

Carl

[impi]

Originally Posted by s/v Jedi

Hmm yes but this graph does not show charger output current. When output current goes down during bulk phase, the unit has inadequate cooling. This might be due to design cost savings or due to wrong installation (no ventilation etc.)

ciao!
Nick.

Nick, i am seriously imporessed with your thinking my man ... well done!

Question: What temperatures for battery charging is acceptable?
My temperatures are now running in the mid 30*C range, whereas in South Africa they were max 21*C.

The ambient temperature here in Grnada is much higher as is humidity.

Another observation : When absorption mode kicks in, the bulk mode light stays on as well ... that is new and ever since arriving here?

Float also kicks in a lot later ... up at 90% state of charge?

Any ideas?

Sorry to be using this thread ... hope thats ok!

[goboatingnow]

Originally Posted by s/v Jedi

Hmm yes but this graph does not show charger output current. When output current goes down during bulk phase, the unit has inadequate cooling. This might be due to design cost savings or due to wrong installation (no ventilation etc.)

ciao!
Nick.

Yes sure, I wasn't really focusing on the OPs problem. I was just pointing out that in real life the state transitions aren't so explicit.

Dave

[s/v Jedi]

Originally Posted by impi

Question: What temperatures for battery charging is acceptable?
My temperatures are now running in the mid 30*C range, whereas in South Africa they were max 21*C.

The ambient temperature here in Grnada is much higher as is humidity.

Another observation : When absorption mode kicks in, the bulk mode light stays on as well ... that is new and ever since arriving here?

Float also kicks in a lot later ... up at 90% state of charge?

Charger temperature can go up to 50-60 C without damaging the charger. Check if the fan is operational.

You also need to check the light combinations.... bulk + absorption means something... battery protection? Your batteries might have changed with the climate temp.change instead of he charger, or are getting tired.

ciao!
Nick.

[Dreaming Yachtsman]

Originally Posted by s/v Jedi

You also need to check the light combinations.... bulk + absorption means something... battery protection? Your batteries might have changed with the climate temp.change instead of he charger, or are getting tired.

Yes, the term Victron uses is "Battery Safe" mode. They describe it in Appendix C as:

Battery Safe Mode:

The applied voltage to the battery is raised gradually until the set Absorption voltage is reached.

The Battery Safe Mode is part of the calculated absorption time.
My interpretation is that it is a transition between bulk and absorption modes.

impi, You didn't specify whether the temperatures were battery temps or charger temps. From the numbers, I suspect you were refering to battery temp which will adjust your absorption voltage but otherwise shouldn't greatly affect the charge profile.

By all means use this thread to help solve your problems. One reason I started it and kept it going so long was to allow others with Victron inverter/chargers to gain from my grueling experience.

[impi]

Originally Posted by Dreaming Yachtsman

Yes, the term Victron uses is "Battery Safe" mode. They describe it in Appendix C as:
Battery Safe Mode: The applied voltage to the battery is raised gradually until the set Absorption voltage is reached.
The Battery Safe Mode is part of the calculated absorption time.
My interpretation is that it is a transition between bulk and absorption modes.

impi, You didn't specify whether the temperatures were battery temps or charger temps. From the numbers, I suspect you were refering to battery temp which will adjust your absorption voltage but otherwise shouldn't greatly affect the charge profile.

By all means use this thread to help solve your problems. One reason I started it and kept it going so long was to allow others with Victron inverter/chargers to gain from my grueling experience.

Thank you for that ... This is a great thread!
The temperature is battery temperature ... And this is the first time I have observed both bulk and absorption light on at the same time, with float only kicking in once in the 90% state of charge range.
We have two victron 3000/120 in parallel charging exide deep cycle gels (which gels are now 2 hrs old and have completed 80 cycles.

[Dreaming Yachtsman]

Apologies in advance for resurecting this old thread but I have a new problem. More of an inconvenience really.

The boat just came out of 6 months of dry storage in Puerto Rico so I wanted to perform an equalizer battery charge before restoring DC loads. Following the instruction manual, I switched the rocker switch in rapid sequence from "On" to "Charger only" to "On" to "Charger only". I tried several times at various tempos to ensure operation was according to the manual. The Bulk, Absorption, and Float LED's never flashed as they were supposed to.

Has anyone with a Victron Multi successfully initiated an equalizing charge using the front switch? If so, what is the trick?

Fortunately the sun was out that day so I did the equalizing charge with solar power. Since solar may not always be available, I would like to know whether I have another problem with my Victron.

[skipmac]

Originally Posted by Dreaming Yachtsman

Apologies in advance for resurecting this old thread but I have a new problem. More of an inconvenience really.

The boat just came out of 6 months of dry storage in Puerto Rico so I wanted to perform an equalizer battery charge before restoring DC loads. Following the instruction manual, I switched the rocker switch in rapid sequence from "On" to "Charger only" to "On" to "Charger only". I tried several times at various tempos to ensure operation was according to the manual. The Bulk, Absorption, and Float LED's never flashed as they were supposed to.

Has anyone with a Victron Multi successfully initiated an equalizing charge using the front switch? If so, what is the trick?

Fortunately the sun was out that day so I did the equalizing charge with solar power. Since solar may not always be available, I would like to know whether I have another problem with my Victron.

I tried once with my Multi without success. I also was unable to program the charger bulk and float voltage with the dip switches as shown in the manual. Even swapped emails back and forth for a couple of weeks with the US tech support guy with zero success.

Finally downloaded the VE Config software and purchased the interface and was able to quickly get it working correctly. What I found was some setting in the Victron that could not be controlled or changed by any switch that was over-riding the battery type setting.

Will check it out next time I'm on the boat but willing to bet I can get the equalization mode using the software.

So far I think I like the Victron but there are certainly some bugs in the system.

[btrayfors]

John,

Yes, I've been able to get mine to go into the equalization mode several times, using the remote control. It wasn't easy, however, and required quite a bit of fiddling with the switch before I got the right sequence and rhythm.

Keep trying....don't give up. It will work, but just takes patience.

For such a premium piece of equipment, this is a very stupid design issue; Victron should be ashamed.

BTW, I do all the programming via the software interface, too. The dip switch configuration is another bugaboo with the Victron, and the instructions are darned near indecipherable.

Bill