Victron Multi/Quattro charger output level?

[twistedtree]

I know a number of people here are using Victron Multi or Quattro inverters. When bulk charging, are you getting the rated charger output current out of the unit, and does it continue at full output through bulk charging?


I know they de-rate in ambient temps over 25C, but I am hearing of units that never produce more than about 75% of rated output other than the first few minutes of operation, and when ambient is still at or below 25C. In other words they don't meet specs, not even close. So I'm curious what the "community" is seeing?

 

[CharlieJ]

The temperature of the internal components is the limiting factor. There are temperature sensors on the FETs and on the toroidal transformers that will cut back power to protect the equipment as the temperature limit is approached.

See: https://www.victronenergy.com/support-and-downloads/technical-information and scroll down to: Output rating, operating temperature and efficiency

Something I didn't know is:

In general the toroidal transformer is the limiting factor in our inverters and inverter/chargers, while semiconductors are the limiting factor in our battery chargers. This explains the difference between the curves shown in paragraph 1 and paragraph 2.

This all just means that the operator must keep as much cool air available so that the waste heat can be removed to maximize performance.

 

[ScottC]

Have you had a look at the configuration using the VE Configure software? Lots to see and adjust in there. MK3 Usb dongle required, at least on my old setup. May be entirely blue tooth now…

 

[Simi 60]

I know a number of people here are using Victron Multi or Quattro inverters. When bulk charging, are you getting the rated charger output current out of the unit, and does it continue at full output through bulk charging?


I know they de-rate in ambient temps over 25C, but I am hearing of units that never produce more than about 75% of rated output other than the first few minutes of operation, and when ambient is still at or below 25C. In other words they don't meet specs, not even close. So I'm curious what the "community" is seeing?

Our 5000/120/24v multiplus smashes close enough to 120amps in the early morning before sun up.
Up and down a bit at times as small house loads come on
But as the sun comes up the solar throws the numbers off in the +

We rarely run the Genset for more than 2 hours but when we do, it works as advertised.

 

[rslifkin]

I've seen my 12/2000/80 put out right around 80 amps for at least an hour. Not sure I've put it in a situation to push full output for much over an hour. It's mounted in the fairly cool forward bilge which helps.

 

[ksanders]

I have a pair of Multiplus units and am getting full output, but I found a setting that many people use that limits charge current, but is not widely known to do that.

The manual indicates to flag a input as a "weak input" if you are using a generator.

If you do that the multiplus will only go to about 75% of it's output.

Once I removed that flag the multiplus units have performed to specification.

 

[twistedtree]

The temperature of the internal components is the limiting factor. There are temperature sensors on the FETs and on the toroidal transformers that will cut back power to protect the equipment as the temperature limit is approached.

See: https://www.victronenergy.com/support-and-downloads/technical-information and scroll down to: Output rating, operating temperature and efficiency

Something I didn't know is:


This all just means that the operator must keep as much cool air available so that the waste heat can be removed to maximize performance.

Agreed, and I saw that bit that they posted. However their specs and their paper on derating say that the device should produce 100% output at 25C ambient. That means the internal cooling should be able to stay within range to produce full output under those conditions. These two particular installations are running at 25C or lower ambient, yet the internal components (assuming that's what's throttling it) aren't keeping cool enough to delivery the specified current. So I don't think it meets specs, and misses, by quite a lot. So I'm trying to gather data to see what others are experiencing in practice.

 

[twistedtree]

OK, this feed back suggests there are setting issues. I have both people looking at the Weak AC setting, as well as the charger current limit. It might also be more specific to the large Quattros in this case - 24V/8kw.

 

[ScottC]

For what it's worth...

My Multi is a 48 / 3000 / 35 - 16 (230/240v 50 Hz) Vintage ~2010
I just checked my VE Config settings:
Charge Current limit is set at 35 Amps
Weak AC Input Box is checked/ticked (because more often than not, I’m dealing with dodgy A/C input)
Bilge temp (where the Multi is located) is typically 22-30 degrees C during the summer. Engine is in a separate cocoon, so the higher temps are pretty well confined to that.
When arriving at a marina with an empty 48v battery (i.e. at 44v) and plugging into good shore power (i.e. in my case, capable of providing full 16 Amp input with out tripping the breaker on the dock), I regularly see 25-30 amps coming into the battery during Bulk and this does not diminish over time while in the Bulk phase. It's not 35 Amps and not constant because I always seem to have 5-10 Amps draw from other "stuff" that gets priority over charging (refrigerator, pc chargers, appliances, etc). This observation/comment for my situation is after sunset, so there is no confusion added due to varying solar panel input, as would be the case during daytime charging.

I also have the “Stop after excessive Bulk” box ticked (config came from the factory that way). More often than not, my challenge is to get the 48V battery fully charged overnight while I sleep. If I can’t draw the fully 16 Amps from shore power (which is often the case), My battery may not get fully charged overnight, even if the night is long enough. After some research, I found out that the “Stop after excessive Bulk” setting stops all charging after 10 hours, if the bulk cycle has not completed. This is a safety feature in order to prevent run-away-charging and battery damage, fire, etc. So, as much as I am annoyed by a stop after 10 hours on occasion, I still leave this box ticked for safety. All I have to do is start the charging again and it completes without any issues.

As I understand it, slower charging is better for Lithium batteries, so I don’t stress about getting the last amp of charge current into the battery as long as it’s likely to charge fully before I’m ready to leave the dock again.

 

[ranger58sb]

OK, this feed back suggests there are setting issues. I have both people looking at the Weak AC setting, as well as the charger current limit. It might also be more specific to the large Quattros in this case - 24V/8kw.

I dunno what our MultiPlus is doing yet; haven't really tasked it with much since we've only been on shorepower since installation.

I've read about 3 settings: input current limit, weak current, and default charging level. Of those, latter two seem to be about output.

The default charging level is set at 75% and increasing that to 100% should increase output.

The weak current thing is about sloppy (notionally, generator) input and it derates the system somehow... but could be turned OFF if input is clean. Default is off, I think.

Input current limit seems to be more about matching the system to your shorepower, breakers, and general boat consumption. Our 70A charger -- 7A AC -- doesn't need to draw al that much to work, but apparently inrush (?) current was about 18A so we needed to replace the 20A breaker with a 30A.

-Chris

 

[CMS]

It's right in the manual and can be adjusted..

 

[stevemitchell]

I have two 24v, 5000W, 120VAC Quattro inverters in my engine room that routinely produce over 90% (most of the time higher) of rated charging capacity into a big LiFePO4 battery bank.

I've also designed/installed quite a few more for others and have seen good performance out of the 24v Quattros in all situations. All of those setups were designed around a decent ambient temperature (not right next to something terribly hot, etc.) and with plenty of airflow and space around them.

I've also had a number of installs of MultiPlus and of the 12v Quattro, and some with inadequate airflow, and in all of those, the units would have challenges maintaining high charge rates. Many of them fell below 75% once the temp in the unit got past a certain point.

There are also some bugs/behavior with the MultiPlus that cause it to charge at lower rates due to stupid logic that Victron has put in place that you can fiddle around with to get around.