Is My Victron Multi Dying ?

[Dreaming Yachtsman]

Yachtsman's Dream has a Victron Phoenix Multi 12 volt, 2000 watt, 120 amp, inverter/charger that has performed flawlessly over the past 8 years until a few days ago. The inverter part still works fine so the discussion below pertains only to the charger.

Normally when I start a battery charge with the diesel generator the charger draws about 15 amps 110 VAC input current while in bulk charge mode. As the battery voltage rises of course the input current diminishes. Usually when charging with the diesel generator I terminate the charge when the input current drops to 5-6 amps AC to minimize running the generator engine under very light load. (Because the Victron is connected directly to the battery inside the battery ammeter shunt, I have no indication of DC charge rate.)

Now when charging with the generator, the input current starts out at the normal 15 amps but after only a few minutes, diminishes fairly quickly to about 6 amps long before the battery voltage reaches 13.6, the setpoint for absorption. Also the Victron stays in bulk mode per indicating lights on the front panel even when charging at this very low rate.
Do I have a reason to be concerned?
Is there anything I can do besides take the unit to a shop, if I can find one?
Does anyone know of a place in St. Thomas that can help me?

The Victron web site is not particularly helpful with either troubleshooting guides or dealer/service center locations.

Other potentially pertinent information:
- The boat came out of six months of dry storage two weeks ago during which the batteries were on open circuit and the Victron was off.
- Last week I replaced the previous set of 6 golf cart batteries with new ones . (Perhaps I'm just being paranoid and have not become familiar with the new battery charging behavior.)

The weather is cloudy and misty today so expecting the solar panels will charge the batteries is unrealistic. (I.e. Need help quickly.)

[impi]

You may want to have the software checked out first .... When was it last upgraded?

[impi]

By the way .... If you need help quickly, give Victron in Holland a call ... There is a very bright technician (woman .... Forget her name) ... But they are incredibly good at assisting you ..had a problem with mine ... Software was upgraded ... All sorted!

[Dreaming Yachtsman]

No software updates have been installed. The unit, as far as I know, doesn't have the capability to be connected to a computer to update it.

[impi]

Originally Posted by Dreaming Yachtsman

No software updates have been installed. The unit, as far as I know, doesn't have the capability to be connected to a computer to update it.

Hmmm .. Sorry about that ... I am running the victron 3000/120 units .... Best call Holland if it's urgent ...

[s/v Jedi]

This sound like a problem with wiring or batteries... Might even be safety issue.

This is what to do first and urgently:

Using a decent multi meter (buy one if you don't have it yet):

- measure voltage at the Victron DC output terminals and at the battery terminals while this strange charging is going on.

There is a chance that voltage is lost at a bad contact, corroded crimp etc. This would result n the symptoms described.

ciao!
Nick.

[Captain Bill]

I don't know how your unit is installed, but you might be getting excessive voltage drop through your cable. Where are you measuring your voltage? If you are measuring at the batteries and the charger is measuring internally, a cable problem adding a bit of resistance can make enough of a difference to cause the charger to think the voltage is higher than it really is. The common causes would be a slightly loose connection, a partially broken conductor, or some corrosion. Any of these will usually cause some localized heating where the failure has occured. This heating can be severe and cause a fire hazard if the condition is bad enough. Check your cable for hot spots after/during a charging session. I have personally experienced a couple of times in my 45 years of boating where the crimp on connectors got some corrosion and caused a problem. Once I even melted the wire while starting the engine, fortunately there was nothing flammable nearby.

[s/v Jedi]

Funny how experienced cruisers sound so alike

ciao!
Nick.

[Dreaming Yachtsman]

Good suggestions to check the cables. I thought they all looked good when I reconnected them to the new batteries but will check for hot spots and voltage drop during the next charge.

The sun is poking through so I may not need the generator again for a while.

[Captain Bill]

Originally Posted by s/v Jedi

Funny how experienced cruisers sound so alike

ciao!
Nick.

It's because we've all "been there, broken that".

[motion30]

I would discharge the batteries a bit then test the charger

[Dreaming Yachtsman]

Having thought about this problem overnight, I agreed with Nick on Jedi and Captain Bill that it was most likely a high resistance cable connection since that, besides the batteries, was the only thing in the system that changed. I expected to find one of the terminals heating up, raising its resistance, and causing a large voltage drop between the charger and the battery terminals. Alas, 'twas not so.

Visual Inspection of battery terminals showed that the negative terminal looked fine but that the lug on the positive terminal MAY have been overheated or corroded at some time in the past. I did not remove the lug at that point because I wanted to confirm that as the problem with voltage and hotspot checks recommended by Nick and Bill before changing something in the system. Note that all voltage and amperage values quoted below are approximate since the readings were not all taken simultaneously nor recorded on the spot.

Before pulling the cover off the Victron to access the DC terminals I started a charge with my clamp-on ammeter on the negative lead between the charger and battery. It initially read 75 amps but after a minute or so, gradually but fairly quickly dropped off to 35 amps. Neither + nor - terminal on the battery showed any perceptible temperature increase to touch.

I stopped that charge, removed the cover to the Victron, and started charging again. As before, the initial charge rate was 75 amps. Terminal voltage at the charger was 13.5 VDC. Battery terminal voltage was 13.4 VDC.

Then it became interesting: charging current began to drop. When it was passing through 50 amps, the terminal voltage at the charger was 13.0 VDC and the voltage at the battery was 12.9. Those voltages are consistent with readings on the installed digital voltmeter that I normally use to monitor battery condition. The charger remained in bulk mode the whole time.

Given the consistency between the output voltage on the charger and the terminal voltage at the battery (actual battery post, not the outside of the cable lug), this phenomenon no longer appears to be a high resistance connection at the battery as I had hoped yesterday. It seems too coincidental to have a failure in the charger at the same time as replacing the battery bank, though, so I am at a loss as to what to do next.

Could a problem with temperature compensation cause this big a performance hiccup? My impression is that would only result in a few tenths of a volt difference.

BTW, this morning the toaster ran for about a minute off the inverter with no problem.

[s/v Jedi]

Hmm Mark on Reach is having similar trouble. I hope it's not a bad production run....

okay, do a full reset which means cut both AC & DC for 5 minutes, then try again.

Also, remove temperature sender and voltage sense wires. Disable "weak AC" and "battery safe" settings. Confirm correct battery type settings.

cheers,
Nick.

[FlyingCloud1937]

Originally Posted by Dreaming Yachtsman

Having thought about this problem overnight, I agreed with Nick on Jedi and Captain Bill that it was most likely a high resistance cable connection since that, besides the batteries, was the only thing in the system that changed. I expected to find one of the terminals heating up, raising its resistance, and causing a large voltage drop between the charger and the battery terminals. Alas, 'twas not so.

Visual Inspection of battery terminals showed that the negative terminal looked fine but that the lug on the positive terminal MAY have been overheated or corroded at some time in the past. I did not remove the lug at that point because I wanted to confirm that as the problem with voltage and hotspot checks recommended by Nick and Bill before changing something in the system. Note that all voltage and amperage values quoted below are approximate since the readings were not all taken simultaneously nor recorded on the spot.

Before pulling the cover off the Victron to access the DC terminals I started a charge with my clamp-on ammeter on the negative lead between the charger and battery. It initially read 75 amps but after a minute or so, gradually but fairly quickly dropped off to 35 amps. Neither + nor - terminal on the battery showed any perceptible temperature increase to touch.

I stopped that charge, removed the cover to the Victron, and started charging again. As before, the initial charge rate was 75 amps. Terminal voltage at the charger was 13.5 VDC. Battery terminal voltage was 13.4 VDC.

Then it became interesting: charging current began to drop. When it was passing through 50 amps, the terminal voltage at the charger was 13.0 VDC and the voltage at the battery was 12.9. Those voltages are consistent with readings on the installed digital voltmeter that I normally use to monitor battery condition. The charger remained in bulk mode the whole time.

Given the consistency between the output voltage on the charger and the terminal voltage at the battery (actual battery post, not the outside of the cable lug), this phenomenon no longer appears to be a high resistance connection at the battery as I had hoped yesterday. It seems too coincidental to have a failure in the charger at the same time as replacing the battery bank, though, so I am at a loss as to what to do next.

Could a problem with temperature compensation cause this big a performance hiccup? My impression is that would only result in a few tenths of a volt difference.

BTW, this morning the toaster ran for about a minute off the inverter with no problem.

How far did you discharge the battery before you started the charge regime?

You said the only thing that has changed is the batteries. If they are fully charged or even charged above 80% SOC I would expect the charger to act the same, as you state.

What is the resting voltage of the battery bank after 24 hrs no charge or discharge for that 24 hr period.

A new battery has a higher internal resistance until it's be cycled at least 20-30 times, and Trojan says their bats take a 100 cycle to reach full potential.

Lloyd

[Dreaming Yachtsman]

Nick,
This unit has no voltage sense lead since the total cable run is only about two meters.

Couldn't find settings for "Weak AC" or "Battery Safe" in installation manual (http://www.victronenergy.com/Manuals...4000-rev08.pdf). The closest to "weak AC" is "PowerControl – Dealing with limited generator or shore side power" on page 16 of that manual. However, that setting is not applicable to the straight up Multi I have since it is a feature in the MultiPlus model.

Temperature sensor is disconnected from the unit.

Did "power off reset" you described. Will try another charge tomorrow morning.

+++++++++++++++
Lloyd,
The batteries were down to 12.15 volts this morning when I started this troubleshooting.

Allowing the batteries to rest for 24 hours is not an options since I am at anchor in St. Thomas and won't be to a dock for over 2 weeks.

Are you telling me that basically there is no problem with these new batteries and that after a break in period the charging pattern will return to normal? I sure hope you are right!