Victron 100/30 voltage measurement

[john61ct]

In that context, erring on the high side at least for the solar, will be better than below spec.

When wind charging is constant, will want to back it off a bit.

[mitiempo]

Originally Posted by snotter

I had the exact same nuisance problem with both of my 100/30’s. I chalked it up to Victron economizing on quality control. My logic was why would Victron want to spend the money the money on lab grade accuracy on a relatively cheap controller that should be user set up. I upped the voltage and measured output at the battery. I set absorption and float voltage to the published values that Trojan specify for my T1275’s. After a year my batteries seem happy. They never seem to need water. However, in hot or cold weather I rely on my sterling shore charger because they are temperature monitored.

Your Victron controllers can be temperature monitored as well.
https://www.victronenergy.com/blog/2...olar-chargers/

[Paul L]

Originally Posted by mitiempo

Your Victron controllers can be temperature monitored as well.
https://www.victronenergy.com/blog/2...olar-chargers/

And certainly should be if we are worrying about this level of calibration. The correct absorption voltage is more than a few tenths difference for temperature changes between the tropics and Tasmanian.

[FlyingScot]

Just to be clear on my position. Your meter may be wrong or right. The Victron reading may be wrong or right. You have to decide which horse to bet on if you don't wan't to really find out.
You think your meter is correct, and I tend to agree with you, then I would adjust the MPPT to output what your meter says is correct at the battery. What the MPPT thinks is meaningless. You adjust the settings until your meter on the battery is right.
This may not 'feel' right in your gut, but I question why? This isn't lab grade equipment or pricing. You adjust the settings until the measurements at the battery are to your satisfaction.

Admittedly, it would be easier if you could just program the numbers and walk away.

I had to turn all my 100/30's down by 0.2v to prevent too much voltage reaching the battery when they were almost full. I'll test again this week with a calibrated meter.

[hzcruiser]

Originally Posted by Jim Cate

I'll keep casting about for a lab quality meter or standard... one never knows what one will find in the cruising fleet.

Meanwhile, I'll leave the Victron with manually selected voltages that provide the correct battery values.

Jim

Hello Jim,


even though a lot of Victrons seem to be spot yours might be the odd one out, of course.
With two handhelds agreeing on a voltage this seems to be the case after all.



If you want I can come over with some of my handheld meters that I just compared to my bench DMM and see if your meters agree with them:



12.000V on the Agilent 3401 bench meter:

ST&T el cheapo: 11.99 V (occassionally jumping to 12.00V)
Fluke 73: 11.99V
CMS 830B (super cheap meter): 12.00V
Voltcraft M818 (about 20 years old): 11.99V (occ. 11.98V)

[thomm225]

Originally Posted by Jim Cate

Since you are a highly trained marine electrician what do you think is the result, long term, of having an absorption voltage of 14.6 instead of the 14.8 specified by Trojan? And a float voltage similarly low?

Some folks believe that such undercharging will be detrimental to battery life. I am one of them. What say you, Thomm?

Jim

I'm not a highly trained marine technician. I'm a highly trained electronics technician (and I majored in the History of Technology). The electrical/batteries etc are just a natural extension of that training which you have to know anyway since you/we have large UPS Units with 24/48 batteries and electrical power (usually three phase, 60 HZ or three phase 400 HZ) hooked up to all our Radar's, simulators etc. Some parts of the simulators have Aircraft Common Equipment (ACE) so you need the three phase 400 Hz for that.

I say I doubt it's a problem, but if it worries you adjust your Victron up a bit if possible. I've made no adjustments to my Victron yet. I'm still at the defaults

But you might first want to check your voltages with a calibrated Fluke Meter. Don't depend on the monitoring app. for correct voltage readings

Personnally though I don't worry about being off by .2 of a volt because it could be so many different small things which is why I don't have a calibrated meter onboard and haven't borrowed one from work. Usually ball park is good enough

Now if your chronometer is off by a few seconds each day and you are navigating by sextant, you then have a real problem.

Tom

[Jim Cate]

Originally Posted by hzcruiser

Hello Jim,


even though a lot of Victrons seem to be spot yours might be the odd one out, of course.
With two handhelds agreeing on a voltage this seems to be the case after all.



If you want I can come over with some of my handheld meters that I just compared to my bench DMM and see if your meters agree with them:



12.000V on the Agilent 3401 bench meter:

ST&T el cheapo: 11.99 V (occassionally jumping to 12.00V)
Fluke 73: 11.99V
CMS 830B (super cheap meter): 12.00V
Voltcraft M818 (about 20 years old): 11.99V (occ. 11.98V)

Heinz, that is a very kind offer! Where are you located? It could work either way... I could just bring my DVM and compare readings with any of yours, and that would verify or un-verify my accuracy.

Jim

[thomm225]

Originally Posted by hzcruiser

Hello Jim,

even though a lot of Victrons seem to be spot yours might be the odd one out, of course.
With two handhelds agreeing on a voltage this seems to be the case after all.

If you want I can come over with some of my handheld meters that I just compared to my bench DMM and see if your meters agree with them:

12.000V on the Agilent 3401 bench meter:

ST&T el cheapo: 11.99 V (occassionally jumping to 12.00V)
Fluke 73: 11.99V
CMS 830B (super cheap meter): 12.00V
Voltcraft M818 (about 20 years old): 11.99V (occ. 11.98V)

I doubt his is the odd one out. Even on this thread, others besides myself have had similar problems.

It's probably the app for the monitor.

Folks simply need to chill out on a .2 volt difference even though that may be the only concern of the day anchored or docked when retired on a sailboat.

It's best to try not to let your world close in on you so much that you are worrying about a .2 volt difference on your batteries, but unfortunately that's what we do when we get old.

Get off my yard you rotten kids! Even though the grass will grow back regardless....

[john61ct]

It really is not appropriate for members to denigrate others just because they choose to be more precise in their requirements.

> For those who see these issues only as means to an end, then they should definitely make their own judgment calls about how close to the ideal is "good enough".

[Jim Cate]

Originally Posted by thomm225

I doubt his is the odd one out. Even on this thread, others besides myself have had similar problems.

It's probably the app for the monitor.

Folks simply need to chill out on a .2 volt difference even though that may be the only concern of the day anchored or docked when retired on a sailboat.

It's best to try not to let your world close in on you so much that you are worrying about a .2 volt difference on your batteries, but unfortunately that's what we do when we get old.

Get off my yard you rotten kids! Even though the grass will grow back regardless....

Thomm, I'm very impressed with your wisdom. I wish I was as young and smart as you are.

Sadly, I'm old and obsessed with my batteries, so I'll just go on trying to treat them the way Trojan says is correct.

Jim

[FlyingScot]

I brought my new NIST calibrated Fluke 87v and compared it to my BMV-712. My BMV-712 is 0.03 different than my Fluke.
Fluke 87v: 12.68 v
BMV-712: 12.65 v
$13 special: 12.68 v

All meter readings taken directly at the battery posts.

If anyone is in Curaçao and wants to compare meter readings, I’d be happy to do so.

[thomm225]

Originally Posted by Jim Cate

Thomm, I'm very impressed with your wisdom. I wish I was as young and smart as you are.

Sadly, I'm old and obsessed with my batteries, so I'll just go on trying to treat them the way Trojan says is correct.

Jim

Thanks for the compliment Jim. Maybe in your next life you can be more like me.

If you want to obsess over your .2 volt difference from what Trojan says it should be that's great, but remember it could be so many other small things. Your meter isn't even calibrated!

It's simply not a big deal, but as we all know here on CF every small thing seems to become a big deal.

As I said before, it has to do with your world shrinking just worrying over your boat and it's systems.

[Jim Cate]

Maybe in your next life you can be more like me.

I hope that my sins have not been that bad...

Jim

[thomm225]

Originally Posted by Jim Cate

I hope that my sins have not been that bad...

Jim

Yeah, hopefully not......

[evm1024]

Let's see. 0.2 volts is 200 mV and the difference between charging my LiFePO4 batteries to 13.6 volts or 14.0 volts with a target of 13.8 volt.

Big difference - likely not. But still significant for LiFePO4.