400: GEL battery question

[arsenelupiga]

I am trying to understand my original battery setup on L 400.

Have 4 exide 120 AH, total 480 AH
Have 2 solar total 360 W

Boat now 3.5 year old and purchased second hand.

MAstervolt monitor displayed this info:
Total capacity 120AH, trickle starts at 80%, alarm at 35% which totals 78 AH usable.
Setup appears original. All works fine.

That means that I only have 16% of my capacity usable.

Any ideas why this type of parameters ? I expected 480 AH capacity and ~ 30% of that usable which is 144 AH, based on what I have read in CF and elsewhere.

[tuskie]

I doubt that the Mastervolt battery monitor is original factory fit. L400s usually only come with the Scheiber panel displaying voltages and amperes being used.

Easy (for a tech savvy guy like you!) to reprogram the BMS and change those parameters. The tricky number is the actual Amp Hour capacity of your bank. Your batteries started out with 480 AH but the capacity diminishes over time. Solar input is irrelevant, the BMS basically counts AHs out and in to the bank, monitors voltages and sounds alarms as programmed.

This may assist:
Keeping Your Battery Monitor More Accurate Photo Gallery by Compass Marine How To at pbase.com

[smac999]

your battery montitor should be set to 480ah. (assuming all 4 are in one bank) do you have a 5th start battery?

then you can draw to -240ah which is 50%. (or maybe lower with gel)

if the voltage is below 12v before you reach -240ah then the batteries are weak.

[tuskie]

Originally Posted by smac999

your battery montitor should be set to 480ah. (assuming all 4 are in one bank) do you have a 5th start battery?

then you can draw to -240ah which is 50%. (or maybe lower with gel)

if the voltage is below 12v before you reach -240ah then the batteries are weak.

A 5th and a 6th start battery. (This is the Lagoon catamaran section.) But what's that got to do with it?

I disagree with using the "sticker value" (480 AH) for the 3.5 year old Gels, and according to the article in the link I posted, so does Compass Marine.

If you wish for any sort of longevity, I would definitely NOT advise drawing 240 AH (ie. 50%) out of the old house bank, as you suggest.

[arsenelupiga]

thanks tuskie, very useful. Will have to read again.

yup, you are right, solars & mastervolt are not lagoon installation.

We are modest users of electricity. 78 AH for night seem a lot to us. Only 1 fridge. I dont think we have passed 50 AH used overnight. But this will likely change.

Will have to observe AP usage. Ignored electricity setup until now.

As previous owner of the boat is very knowledgeable guy, hesitant to change anything until understanding the whole picture.

Lagoon manual says one should not draw below 80% which means 20% usable or 96 AH. So 78 AH not that far off. Motor can replace 40 AH say in 1.5 hour, and then you get to trickle mode where is no point charging.

[tuskie]

Yes, every boat is different as far as energy budgets go, so the battery bank size and type, charging systems, inverters, etc. will vary accordingly. It would be good to not have to use your motors to charge batteries.

We carefully researched our needs and constructed a very suitable system that works great, except when we do big sailing days! Especially if we sail north. As we are in the southern hemisphere, the sails shade our solar panels and the boat becomes much more power hungry than at anchor. The AP and electronics use more than we predicted. We get very little increase in charge percentage during these sailing days, then after dark the bank goes down quite quickly, due to zero charging input and the extra load from radar and lights. So on longer passages, we either start the genset or a motor before dawn. Perhaps a wind generator would solve our deficiency, but I'm not sure.

The take home message is that you can't have too much power.

[BambooSailor]

My Lagoon came with same Mastervolt battery monitor settings, these appear to be be defaults from factory. I have to change them after delivery to reflect actual setup. Have you already try to change these setting? If so, were you required to enter password and did you receive warning about invalidating warranty?

[meirriba]

Originally Posted by arsenelupiga

I am trying to understand my original battery setup on L 400.

Have 4 exide 120 AH, total 480 AH
Have 2 solar total 360 W

Boat now 3.5 year old and purchased second hand.

MAstervolt monitor displayed this info:
Total capacity 120AH, trickle starts at 80%, alarm at 35% which totals 78 AH usable.
Setup appears original. All works fine.

That means that I only have 16% of my capacity usable.

Any ideas why this type of parameters ? I expected 480 AH capacity and ~ 30% of that usable which is 144 AH, based on what I have read in CF and elsewhere.

You need to re-program the MasterVolt monitor.
What type is it?
We have Mastervieweasy MkII Monitor. It allows for separate monitoring of several banks (or 'suppliers' like your solar panels).
Each monitored entity requires its own shunt (expensive piece of hardware).
To change the settings for specific monitored entity you need to enter the 'MV Easy' link on the monitor and enable configuration (normally the configuration is disabled to protect against random changes)

[arsenelupiga]

As bamboosailor said, settings are locked and it says change invalidates warranty.

I have not tried to break in yet. There must be reason for these settings i am trying to understand.

[arsenelupiga]

Originally Posted by BambooSailor

My Lagoon came with same Mastervolt battery monitor settings, these appear to be be defaults from factory. I have to change them after delivery to reflect actual setup. Have you already try to change these setting? If so, were you required to enter password and did you receive warning about invalidating warranty?

did you order solar installation from lagoon or after market ?

[meirriba]

Originally Posted by arsenelupiga

As bamboosailor said, settings are locked and it says change invalidates warranty.

I have not tried to break in yet. There must be reason for these settings i am trying to understand.

You may always pay MV tech rep for the amendment of the original settings that were not properly set at the installation.
Attached is MV instructions how to do the setup.
I just did the setting for new set of batteries last month.

[arsenelupiga]

Originally Posted by meirriba

You may always pay MV tech rep for the amendment of the original settings that were not properly set at the installation.
Attached is MV instructions how to do the setup.
I just did the setting for new set of batteries last month.

thanks a lot for clarifying Big step for me in electricity world.

Next thing I have to figure out if BMS is only monitoring tool or has power to stop charging process when 100% by stopping electric flow in charging direction.

[2Wind]

Originally Posted by arsenelupiga

Next thing I have to figure out if BMS is only monitoring tool or has power to stop charging process when 100% by stopping electric flow in charging direction.

Forgive me if I'm saying the obvious to you....

The usual setup would include a photovoltaic battery charge controller eg. Solar Boost etc. hopefully with Maximum Power Point Tracking which provides the programming for bulk, acceptance and float voltages and charge duration in acceptance mode. This will be separate from your AC battery charger used at the dock. If you can't find it just track the high voltage cables from the solar panels.

The MasterVolt, just counts amps, that's it. Often not that well as there are assumptions in its algorithm that may or may not be true. It's generally good and reliable for a number of cycles but after a week you will see inaccuracies sorted by a reset if you are very sure you are fully charged or after a 24hrs on the AC charger. Changing the battery capacity figure to relect what is actually installed clearly is required for it to be of any real use so you must do that....

Once you know your Acceptance and float charge voltages and watch the voltmeter, you will see when the system shifts to float when you can be fairly sure that the batteries will be near 95%. Most LA or Gel systems will move from bulk to acceptance at about 70-75% and from acceptance to float at 95%.

Personally to look at the percentace charges readout beacuse it is easy and quick, but in reality if I am really interested, I watch the voltages.

For Gels, your acceptance voltage will be set near 14.4V usually for 2-3 hours with float being 13.2-13.4V or there abouts depending on the battery manufacturer's recommendations.

Also be watching the voltages when under load as opposed to charging as these are what really matters. 80% is going to be about 12.5V, 70% about 12.37V, 60% 12.24V and 50% 12.1V. Best not to go below 60% often, and 50% never/rarely. The rate of drain will tell you about the health of your batteries..

Cheers.

[arsenelupiga]

Originally Posted by 2Wind

Forgive me if I'm saying the obvious to you....

The usual setup would include a photovoltaic battery charge controller eg. Solar Boost etc. hopefully with Maximum Power Point Tracking which provides the programming for bulk, acceptance and float voltages and charge duration in acceptance mode. This will be separate from your AC battery charger used at the dock. If you can't find it just track the high voltage cables from the solar panels.

The MasterVolt, just counts amps, that's it. Often not that well as there are assumptions in its algorithm that may or may not be true. It's generally good and reliable for a number of cycles but after a week you will see inaccuracies sorted by a reset if you are very sure you are fully charged or after a 24hrs on the AC charger. Changing the battery capacity figure to relect what is actually installed clearly is required for it to be of any real use so you must do that....

Once you know your Acceptance and float charge voltages and watch the voltmeter, you will see when the system shifts to float when you can be fairly sure that the batteries will be near 95%. Most LA or Gel systems will move from bulk to acceptance at about 70-75% and from acceptance to float at 95%.

Personally to look at the percentace charges readout beacuse it is easy and quick, but in reality if I am really interested, I watch the voltages.

For Gels, your acceptance voltage will be set near 14.4V usually for 2-3 hours with float being 13.2-13.4V or there abouts depending on the battery manufacturer's recommendations.

Also be watching the voltages when under load as opposed to charging as these are what really matters. 80% is going to be about 12.5V, 70% about 12.37V, 60% 12.24V and 50% 12.1V. Best not to go below 60% often, and 50% never/rarely. The rate of drain will tell you about the health of your batteries..

Cheers.

you got my level of expertise with electric system right Thanks for overview.

Just checked exide batteries docs and see now what should I look for.

12.6 V for exide gel means 60% full, 12.9 means 90% full. I will determine 90 % full by watching voltage when no current. When 12.9, means I have used 10 % of capacity, checked AH used and so estimate actual capacity of 4 x 120 AH batteries.

Exide batteries should not be discharged below 80% for max longevity, meaning I have 96 AH for overnight, assuming capacity = nominal capacity, which is not the case for 3.5 years old batteries.

Have victron controller, and presume is smart enough to know when battery is full.

Plenty to check next weekend

[arsenelupiga]

Here is what i found this weekend armed with additional knowledge from this forum:

We have 78 AH usable. Time remaining is currently set to target 25 % discharge (as 120 AH capacity entered) This appears more than enough. All kitchen lights on (2x) eats 3 Amp. Say 5 hours night time costs 15AH. Still left with 63 AH which I have no idea how to use during night.

In sydney winter, my adjustable 360 W solars produce 16 amp which on sunny day is enough.

All batteries voltages appear as per manufacturer instructions and are in line with what MasterVolt shows.

I have not done true O/N sailing so will wait for that, but for what we do - coastal sailing, appears energy needs are fully covered and no need to change.

So jury still out there if i need to upgrade solar, even with watermaker. Washing machine & microwave is not on must have list.

This is for when switch to full time.