Need some clarification, not charging to 100%

[YoloSF]

Hello forum,

I'm looking for a better understanding of what I have installed on my boat and how to use it properly:

- Alternators 90A on engine, 60A spare under front bunk
- Solar Panels 2x 100W Solbian flexible SP100L with Blue Sky 2512i charge controller
- Engine Crank battery 1 x 100 amp/hr with charge isolator
- House batteries: 3x 230 AMP/HR Trojan AGM Marine batteries
- Mastervolt MASS 12/80 battery charger
- Mastervolt MASS Sine 12/2000 2kW 220V AC Inverter with C4-RI remote switch
- Mastervolt Battery Monitor BTM remote monitor

I left the boat unplugged with everything turned off for 20 days while I was on vacation. I left at like 60% charge and return to have it at 72% charge. I was expecting with all that time and no consumption it would have charged to 100%. Is there something I need to calibrate? Could it be that the batteries are older and can't fully charge?

I've noticed solar panels vary in price greatly, for a 100W one you can get it for around $150-$1250. What makes a panel worth more or less?

Thanks in advance,
@couchsailors

[sailorchic34]

My first question is how shaded are the panels. Shading of 1/2 of one cell cuts solar output of that panel by roughly 80 ish percent. Were the panels wired series or parallel.

Other possibility, the battery monitor needs calibration.

My two panels (230 watts total) keeps my batteries topped up daily with loads.

I have a cheap Chinese 100 watt panel and a Kyocera 130 watt panel. Only difference I see is that the frame on the cheap panel is thinner gauge and not anodized. Otherwise construction is the same.

[YoloSF]

Originally Posted by sailorchic34

My first question is how shaded are the panels. Shading of 1/2 of one cell cuts solar output of that panel by roughly 80 ish percent. Were the panels wired series or parallel.

Other possibility, the battery monitor needs calibration.

My two panels (230 watts total) keeps my batteries topped up daily with loads.

I have a cheap Chinese 100 watt panel and a Kyocera 130 watt panel. Only difference I see is that the frame on the cheap panel is thinner gauge and not anodized. Otherwise construction is the same.

They're on top of the bimini, but... we are in San Francisco, so we get a lot of fog. I guess I'll have to do some research on how to calibrate the battery monitor then!

[skipmac]

Do not have experience specifically with the Mastervolt battery monitor but I'm pretty certain it works like 99% of the battery monitors and must be programmed and periodically zero'd or synch'd to give reasonably accurate reading.

First step, is the monitor installed correctly so all charge and discharge goes through the monitor. So is this a new install or old? Has it worked correctly in the past or not or don't know? Has the wiring been changed recently? Have you installed more batteries?

Once you sort out all the above, has the monitor been programmed with all the correct information: battery bank capacity, Peukart, etc?

Then, how long since the monitor has been synched to the actual state of charge of the batteries?

[YoloSF]

Originally Posted by sailorchic34

My first question is how shaded are the panels. Shading of 1/2 of one cell cuts solar output of that panel by roughly 80 ish percent. Were the panels wired series or parallel.

Other possibility, the battery monitor needs calibration.

My two panels (230 watts total) keeps my batteries topped up daily with loads.

I have a cheap Chinese 100 watt panel and a Kyocera 130 watt panel. Only difference I see is that the frame on the cheap panel is thinner gauge and not anodized. Otherwise construction is the same.

Just noticed you're in SF too! If you can get your batteries topped daily, so should I!

[YoloSF]

Originally Posted by skipmac

Do not have experience specifically with the Mastervolt battery monitor but I'm pretty certain it works like 99% of the battery monitors and must be programmed and periodically zero'd or synch'd to give reasonably accurate reading.

First step, is the monitor installed correctly so all charge and discharge goes through the monitor. So is this a new install or old? Has it worked correctly in the past or not or don't know? Has the wiring been changed recently? Have you installed more batteries?

Once you sort out all the above, has the monitor been programmed with all the correct information: battery bank capacity, Peukart, etc?

Hi Skipmac, I bought the boat used, but it had lots of bluewater long distance sailing (Signapore to California) so it's an old install, but it worked correctly in the past. I haven't installed more batteries. It looks like I need to calibrate it. I'm not sure how, but I'll find the manual and dig into it a bit more and let you know the results.

Thanks for your help!

[Jim Cate]

Yolo, there is a big diferential in total sunshine hours between different parts of the "SF Bay area". Could be that SailorC hangs out in the sunnier parts... she's free to move about and has good sense, so I bet that's the case!

Jim

[sailorchic34]

LOL, Actually, I'm summering in the California Delta. No fog here and temps in the 80's- 90's.

Personally, on top of the Bimini, to me anyway, is the worst place for solar panels. The boom and mast/rigging will cast shadows on the panels almost all the time. Specially if one is on each side of the boom. One panel will be shaded most of the time.

My panels are off the stern and port rail and each pivot in one plain, and even then I move the boom out beyond the starboard rail at anchor to give as little shading as possible.

[skipmac]

Originally Posted by YoloSF

Hi Skipmac, I bought the boat used, but it had lots of bluewater long distance sailing (Signapore to California) so it's an old install, but it worked correctly in the past. I haven't installed more batteries. It looks like I need to calibrate it. I'm not sure how, but I'll find the manual and dig into it a bit more and let you know the results.

Thanks for your help!

To synch (or calibrate) the monitor with your batteries you need to determine the state of charge. A few ways to do that, some much better than others.

To do this accurately you have to fully charge the batteries, The best way to determine if they are fully charged is to measure the amps in until the batteries will only accept a very small additional charge. I cannot remember without digging out my notes the exact figure but bet Sailorchic knows it off the top of her head.

You can get a rough idea of the SOC by looking at the voltage at rest. Charge up and let the batteries sit for a few hours with no load and no charge and check the voltage. Charged, good batteries should read about 12.6V. NOTE this is approximate and only helps if you have an accurate meter as well.

[djmarchand]

Two thoughts in addition to the good advice above.

Check your boats amperage usage on the monitor with everything off and at night or with your solar panels disconnected. You might have some significant DC load that you don't know about.

Secondly battery charging can be significantly impacted by undersized wiring. You need at a minimum 10 gauge wire from the panels to the controller and if they are more than ten feet away you need 8 gauge wire.

David

[YoloSF]

Originally Posted by skipmac

To synch (or calibrate) the monitor with your batteries you need to determine the state of charge. A few ways to do that, some much better than others.

To do this accurately you have to fully charge the batteries, The best way to determine if they are fully charged is to measure the amps in until the batteries will only accept a very small additional charge. I cannot remember without digging out my notes the exact figure but bet Sailorchic knows it off the top of her head.

You can get a rough idea of the SOC by looking at the voltage at rest. Charge up and let the batteries sit for a few hours with no load and no charge and check the voltage. Charged, good batteries should read about 12.6V. NOTE this is approximate and only helps if you have an accurate meter as well.

I'm waiting on a shore power cable replacement (it's complicated since the boat is 220V...) which will arrive next week. Could I just leave it plugged in and charging for a full day or two without using anything and assume they're fully charged? Otherwise, I'm assuming I need a specific tool to measure the battery voltage which I don't have.

[skipmac]

Originally Posted by YoloSF

I'm waiting on a shore power cable replacement (it's complicated since the boat is 220V...) which will arrive next week. Could I just leave it plugged in and charging for a full day or two without using anything and assume they're fully charged? Otherwise, I'm assuming I need a specific tool to measure the battery voltage which I don't have.

Important question. Is your boat 220V US or European power IE 60 Hz or 50 Hz. If 50 Hz and you are plugging into a marina in the US be very certain that any electrical equipment or appliance is compatible with US power or you're going to make spark and smoke and be buying some new, probably expensive equipment.

The way to determine your batteries are fully charged, assuming they are in good condition is to charge until they are taking no more that 1.5% of the total amp hour capacity of the battery bank at a charge voltage of 14.4V. For your system, 690 ah total according to your original post, that would be less than 10 amps.

[YoloSF]

Originally Posted by skipmac

Important question. Is your boat 220V US or European power IE 60 Hz or 50 Hz. If 50 Hz and you are plugging into a marina in the US be very certain that any electrical equipment or appliance is compatible with US power or you're going to make spark and smoke and be buying some new, probably expensive equipment.

The way to determine your batteries are fully charged, assuming they are in good condition is to charge until they are taking no more that 1.5% of the total amp hour capacity of the battery bank at a charge voltage of 14.4V. For your system, 690 ah total according to your original post, that would be less than 10 amps.

My inverter is 50hz, so 50hz? It's interesting you say this because I"m replacing the power plug because it fried: Finally, a simple fix | COUCH SAILORS I am using an upconverter from 110-220v though.

I realize I'm sounding like a total nob, but I need to learn and prevent further mistakes. Why is the 60/50hz relevant and what can I do about it?

[skipmac]

Originally Posted by YoloSF

My inverter is 50hz, so 50hz? It's interesting you say this because I"m replacing the power plug because it fried: Finally, a simple fix | COUCH SAILORS I am using an upconverter from 110-220v though.

I realize I'm sounding like a total nob, but I need to learn and prevent further mistakes. Why is the 60/50hz relevant and what can I do about it?

OK, if you are not 100% clear on the difference between US and EU power you should get a professional to help out. Otherwize you can be blowing up stuff and it could be dangerous to you and your boat.

Hz is frequency or how many times per second the AC (alternating current) alternates. from plus to minus voltage.

The difference is not just the frequency, 50 Hz vs 60 Hz but the wiring is different. US 240V AC uses 2 hot and one neutral. EU 220V uses 1 hot and 1 neutral. So voltage is close but if you try to connect one to the other incorrectly you will definitely cause problems.

Check the charger specs. Many battery chargers will work on 50Hz or 60Hz. If it won't do then you will not be able to charge from shore power unless you buy a new charger.

[YoloSF]

Originally Posted by skipmac

OK, if you are not 100% clear on the difference between US and EU power you should get a professional to help out. Otherwize you can be blowing up stuff and it could be dangerous to you and your boat.

Hz is frequency or how many times per second the AC (alternating current) alternates. from plus to minus voltage.

The difference is not just the frequency, 50 Hz vs 60 Hz but the wiring is different. US 240V AC uses 2 hot and one neutral. EU 220V uses 1 hot and 1 neutral. So voltage is close but if you try to connect one to the other incorrectly you will definitely cause problems.

Check the charger specs. Many battery chargers will work on 50Hz or 60Hz. If it won't do then you will not be able to charge from shore power unless you buy a new charger.

It's a French made Beneteau, so it's definitely EU 220V! I've tried finding local professionals, but it's really hard to find in the Bay Area. Everyone's booked months out and they charge $120-180/hr!