FireFly Battery Operational User Notes

[sailorboy1]

I have my solar controller absorption set for 4 hours or 10 amps at 14.4V. The 10 amps works out to about 1% C20 and a 5 amp house load (the normal with frig and stereo on). Today it switched to float after about 1.5 hours at 1.4V absorption. I wasn't watching as I was working on another project, but the last I checked the battery monitor was reading SOC 98.6% SOC and the SOC by amp-hour math was 98.3% and the batteries were accepting 1.3% of C20. So I feel my CEF of 88% works pretty well at the close to fully charged conditions.

[kmacdonald]

Originally Posted by Panope

Thanks Rick (and others),

If I switch to Firefly, I am willing to buy a new solar controller but that is it. There will be no battery monitor, No adjustable alternator regulator (keep stock Hitachi), No battery charger (no shore power) (when the boat is in the shed during the winter, I occasionally charge with an automotive charger).

I will be willing to educate myself as to the initial set-up of the solar controller but I can promise that I will quickly forget the details of the set-up.

If my alternator's output voltage is too high for Firefly, I will be willing to isolate the house bank (flip a switch) during long motor passages. I will remember to do this most of the time.

The flooded batteries (Dyno) that I have now, have lasted 9 years. I am reasonably certain they have never been below 50% DOD. I have ran the engine for the purpose of battery charging 1 time during this 9 year period.

The simple solution for my battery replacement is just get another set of Dyno flooded batteries as they have worked flawlessly for 9 years.

The reason for switching to Firefly is to be able (in theory) to go with a smaller bank (1 group 31 Firefly replaces 2 group 31 flooded). This assumes the Firefly will tolerate an occasional dip bellow 50% DOD.

Does that sound workable?

That's the way I do things. Simple.
Get two golf cart batteries from Sams Club for $90/each and you're good for 10 years and have plenty of extra capacity too boot.

[kmacdonald]

Originally Posted by Panope

The 2 FLA bank is now larger than I need as I recently ditched the Engel cooler and converted my small and super insulated ice box to 12V. Refrigeration is now consuming only 16 AH per day.


Steve

How big and how much insulation in the frig? What refrig compressor? What's the ambient temp? 16 Ah is great!

[sailorboy1]

Lets try to not drift off the topic

[kmacdonald]

Originally Posted by sailorboy1

Lets try to not drift off the topic

Are you serious?

[docrn]

I’ve learned quite a bit from this thread. Thank you for posting it.

I have 3 FF’s G31’s and just installed 600 watts of solar. Using the Victron BMV712 Smart and 3 Victron smart controllers (100/20’s). Anyway, I set my parameters as below (I could not load pics). The thing that freaks me out is my temp says -1C and my history shows a max battery voltage of 20.34 for the main bank and 21.02 for the starter. This can’t be good or am I just missing something? Can some please critique my situation? Worried I’ll fry those 4y/o FF’s.

BMV712 smart settings....
Battery capacity 330 amp hours
Charge voltage 12.9 V
Discharge floor 50%
Tail current 1.5%
Charged detection time 10 minutes
Puekert exponent 1.07
Charge efficiency Factor 90%
Current threshold 0.10

Relay is in charger mode but I haven’t changed any of the settings. I’m not sure what they should be exactly.

Victron MPPT 100/20 smart controller settings as follows...
Battery voltage 12 V
Battery preset (user defined)
Absorption voltage 14.40 V
Float voltage 13.40 V
Equalization voltage 14.40 V
Automatic equalization set for every 30 days
Temperature compensation 13.33 mV/C
Low temperature cut off is disable

Load up put operation mode is set for battery life

[kmacdonald]

Yep, you are misreading something. If you have a 20.34 volt reading on the main 12 volt battery your panels must be hooked up straight to the battery. If you getting that 20.34 figure from the charge controller it must be the panel voltage, not the battery voltage. Take a look at it and let us know what's really happening. Do you have the battery temp sensor?

[kmacdonald]

docrn, your temp compensation value is wrong. It should be a negative value.

[mitiempo]

Originally Posted by docrn

I’ve learned quite a bit from this thread. Thank you for posting it.

I have 3 FF’s G31’s and just installed 600 watts of solar. Using the Victron BMV712 Smart and 3 Victron smart controllers (100/20’s). Anyway, I set my parameters as below (I could not load pics). The thing that freaks me out is my temp says -1C and my history shows a max battery voltage of 20.34 for the main bank and 21.02 for the starter. This can’t be good or am I just missing something? Can some please critique my situation? Worried I’ll fry those 4y/o FF’s.

BMV712 smart settings....
Battery capacity 330 amp hours
Charge voltage 12.9 V
Discharge floor 50%
Tail current 1.5%
Charged detection time 10 minutes
Puekert exponent 1.07
Charge efficiency Factor 90%
Current threshold 0.10

Relay is in charger mode but I haven’t changed any of the settings. I’m not sure what they should be exactly.

Victron MPPT 100/20 smart controller settings as follows...
Battery voltage 12 V
Battery preset (user defined)
Absorption voltage 14.40 V
Float voltage 13.40 V
Equalization voltage 14.40 V
Automatic equalization set for every 30 days
Temperature compensation 13.33 mV/C
Low temperature cut off is disable

Load up put operation mode is set for battery life

Sounds to me that you may have mis-wired something when you installed the solar. Do you have a diagram of the current wiring of solar controllers and monitor shunt?

[docrn]

Thanks for the responses!

Panels are going to the controllers and the controllers are going to a fuse block then positive direct to battery and negative to Victron shunt (both via gauge 6 wires and fused on the positive side). Everything is going through the Victron controllers. I’m pretty certain we’re good on the wiring. I’m leaning heavily toward a temp compensation issue.

I thought there was a temp sensor in the charge controllers but I also thought there was a temp sensor to the batteries from the Victron shunt. I just looked and think the temp sensor is wired to the start battery (or it’s voltage for the start battery).

Also looked through my pile of stuff and found a Victron temp sensor in a package. Again, wondering if the sensor going to the start battery is voltage but the start battery also runs the house bank unless I switch it off. Not sure if it’s a Beneteau thing or what. Other boats I’ve had are completely separate banks. Also I thought the 712 had a temp sensor built that came with it but this was not in the package. Also worthy of note is the monitor at the nav station for the 712 smart reads “INF C” which leads me to think I don’t have a temp sensor hooked up AND my temp compensation is set wrong.

Hope this doesn’t confuse thing further. Even though I’m an ale true radio guy my knowledge of this stuff is pretty basic but I’m trying to learn as much as I can. Thank you.

[mitiempo]

Originally Posted by docrn

Thanks for the responses!

Panels are going to the controllers and the controllers are going to a fuse block then positive direct to battery and negative to Victron shunt (both via gauge 6 wires and fused on the positive side). Everything is going through the Victron controllers. I’m pretty certain we’re good on the wiring. I’m leaning heavily toward a temp compensation issue.

I thought there was a temp sensor in the charge controllers but I also thought there was a temp sensor to the batteries from the Victron shunt. I just looked and think the temp sensor is wired to the start battery (or it’s voltage for the start battery).

Also looked through my pile of stuff and found a Victron temp sensor in a package. Again, wondering if the sensor going to the start battery is voltage but the start battery also runs the house bank unless I switch it off. Not sure if it’s a Beneteau thing or what. Other boats I’ve had are completely separate banks. Also I thought the 712 had a temp sensor built that came with it but this was not in the package. Also worthy of note is the monitor at the nav station for the 712 smart reads “INF C” which leads me to think I don’t have a temp sensor hooked up AND my temp compensation is set wrong.

Hope this doesn’t confuse thing further. Even though I’m an ale true radio guy my knowledge of this stuff is pretty basic but I’m trying to learn as much as I can. Thank you.

Victron solar controllers sense temp internally unless you purchase optional bluetooth temp sensor.

Victron BMV-712 temp sensor is optional. It plugs into the shunt with a next to the output for the display unit. The other end goes to a negative post determined to be the warmest battery - typically the middle of the bank.

The red wire going to the start battery positive is for voltage of start battery only. The other red wire from the shunt goes to either the house battery positive or the bus wired directly to house battery positive.

What do you mean "the start battery runs the house bank"? please explain.

Is the shunt the first item after the house bank's negative post without any other connections at the negative post?

I don't think setting the temp compensation incorrectly could lead to such an error.

Do you have a multi-meter? If so I would measure the batteries directly to confirm the readings are correct.

[docrn]

Thank you.

My engine start battery (also a FF) also runs the house bank if the switch is on. I can then turn off the main bank and everything in the boat runs.

Here’s a pic of the shunt. It looks like it’s only voltage sensors connected (one to both banks). . I‘m uncertain where the temp sensor might plug in to.

https://drive.google.com/file/d/1P9H...w?usp=drivesdk

Is the shunt the first item after the house bank's negative post without any other connections at the negative post? Yes. The wire on the right in that pic is coming from the house bank. The wires on the left are the where I connected the negative from the panels and what I assumed was the lead to the panel. I now think the big wire on the left is actually the negative for the start battery and I should have just connected the negative from the charge controllers to the shunt that the negative from the batteries (wire on the right) is connected to. Is this making sense?

[docrn]

Originally Posted by docrn

The wires on the left are the where I connected the negative from the panels and what I assumed was the lead to the panel. I now think the big wire on the left is actually the negative for the start battery and I should have just connected the negative from the charge controllers to the shunt that the negative from the batteries (wire on the right) is connected to. Is this making sense?

Disregard the part above. I forgot about the crazy Beneteau common negative switch. That is where the big wire connected to the load side of the shunt is going which I suppose is ultimately connected to the negative start battery as it looks like they all go to the same common ground via a switch (much like the one pictured below). It’s impossible to trace the wires in this boat.

In any case I feel I’m taking this thread off course and away from the original intent of the OP. Can someone tell me the correct coefficient and temp compensation numbers for the FF so I can enter them into the parameters for the CC’s? I’ll remove the voltage sensor for the start battery and wire up the temp sensor and see if that helps.



Thanks again.

[mitiempo]

Originally Posted by docrn

Thank you.

My engine start battery (also a FF) also runs the house bank if the switch is on.


The wire on the right in that pic is coming from the house bank. The wires on the left are the where I connected the negative from the panels and what I assumed was the lead to the panel. I now think the big wire on the left is actually the negative for the start battery and I should have just connected the negative from the charge controllers to the shunt that the negative from the batteries (wire on the right) is connected to. Is this making sense?

The start battery runs the loads if the loads, not the house bank.

D o not connect solar negative on the right as then solar would not be counted. All charging and loads have to be connected AFTER the shunt.

https://www.victronenergy.com/upload...tion-guide.pdf

Temp sensor is #13

[docrn]

Thanks Miltiempo

I almost had myself convinced I wired it wrong.