Best practice for desulfation battery bank

[phantomracer]

Originally Posted by Maine Sail

Part of the problem with the Efoy is it uses an old school ON/OFF rather "dumb", if you will, charge protocol as it ships from the factory..

It allows the battery to discharge to approx 12.3V then it turns on and brings the bank to 14.2V. At 14.2V it then shuts off and lets the battery voltage decay to 12.3V again before it turns on again..

This is simply not a healthy charge algorithm for lead acid batteries as it does not hold a proper absorption voltage time and does not hold the battery at "full" because it is allowing it to "cycle" or drop to somewhere around 60-65% SOC before turning on again. You are essentially PSOC (partial state of charge) cycling the bank every day...

If the ON point is bumped to 12.9V to 13.0V the battery would remain fuller but the Efoy would have shorter run-time cycles and I am unsure if this is "recommended".

The ON/OFF parameters on the Efoy can be changed but this requires Efoy software and a computer. Best to consult with Efoy on this and specifically ask about what impact any short-cycling will have on the longevity of the unit. A 13.0V ON point is much better for the batteries as you are not using their capacity but it would create a very short run time back to 14.2V and this I am unsure of as to the health of the Efoy. I've quoted a number of them and done the research but not yet installed one. One of my main frustrations is the charge algorithm which is really old school...

The Efoy is really not a charger as it ships because it uses your batteries for about 35% of their capacity before bringing them back to 14.2V and shutting off again. A battery charger would maintain them at full and the battery charger would supply the needed power when plugged in...

awesome. thank for the explanation. what is the solution? adjusting the settings on the fuel cell? I have the programmer and a dedicated laptop that I am bringing to the boat tomorrow to play with it.

i have an updater coming from efoy to update the programming of the unit as well.

although it isnt perfect, it is better than solar..as my battery bank would be flat after a day or 2 at anchor with everything running (laptop charger, lights, fridge, anchor light, radio, etc)

and again.. would equalizing the batteries be a good thing if i can get to a dock for a while to get shore power

[phantomracer]

Originally Posted by Maine Sail

Part of the problem with the Efoy is it uses an old school ON/OFF rather "dumb", if you will, charge protocol as it ships from the factory..

It allows the battery to discharge to approx 12.3V then it turns on and brings the bank to 14.2V. At 14.2V it then shuts off and lets the battery voltage decay to 12.3V again before it turns on again..

This is simply not a healthy charge algorithm for lead acid batteries as it does not hold a proper absorption voltage time and does not hold the battery at "full" because it is allowing it to "cycle" or drop to somewhere around 60-65% SOC before turning on again. You are essentially PSOC (partial state of charge) cycling the bank every day...

If the ON point is bumped to 12.9V to 13.0V the battery would remain fuller but the Efoy would have shorter run-time cycles and I am unsure if this is "recommended".

The ON/OFF parameters on the Efoy can be changed but this requires Efoy software and a computer. Best to consult with Efoy on this and specifically ask about what impact any short-cycling will have on the longevity of the unit. A 13.0V ON point is much better for the batteries as you are not using their capacity but it would create a very short run time back to 14.2V and this I am unsure of as to the health of the Efoy. I've quoted a number of them and done the research but not yet installed one. One of my main frustrations is the charge algorithm which is really old school...

The Efoy is really not a charger as it ships because it uses your batteries for about 35% of their capacity before bringing them back to 14.2V and shutting off again. A battery charger would maintain them at full and the battery charger would supply the needed power when plugged in...

If I were solar only, wouldn't this still be the case..get charged during the day (providing it was sunny)..and i hit it hard at night with a lot of use (computer, fridge, radio, lights, etc) bringing the voltage down to a low level?

[Maine Sail]

Originally Posted by phantomracer

awesome. thank for the explanation. what is the solution? adjusting the settings on the fuel cell? I have the programmer and a dedicated laptop that I am bringing to the boat tomorrow to play with it.

i have an updater coming from efoy to update the programming of the unit as well.

although it isnt perfect, it is better than solar..as my battery bank would be flat after a day or 2 at anchor with everything running (laptop charger, lights, fridge, anchor light, radio, etc)

and again.. would equalizing the batteries be a good thing if i can get to a dock for a while to get shore power

With that sort of PSOC use you should probably be doing a short equalization of about 2-3 hours every 3-4 weeks.

[phantomracer]

Originally Posted by Maine Sail

With that sort of PSOC use you should probably be doing a short equalization of about 2-3 hours every 3-4 weeks.

Thanks

would running the balmar alternator (w/ 614 regulator) help equalize them...or do i really need to get a proper charger and do it at the dock?

[phantomracer]

Originally Posted by Maine Sail

With that sort of PSOC use you should probably be doing a short equalization of about 2-3 hours every 3-4 weeks.

was reading your article on the smart gauge. thinking of installing one at some point. looks great

[a64pilot]

Originally Posted by phantomracer

Thanks

would running the balmar alternator (w/ 614 regulator) help equalize them...or do i really need to get a proper charger and do it at the dock?

Might consider a Honda portable to do the equalization as opposed to being tied to a dock?
I just installed this charger, and am quite impressed with it, it pulls I believe 900W or so, so a little Honda could run it easily.

Marine Battery Charger - Sterling Power ProCharge Ultra- Power Factor Corrected (PFC) PCU - 60amp

[phantomracer]

Originally Posted by a64pilot

Might consider a Honda portable to do the equalization as opposed to being tied to a dock?
I just installed this charger, and am quite impressed with it, it pulls I believe 900W or so, so a little Honda could run it easily.

Marine Battery Charger - Sterling Power ProCharge Ultra- Power Factor Corrected (PFC) PCU - 60amp

not crazy about lugging a generator to and from the boat each time i want to charge the battery...and having gasoline on board makes me nervous as well.. plus dropping another $1500 .. just easier/cheaper to take it into the dock time to time

[sailorboy1]

Originally Posted by phantomracer

.. plus dropping another $1500 .. just easier/cheaper to take it into the dock time to time

First time I needed to really charge my batteries out on my mooring I went and got a 800W unit from Harbor Freight for $80. It was noisy but I only used it in the afternoon for a few hours and it was less than going to the dock. Afterward I had a nice little portable unit that came in handy at home.

[svlamorocha]

Originally Posted by phantomracer

If I were solar only, wouldn't this still be the case..get charged during the day (providing it was sunny)..and i hit it hard at night with a lot of use (computer, fridge, radio, lights, etc) bringing the voltage down to a low level?

This would be correct is correct if you are talking about up to 300W (say 120Ah per day into batteries) or so of solar in the Caribbean. Numbers will differ elsewhere. After all, it is all about how many Ah the charging source brings in per day. You will need to top up with engine to bring batteries up to 100% every onice in a while. There is one difference though. With solar it is easy to get a cheap controller that will manage the charge properly (say the new Victron MPPTs that sell for $100 and can manage 2x100 in series)

If you are talking about a bigger solar setup (say 400W and up in the Caribbean) then you can spend a lot of juice and still have batteries at 100% every evening (which means the DOD between sunset and sunrise will be healthy) with just solar.

MaineSail has pointed out the weakness of the charging controller algorithm of those fuel cells. I have other concerns given the small capacity of the charger. If I was in your position I would do the work to confirm that the thing can run a proper 3-stage algorithm despite the mismatch between the charger and the rest of the system.

I presume you would start by setting the absorption voltage to a reasonable value (14.2V is too low for your batteries, say 14.8V to keep things simple) and setting the absorption time of two hours (instead of the silly "immediate cutoff when you reach absorption"). Then try and see if the thing copes with keeping the voltage at the battery (not anyplace else) at 14.8V for two hours. This is the easiest and most important test for the system you have.

One hard constraint is that with a full charging capacity of 5A at 14.XV, it is very likely that when loads hit 4A or so (and there is only 1A going going into a 300Ah or so bank) battery voltage is going to drop enough to reset the algorithm. Hopefully I am worrying about nothing, but this is theusual problem when trying to charge a large bank like yours with a small charger.

If you get the two hours without a problem then you will need to find, based on your daily load patterns, how many hours of absorption are required in order to take the batteries to 100% (which can be determined by current accepted by batteries at absorption voltage, say rated battery capacity divided by 50 hours, aka 2%.) . This will depend on your daily load and charging patterns. This step is inevitable given that your charge controller does not have a shunt or means to set absorption time based on measured bulk time.

[Roy M]

I guess it's time to revive my experience with Pulse Tech desulfators (http://www.pulsetech.net/Content/Our...echnology.aspx). It always brings out a raucous cry from a few stalwarts, but the truth is, it works, despite the naysayers. They recently sent me a copy of the study performed by Oakland University and Ohio State University, confirming the testing. I'll be happy to share it if it's not too disturbing to certain persuasions.

[Maine Sail]

Originally Posted by svlamorocha

I presume you would start by setting the absorption voltage to a reasonable value (14.2V is too low for your batteries, say 14.8V to keep things simple) and setting the absorption time of two hours (instead of the silly "immediate cutoff when you reach absorption"). Then try and see if the thing copes with keeping the voltage at the battery (not anyplace else) at 14.8V for two hours. This is the easiest and most important test for the system you have.

The problem is that the Efoy will turn off once the target voltage is attained, where a decent solar controller does not. The Efoy does not reach target voltage then limit the voltage to that point and hold it there it simply gets to target voltage and shuts off entirely until the voltage falls to 12.3V. Wind generators are similar in their limitations in regards to their ON/OFF shunt/brake type regulation.

If you attain target absorption voltage with a PWM or MPPT controller you will actually get an absorption cycle, where the absorption voltage held steady, for 1, 2, 4 etc. hours. This is what helps reconvert that lead sulfate you have formed via cycling.

Bouncing ON and OFF of a peak target voltage is really a pretty unhealthy method of charging and tends to result in the need for more frequent equalization's or a higher set point on the alt regulator, when the alt is in use.

Even if you push the OFF voltage to 14.6V - 14.8V this is not going to result in a full battery but it will get slightly more full than it does at 14.2V... Changing the ON/OFF points from 12.3V and 14.2V to 13.0V and 14.6V - 14.8V would certainly be an improvement. The Efoy also needs a good sense of the battery voltage, accurately, and the charge wiring needs to drop almost no voltage, unless it has a sense circuit.

[phantomracer]

Originally Posted by Maine Sail

The problem is that the Efoy will turn off once the target voltage is attained, where a decent solar controller does not. The Efoy does not reach target voltage then limit the voltage to that point and hold it there it simply gets to target voltage and shuts off entirely until the voltage falls to 12.3V. Wind generators are similar in their limitations in regards to their ON/OFF shunt/brake type regulation.

If you attain target absorption voltage with a PWM or MPPT controller you will actually get an absorption cycle, where the absorption voltage held steady, for 1, 2, 4 etc. hours. This is what helps reconvert that lead sulfate you have formed via cycling.

Bouncing ON and OFF of a peak target voltage is really a pretty unhealthy method of charging and tends to result in the need for more frequent equalization's or a higher set point on the alt regulator, when the alt is in use.

Even if you push the OFF voltage to 14.6V - 14.8V this is not going to result in a full battery but it will get slightly more full than it does at 14.2V... Changing the ON/OFF points from 12.3V and 14.2V to 13.0V and 14.6V - 14.8V would certainly be an improvement. The Efoy also needs a good sense of the battery voltage, accurately, and the charge wiring needs to drop almost no voltage, unless it has a sense circuit.

I would guess that is their balance between charging a battery and not blowing through all the methanol quickly. I am sure they could do it.. but at an unreasonable cost, no doubt.

would augmenting the system with a small panel be a good compromise..I just can't fit a big array (more dont want to)

never really thought of the unit starting and stopping the way it does.. assumed it kept the batteries topped off.. guess it doesn't .

but it is likely i have sulfation as it is, from what I have read..and that needs to be addressed, as well as a better plan for battery management

[Maine Sail]

Originally Posted by phantomracer

I would guess that is their balance between charging a battery and not blowing through all the methanol quickly. I am sure they could do it.. but at an unreasonable cost, no doubt.

would augmenting the system with a small panel be a good compromise..I just can't fit a big array (more dont want to)

never really thought of the unit starting and stopping the way it does.. assumed it kept the batteries topped off.. guess it doesn't .

but it is likely i have sulfation as it is, from what I have read..and that needs to be addressed, as well as a better plan for battery management

Supplementing with solar would certainly be a help but with a small array the batteries will need a break from "loads" about once every two weeks to allow a FULL CHARGE for a few days. On a boat everything is a compromise.

From your described use Firefly Carbon Foam AGM's would probably suit you better as they can go much longer periods between full charges and still reconvert the lead sulfate.

[phantomracer]

Originally Posted by Maine Sail

Supplementing with solar would certainly be a help but with a small array the batteries will need a break from "loads" about once every two weeks to allow a FULL CHARGE for a few days. On a boat everything is a compromise.

From your described use Firefly Carbon Foam AGM's would probably suit you better as they can go much longer periods between full charges and still reconvert the lead sulfate.

Thanks...

As I mentioned, I am using this charger and wanted to ensure it was up to the task for my battery setup... Is it good enough to top it off..

in the off season, is it advisable to leave this charger plugged in around the clock?

Or is there a better portable charger I should consider

[Maine Sail]

Originally Posted by phantomracer

Thanks...

As I mentioned, I am using this charger and wanted to ensure it was up to the task for my battery setup... Is it good enough to top it off..

in the off season, is it advisable to leave this charger plugged in around the clock?

Or is there a better portable charger I should consider

It will be fine for short periods & equalizing I would not personally use it as a maintenance charger..