Lets Talk Chargers

[Midnightsun]

I started thinking about my charger, nothing wrong with it however I am a little concerned about its rated output and not being as smart as I would like. The unit is a Charles 5000 series 60a which is connected to 3 banks.

My issue is although it is rated at 60a, most of this is sitting idle as it really is the house bank that needs all the juice quickly and if I understand this correctly that give me only 20a on the house. On top of this if I read the specs on the link below it only bulk charges for 4 hours as this stage is on a timer which is a rather poor design IMHO but at the time was probably the way it was done. Charles got out of chargers several years back by the way. http://www.charlesindustries.com/marine ... 5B1%5D.pdf

I have been looking at a Pronautic 50a. Seems like they are well liked. The biggest plus is they will transfer up to 100% of their output to a single bank if required which means that very low house bank will get 50a bulk charge as opposed to 20a with the old Charles unit even though it had a higher overall rating. I am quite sure a decade plus of newer tech will make a difference in many aspects of the newer chargers and promote longer battery life with proper charging curves and automatic equalization. http://www.promariner.com/en/news/pronauticp

Here is a link to the model I am considering. http://www.promariner.com/en/63150

Looking for input of others regarding old tech vs new tech chargers, chargers types and is it worth the upgrade. Will set me back around $350 US if I go through with this.

[mjk1040]

Not that I have any expertise in this area, my concern would be can your batteries or bank of batteries take that many amps of charge? What is the optimum battery charging rate so one doesn't damage a battery? Then again if the charger is a "smart" charger you would hope it would only feed a battery what it needed safely! Just a thought!

[Midnightsun]

A battery charger will only feed what the battery can absorb so it really does not matter how big the charger is. It is important that it be of the newer "smart" variety though so that proper regulation is performed automatically. That being said a battery can absorb around 20-40% of its AH rating. In my case I have 435ah house bank which equates to 87-174 amps. Most single standard 12v batteries are around 200AH which comes to 40-80 amps charge acceptance capability. I guess I am trying to say a 50A charger is not damaging to boating applications like ours. Here is a good read on the subject. https://www.westmarine.com/WestAdvisor/ ... ry-Charger

[bud37]

Hans....considering you have wiring for 60 amps now , I would go with at least the 60 and more if the wiring will support it. Rated output is not what your batteries will see unless they are dead.The more charger the better.

Does your Charles get to float ( around 13.2-13.6 ) ? If so it is probably doing its job and not boiling the batteries. Do you have lead acid and if so do you find you are topping up frequently ?

Remember as the charge in the battery comes up the charge rate drops due to the increase in battery voltage. These are the reasons I changed out our old Charles 50,it would not get to float, just installed the new one and hopefully it will work as advertised.

edit.....I just read what you posted, so I guess you can ignore some of this......so what it comes down to is the time to recharge a depleted bank with your generator.

[darrenlife]

I also agree that that the smart chargers have an advantage over what was factory installed. I don’t feel the Charles chargers will put out the amperage required to equalize the batteries and eliminate the sulfation. I use wet acid on my house batteries and after speaking with the manufacturer reps at the boat show was convinced that my stock charger wasn’t doing the trick. I now have a dedicated charger on my house and they seem to be much happier as gennie time has gone down quite a bit

[Midnightsun]

Not sure my wiring from the charger to the batteries is good for 60A as the max output on any bank is only 20a, definitely need to check this out. The AC wiring to the charger is definitely adequate as this is sized for a 60a charger.

Pretty much the generator quick charge like you said that will be improved. Running my generator with the current setup technically nets me 40ah after 2 hours assuming the banks are low enough to take a full output charge. With the Pronautic under the same conditions we are talking 100ah, quite a difference.

Also when the bank is depleted substantially and especially if I double up my house bank as I may do to 870ah. A one night stay charging only bulk for 4 hours as with the Charles timed method only give me 80ah before it tapers off to a float charge (not so smart charger). (wonder if I can reset the timer by cycling the breaker to the charger every 4hrs. ) Point being I cannot top off my bank entirely even after a complete night plugged in. It seems the Charles is rather lacking in this area.

I am old school, wet cell is what I use and will stick with this after costly mistakes and disappointment using AGM.

[bud37]

If you are thinking of going to over 800ah then you definitely need to stay with at least the 60, but probably at that point may need 80, just remember the charge rate is nothing close to linear, it drops substantially, therefore increasing charge times dramatically to get to float.
Do you have a battery monitor like the victron bmv series?....they will show you all that is going on with your banks.

This auto correct is painful

[Midnightsun]

I am getting by with a 20a for only 4hr with a 435ah house bank so I am going to assume 50a continuous bulk will suffice. There are limitations and I am pretty sure 60a is all one can generate on a 15a 110v circuit. Technically the bank should never get below 50% therefor even a 870ah only needs 80% of 435 at bulk charge to be put back in which comes to 348ah or 7hrs plugged into shore power. After bulk the size of the charger no longer comes into play.

I do also have dual 150 watt solar panels that really help keeping the charge up quite often when at anchor. I say quite often because when it is cloudy or the boat is positioned poorly the kinda sorta just look cool not doing much in the charge department.

No battery monitoring system on board, had one 2 boats ago and it really ate into my leisure time as it became an obsession. Much prefer to glance at my digital voltage bank monitor once in the morning when at anchor. If it registers less than 12.4 I start thinking about needing to do something. Now that is what I call simplicity.

[bud37]

Source of the post Technically the bank should never get below 50% therefor even a 870ah only needs 80% of 435 at bulk charge to be put back in which comes to 348ah or 7hrs plugged into shore power. After bulk the size of the charger no longer comes into play.

The math doesn't work that way on the boat, you will be running 12 volt loads at the same time, lights , radio, tv etc that all bite into the charge rate and like I said your rate may start out at 50 amps for sake of discussion but does not stay that way, it drops as the battery gets filled......after a while you may be down to 5-10 amps, and it drops further.....that is the reason for in this case bigger is better within reason IMO. This is just educated spitballing here, my brain cant do the real math anymore. I see nothing good about going to a smaller charger in your case with the boat you have, except the purchase price.....just my opinion...

To add you have a very expensive bank to maintain properly.

[km1125]

Source of the post ..... There are limitations and I am pretty sure 60a is all one can generate on a 15a 110v circuit. .....

For a dedicated 15A, 110v (120v) circuit, you can pull 1500 watts continuously. At DC voltages, that's at least 100A. Figure the inefficiency of the charger, which may be 80-90% and you should be able to get at least an 80 A charger working off a single dedicated 15A circuit.