Picking New Battery Charger

[Strait Shooter]

Originally Posted by wingless

To indicate power status and to toggle output power.

On my boat my inverter provides power to buried electronics. I can use the remote inverter panel to cycle power, if a reset is required to remove confusion.

Got it!

[mitiempo]

Originally Posted by wingless

As stated and linked, the AGM number is a recommended minimum and the flooded cell is the recommended number.

The AGM batteries will handle more current w/o issues, they like more current.

The flooded cell batteries do not tolerate excess current. The short term effect is boiling away the electrolyte. The long term effect is battery damage. The smart charger runs through several voltage versus time profiles and can dump too much current into a flooded-cell battery, if not properly sized. The first smart charging stage, the ~4 hour bulk charging, is an over-voltage charge to rapidly restore missing charge to the battery. It is possible to decrease the over-voltage level, decreasing the current being dumped into the battery, by selecting a different battery topology on the charge, changing from flooded-cell to AGM or GELL, as stated in this charger FAQ.

A flooded battery starts to gas after 14.4 volts. As long as the voltage is not higher than 14.4 there are no issues with excessive current. At a given voltage - 14.4 - the current is determined by the battery. The only way a flooded battery will accept more current from a larger charger, assuming both chargers are 25% of C or greater, is to increase the voltage.

In addition, the page you linked to recommends a charger of 50% of C. In many installations this isn't even possible. There are many house battery banks on both sail and power boats over 400 AH and I have installed quite a few banks over 900 AH.

As far as the starting battery my preference is a battery to battery charger such as the Xantrex Echo Charge, Balmar Duo Charge or similar. I run all charge sources to the house bank only as it is the bank most in need.

[svHannabel]

I'll be replacing my OEM Charles Industries unit (hums incessantly!) with a Sterling ProCharge Ultra, per MaineSail's recommendation. I'm hoping this is a fairly easy plug-n-play swap out since electrical systems are not my forte.

[FlyingCloud1937]

The other thing I don't see in the picture, is the chassis ground for both the charger and the inverter.

Make sure those get installed.

Lloyd

Originally Posted by Strait Shooter

Thanks for the compliment, it looks even better now, but I have no current photo on here.

Good catch on the inverter orientation, you're absolutely correct. The install, though further along than the picture, still has a few things going on. The repositioning of the inverter is one of many.

A quick side note, that inverter came to me at a great price and is why I even have a xantrex onboard at all. It's technically "not for marine use".

Oh, and I don't agree with the charger/inverter combos. One could be considered a mission critical piece of equipment. The other, not so much. I was taught that you don't mix those.

[Canibul]

Originally Posted by skipmac

Based on this information I hereby withdraw my offer to pay shipping to FL for the IOTA.

dang.
Well, how about a Jack Russell Terrier? Can get him into the smallest Fed Ex box, for a while. Could ship him on an overnight?

Or an entire lifestyle? House overlooking the ocean, two boats, a new car, workshop with tools, etc? Heck I'll throw in the blog, too.

[skipmac]

Originally Posted by Canibul

dang.
Well, how about a Jack Russell Terrier? Can get him into the smallest Fed Ex box, for a while. Could ship him on an overnight?

Or an entire lifestyle? House overlooking the ocean, two boats, a new car, workshop with tools, etc? Heck I'll throw in the blog, too.

Forget the Jack Russell. Had one and he tried to bite me. Never was a fan after that.

Might take the lifestyle. Retirement is looming. Will trade you a small house in north FL with a project boat parked in the woods 5 miles out of town.

[Rusty123]

Originally Posted by mitiempo

A flooded battery starts to gas after 14.4 volts. As long as the voltage is not higher than 14.4 there are no issues with excessive current. At a given voltage - 14.4 - the current is determined by the battery. The only way a flooded battery will accept more current from a larger charger, assuming both chargers are 25% of C or greater, is to increase the voltage.

In addition, the page you linked to recommends a charger of 50% of C. In many installations this isn't even possible. There are many house battery banks on both sail and power boats over 400 AH and I have installed quite a few banks over 900 AH.

As far as the starting battery my preference is a battery to battery charger such as the Xantrex Echo Charge, Balmar Duo Charge or similar. I run all charge sources to the house bank only as it is the bank most in need.

I think you may have misread their sizing recommendation. They recommend 50% of C, divided by 8 (hours). So for a 900 AH bank, the recommended charger would be 56 amps. 25 amps for a 400 AH bank.

The Charles literature states that their "bulk" phase is at 14.5 volts, and runs for four hours (no more, no less), so a charger significantly larger than their recommendation might indeed cause excessive gassing. I guess that's why they suggest switching to the gel profile if you're losing too much electrolyte, but that seems like a hokey solution to me.

[Maine Sail]

Originally Posted by smac999

the newer xantrax ones are junk and fail a lot.

I've put a bunch of these in lately. haven't seen a 2 bank charger. just leave 3rd one open

ProNauticP Series | ProMariner

with 400+ ah of batteries you probably want a 60+ amp charger.

The designer of that charger, Charles Sterling, suggests a jumper to the unused outputs from the others as a "best practice". ProMariner says in their manual this is not necessary but they are the identical charger with the exception of the graphics.... Having spoken with Charlie about this personally, his feeling is that it is the best practice to evenly load all the outputs.

From the Sterling PCU Manual:
"Any outputs that are not being used should be linked across to one that is. This is not a requirement on these new models but is good practices as it spread the loads."

[hellosailor]

I'd be surprised if none of the "shore" chargers use modern "stageless" charging the way MPPT controllers do. Apparently a number of the MPPT chargers reaed battery voltage, and then apply "battery+n" volts, where n is an increment or percent based on their own charging schemes.

So if your battery is at 12.1, the charger may apply maximum amperage at 12.3 volts, not 14.4, and every so many seconds it stops, reads battery voltage again, and adjusts the charging voltage again. Once the battery reaches the programmed set point, it may go into a float mode or do other things, but the point is that these chargers never use dumb "stages" or "steps", they always follow battery voltage.

As this was explained to me, this minimizes bubbling in the electrolyte, which minimizes internal resistance, which makes the charging faster, keeps the battery cooler, and increases efficiency and battery life. With cheap microprocessors and memory these days, there's no reason this can't be done in a $100 charger, much less anything bigger and more expensive.

Anyone know of any chargers that are using this logic yet?

[hellosailor]

Maine-
I would expect that when you evenly load all the output circuits, you also spread the heat load across all of them, so they age evenly, and they each run cooler when the load is shared across them all. Cooler means radically increased component life, so sharing the load could be a very good thing for the longevity of the charger.

[Strait Shooter]

Originally Posted by FlyingCloud1937

The other thing I don't see in the picture, is the chassis ground for both the charger and the inverter.

Make sure those get installed.

Lloyd

Yep, already complete.
I'll take some fresh pics tomorrow and post them.

[Rusty123]

Originally Posted by hellosailor

Maine- I would expect that when you evenly load all the output circuits, you also spread the heat load across all of them, so they age evenly, and they each run cooler when the load is shared across them all. Cooler means radically increased component life, so sharing the load could be a very good thing for the longevity of the charger.

It's important to note that this won't necessarily work with all chargers. I used to have a Guest (Marinco) charger with multiple outputs, but the manual specifically prohibited connecting them together. So what I really had was three little chargers in the same enclosure. Not so useful, since I didn't have three banks.

[mitiempo]

Originally Posted by Rusty123

I think you may have misread their sizing recommendation. They recommend 50% of C, divided by 8 (hours). So for a 900 AH bank, the recommended charger would be 56 amps. 25 amps for a 400 AH bank.

The Charles literature states that their "bulk" phase is at 14.5 volts, and runs for four hours (no more, no less), so a charger significantly larger than their recommendation might indeed cause excessive gassing. I guess that's why they suggest switching to the gel profile if you're losing too much electrolyte, but that seems like a hokey solution to me.

Interesting. One recommendation for charger size is between 10 and 23% of the bank's size in AH at the 20 hour rate. That would be about 60 to 70 amps output for the op's 440 AH batteries assuming they are combined into one bank. Much more realistic to me - as well as the Trojan Battery Company where this information comes from.

For a 900 AH bank it adds up to 130 to 140 amps.

[Rusty123]

Originally Posted by mitiempo

Interesting. One recommendation for charger size is between 10 and 23% of the bank's size in AH at the 20 hour rate. That would be about 60 to 70 amps output for the op's 440 AH batteries assuming they are combined into one bank. Much more realistic to me - as well as the Trojan Battery Company where this information comes from. For a 900 AH bank it adds up to 130 to 140 amps.

My takeaway is that the appropriate size of charger might vary, based on how "smart" the specific charger is. If the charger applies 14.5 volts of four hours, no matter the initial state of charge (like the Charles), then charger capacity enters into the charge profile equation, and it should be sized accordingly.

But if the charger applies voltage in a more sophisticated fashion, accommodating different initial states of charge, then sizing can be based on economics and available charge time (overnight?), a more sound approach, and probably what the Trojan recommendation is based on.

[mitiempo]

Originally Posted by Rusty123

My takeaway is that the appropriate size of charger might vary, based on how "smart" the specific charger is. If the charger applies 14.5 volts of four hours, no matter the initial state of charge (like the Charles), then charger capacity enters into the charge profile equation, and it should be sized accordingly.

But if the charger applies voltage in a more sophisticated fashion, accommodating different initial states of charge, then sizing can be based on economics and available charge time (overnight?), a more sound approach, and probably what the Trojan recommendation is based on.

The Charles, while probably well built, does seem out of date in design.

ps I would always take the recommendations of the battery manufacturer over those of the charger manufacturer.