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DDabs · 16-05-2014, 16:52

So I am in the next phase now of my battery refit. I am going from having two AGM 12V batteries (200ah bank) to six 6V batteries (630ah bank).

The boat came with a Heart Interface/Xantrex battery charger/inverter. My main question is, will this system be adequate to charge the new batteries? I am not as much concerned about the inverter, because I am hardly ever going to use it, but I want to make sure that the charger is compatible.

mariner36bob · 16-05-2014, 17:17

I like the 6v's.
Recently Shed 60 pounds and gained 35Ah.
Want more.
How many Amps is charger?

DDabs · 16-05-2014, 17:41

I think it says 13.5V at 100 amps. Does that sound right?

mariner36bob · 16-05-2014, 18:34

If you thought you'd get sage advice qfrom this guy sorry, I'm learning DC power too....but
I have subscribed to the 20-25% train of thought. I'm seeking a 100A charger for my four 6volts. You'd need 120-150 if you subscribed too.
I don't know the charger you have but do know the boys in our yard scoff at Xantrex as cheap.
To absorb to potential, the trojans want 14.8 volts. That 13.5 won't do it will it. Didn't you just spend a ton of cash?Boats suck money out of me too.

IceDog · 16-05-2014, 19:21

I have a Xantrex MS2000 charger/inverter. In bulk charge mode (when it senses the battery voltage as low, it will charge my large lithium bank at 100 amps. For each hour it does this, it recharges 100AH. The charger switches to absorption mode and then to Float mode when it thinks the battery is full (too early at the moment but it is a new system and I am tweaking it for better performance). You should be able to find an online copy of the operator manual for your Xantrex which will give you more information on the charging voltages for your equipment. Of course this is when on shore power only. I have three solar panels for a total of 250 watts that generally are providing about 11 or 12 amps during the day. Here in Florida and on the hard, I may be averaging 100 or 120 AH of solar charging. The solar bank and controller will bring my lithium bank up to full charge but I am using shore power for some lighting and recharging/running my laptop, phone charger and power tools while working on the boat.
One has to consider all charging sources/scenarios when installing a system. For me it is shore power Xantrex (even now, my solar is doing most of he charging), and when I launch, solar and alternator.
On the hard, I believe the Xantrex will do the job of keeping your batteries charged. I have found that my DC consumption is much higher when the inverter/charger is on in float mode so I now keep my inverter/charger turned off and let the solar do most of the work. In the water, I plan to only turn on the inverter when I need to charge something or use AC.

DDabs · 16-05-2014, 21:02

I have 420W of solar panels that are going to be fed into the battery bank.

I am basically just wondering if the charger I have will work with the batteries while on shore power, or if for some reason it is not sufficient.

**skipmac** · 16-05-2014, 22:26

Quote:

Originally Posted by DDabs

I have 420W of solar panels that are going to be fed into the battery bank.

I am basically just wondering if the charger I have will work with the batteries while on shore power, or if for some reason it is not sufficient.

A 100 amp charger should keep you going just fine while you are plugged in to shore power. I would stick with it as long as it keeps working. I have the same battery setup, 6 X 6 volt batteries for about 630 amp hours. I only have a 70 amp charger and am getting by fine with that.

deckofficer · 16-05-2014, 22:57

Quote:

Originally Posted by skipmac

A 100 amp charger should keep you going just fine while you are plugged in to shore power. I would stick with it as long as it keeps working. I have the same battery setup, 6 X 6 volt batteries for about 630 amp hours. I only have a 70 amp charger and am getting by fine with that.

Your 70 amp charger is just about perfect for a lead acid 630 ah bank. People sometimes forget that the best life out of lead acid batteries is a charge rate of 0.1C, in your case 63 amps. Certain AGM batteries don't mind a 0.5 C, and LiFePO4 can handle at least 1.0C and some even higher.

**skipmac** · 17-05-2014, 07:36

Quote:

Originally Posted by deckofficer

Your 70 amp charger is just about perfect for a lead acid 630 ah bank. People sometimes forget that the best life out of lead acid batteries is a charge rate of 0.1C, in your case 63 amps. Certain AGM batteries don't mind a 0.5 C, and LiFePO4 can handle at least 1.0C and some even higher.

Thanks for posting this. I was trying to remember the optimum rate of charge for FLA batteries.

mariner36bob · 17-05-2014, 15:08

And I've only got a little 30A charles charger on board. Previously serviced a single 100A 4D. For now i'll use it as well. It ain't broke, not gonna fix it.

"the best life out of lead acid batteries is a charge rate of 0.1C"

Was hoping you might explain this please, I don't understand what it means (0.1C) and could not make sense of it searching today. Thank you.

If so, I'm quite happy to hear I may not need a 100A charger as thought. Less cash is always better.

Not trying to hijack your thread man, just working through the same thing on my boat too....

DDabs · 17-05-2014, 16:09

No worries, the more information the better!

deckofficer · 17-05-2014, 16:49

Quote:

Originally Posted by mariner36bob

And I've only got a little 30A charles charger on board. Previously serviced a single 100A 4D. For now i'll use it as well. It ain't broke, not gonna fix it.

"the best life out of lead acid batteries is a charge rate of 0.1C"

Was hoping you might explain this please, I don't understand what it means (0.1C) and could not make sense of it searching today. Thank you.

If so, I'm quite happy to hear I may not need a 100A charger as thought. Less cash is always better.

Not trying to hijack your thread man, just working through the same thing on my boat too....

Batteries have a C rate based on their chemistry. Lead acid (flooded) has a 0.1C preferred charge rate. That means whatever the capacity of the battery in ahr, multiply by 0.1 to determine the acceptable charge rate. If you just have a single 100 ahr battery, a 10 amp charge will give you the best battery life. If you have a large 1000 ahr bank, then you can charge at 100 amps.

Didn't you ever wonder why automotive cheap chargers are 6 amp output? Most car batteries are in the 50 to 70 ahr capacities.

For LiFePO4 batteries, 1.0C is common and they can go to 3.0C. So that same 1000 ahr capacity bank can be charged at 1000 and up to 3000 amps.

mbianka · 17-05-2014, 16:54

Quote:

Originally Posted by mariner36bob

"the best life out of lead acid batteries is a charge rate of 0.1C"

Was hoping you might explain this please, I don't understand what it means (0.1C) and could not make sense of it searching today. Thank you.

What Deck Officer is saying to get the max life out of the battery bank a charge rate of 0.1C is best for AGM.

For example my 210 Amp AGM 48 volt battery bank being charged at a 0.1C rate should have a charger that puts out 21 Amps
.1 x 210(amps)= 21 amp charge rate

So for your battery bank just multiply the total amps of your battery bank by .1 and that should give you the amount of amps your charger should put out for that charge rate. This will give you the best life for your battery. You can pump more amps into the bank at the risk of decreasing it's useful life. It's a balancing act that you have to choose. More amps means less time charging but, also decreased useful battery life. One thing you should always do is charge the bank up ASAP after heavy use. This will also extend useful battery life. Don't let them sit there in a discharged state for too long.