A way To Save Charging Time

[Kenomac]

What makes you think that? The purpose of this thread is to understand charging more completely and get everything working properly.

[mitiempo]

Originally Posted by Kenomac

What makes you think that? The purpose of this thread is to understand charging more completely and get everything working properly.

True, that is the purpose of the thread.

But in my opinion you are not likely to do a complete capacity test. It means turning all loads and charging off after the batteries are fully charged and then running a 23 amp load until the batteries hit 21 volts. Then charging to full as soon as possible.

Few electricians would do this.

[Kenomac]

Originally Posted by mitiempo

True, that is the purpose of the thread.

But in my opinion you are not likely to do a complete capacity test. It means turning all loads and charging off after the batteries are fully charged and then running a 23 amp load until the batteries hit 21 volts. Then charging to full as soon as possible.

Few electricians would do this.

But I'm not an electrician. Please offer up some instruction on the easiest way to complete this task after I equalize my battery bank.

When was the last time you conducted this sort of test on your bank?

[mitiempo]

Originally Posted by Kenomac

But I'm not an electrician. Please offer up some instruction on the easiest way to complete this task after I equalize my battery bank.

When was the last time you conducted this sort of test on your bank?

I haven't tested my battery bank, nor any others.

Apply a load that is 1/20th the size your battery bank was when new. Monitor the battery voltage and time how many hours it takes to reach 21 volts. If 20 hours they are as new. If 18 hours they are at 90% of new capacity.

[StuM]

Originally Posted by mitiempo

I haven't tested my battery bank, nor any others.

Apply a load that is 1/20th the size your battery bank was when new. Monitor the battery voltage and time how many hours it takes to reach 21 volts. If 20 hours they are as new. If 18 hours they are at 90% of new capacity.

Ken, in the case of your 450AH 24V system, that would be about a 540 Watt load which should draw about 22.5Amps. (450Ah x 24V = 10,800Wh. 10800/20 = 540. )

NOte: It will draw slightly less Amps initially when the batteries are fully charged (higher Volts) and slightly more when getting to a low voltage/SOC.

[Kenomac]

Sounds like a ceramic heater will do the job.

[barnakiel]

Yes. Initial bank 450Ah.

Over time you reduce this number in the meter memory. I deduct 5% of original bank capacity each year.

b.

[Kenomac]

Some good news. I was away from the boat for 28 hours, and during that time the Ah reading came up to 390Ah and still charging.

I'm getting there.

[Stu Jackson]

Originally Posted by Kenomac

What makes you think that? The purpose of this thread is to understand charging more completely and get everything working properly.

The Ample Power Primer http://www.amplepower.com/primer/primer.pdf

If the link to the primer doesn't work, just go to the Ample website and find it.

[mitiempo]

Originally Posted by Kenomac

Sounds like a ceramic heater will do the job.

22.5 amps DC @24 volts. I doubt a heater would do this.

[a64pilot]

Originally Posted by Kenomac

Some good news. I was away from the boat for 28 hours, and during that time the Ah reading came up to 390Ah and still charging.

I'm getting there.

Bump the thing up to absorption voltage, or its likely a week from now it is still increasing, that is not too much of an exaggeration, very little charging is going on in float, its not supposed to, if there is, your float voltage is too high.

Nobody was disrespecting you on the capacity test, just to do it "right" requires equipment that no cruiser is likely to have and to purchase said equipment is not money well spent, yes you can jury rig something, like a ceramic heater for instance and it may can tell you if your bank is dead or not, but unlikely its going to be able to tell you if you have 420 AH or 390 AH, for that you need the equipment, and time.
To even begin a good cap check you need to cycle the bank at least once, and most importantly be darn sure it is really fully charged, not close, but full.

[a64pilot]

Originally Posted by mitiempo

22.5 amps DC @24 volts. I doubt a heater would do this.

Many ways to do it, for aircraft I use a landing light and an amp meter, not scientific, but tells if there is enough battery to operate the radios and nav gear in the clouds until you can land

[a64pilot]

This is a load bank I built for flight testing an aircraft.
It has eight 600W aircraft landing lights and is a 171 amp load at 28V,

[Kenomac]

Originally Posted by a64pilot

Bump the thing up to absorption voltage, or its likely a week from now it is still increasing, that is not too much of an exaggeration, very little charging is going on in float, its not supposed to, if there is, your float voltage is too high.

Nobody was disrespecting you on the capacity test, just to do it "right" requires equipment that no cruiser is likely to have and to purchase said equipment is not money well spent, yes you can jury rig something, like a ceramic heater for instance and it may can tell you if your bank is dead or not, but unlikely its going to be able to tell you if you have 420 AH or 390 AH, for that you need the equipment, and time.
To even begin a good cap check you need to cycle the bank at least once, and most importantly be darn sure it is really fully charged, not close, but full.

How do I bump it up to absorption voltage on a Mastervolt 24/50 and Mastervolt 24/75?

[a64pilot]

Originally Posted by Kenomac

How do I bump it up to absorption voltage on a Mastervolt 24/50 and Mastervolt 24/75?

I know nothing at all about your charger, however if it is a good one, then you can adjust float and absorption voltages, the way I "bump" my Magnum or Outback 80 is to simply set the float voltage to the same as absorption, that way when it trips to float, voltage stays the same.
It may be that float has to be .1V lower than absorption, if so that is fine.
When fully charged, your amps will stabilize and stop going down. It won't hurt anything to stay in absorption for a few hours, days and weeks it will of course.
It may take longer than you think, I'd guess no more than 5 hours max though.
I am not the expert here, Maine Sail is one though