Battery Charge Readings ?

[sailorboy1]

So instead of continuing to highjack another thread or even restarting the one I started about this last year: I have a 460AH house bank consisting of 4 6V wet cell batteries. The batteries are about 1 year old and I monitor them with a Vitron battery monitor that I installed last year at same time as the batteries. The voltage has always seemed lower to me under small loads than I felt was correct (from day 2). The SOC by the meter I don't believe has ever been below 70%. My only charging is via the engine with a 100 amp Balmar alternator and a smart regulator. This weekend I recorded the following data:

time SOC Amp hours amps volts
1910 90.8% -54.4 -0.25 12.12
1955 94.9% -31.1 41.2 13.88
2025 97.9% -13.4 30.5 13.8
2055 100% -.3 24.3 13.87
2110 100% 0 -9.1 12.85
0630 94.9% -31.6 -3.63 12.12
0700 94.9% -31.7 -0.22 12.24
0800 94.9 -31.6 -0.8 12.23
0910 99.8 -1.3 24 13.94
1140 97.5 -12.9 -7.95 12.37
1230 95.4 -23.2 -8.9 12.24
1340 94 -30 -8.5 12.12
2050 98.2 -11.4 -6.1 12.47
2130 97.3 -16.1 -6.9 12.38
0630 93.8 -37.7 -4.3 12.12
0850 96 -25.1 48.3 13.85
0945 99.8 -1.6 16.1 14.03
1045 98.6 -7.9 -6.5 12,52
1220 96.7 -17.7 -6.3 12.34

So ................... ?

[zeehag]

what electrical items were in use as you measured or while you were doing this

[sailorboy1]

Originally Posted by zeehag

what electrical items were in use as you measured or while you were doing this

varied - refrigerator, lights, autopilot, instruments water pump, stereo

this was during 2 days of normal boat use where I ran the engine more than normal to just charge, in fact I motored while sailing a lot this weekend just to charge as the voltage reading have gotten worst

[zeehag]

have you checked your alternator yet with a meter to make sure is putting out ??
those 12.12 numbers are low. th 14s are good--propr charging numbers. but the low ones dont work as charging numbers.

[swisscraft]

I learned this week that you need to check the usage amps and there may need some adjustment (not Victron - Bluesky). Means is you Meter really reading -0.00A when ALL the DC Power is off?

Second, I assume you have a Shunt right? Voltage has some normal up and downs while using power. If you have a Shunt and the state of the Battery (%) goes up and you do not charge, then I would be pretty sure there is an error. Except of course you missed the Windgen spinning on the back of the boat

Correction: Sorry I missed that you charged in the meantime. I would do a check without charging for a period of time to get an impression of the V to % status. My Voltage goes up and down a bit but overall it looks the % number is correct. I noticed Voltage goes up again after some "cooling down" phase - for me this means as example when both danfoss compressors go to standby again....

[noelex 77]

Those numbers suggest the battery monitor is a long way off and your batteries are a lot more discharged than the monitor is indicating.

2055 100% -.3 24.3 13.87
1955 94.9% -31.1 41.2 13.88

The numbers above for example. At 100% charged a battery battery bank should only be accepting 4-5 A, not 24A to keep at 13.8v. At almost 95% charged your batteries should not be accepting 41A ( almost 0.1C) at any voltage let alone 13.9V.

My guess is your battery bank is something like 40% lower than your battery monitor is telling you.

Conect your batteries up to a charger and your "100% charged" batteries will accept a couple of hundred amp hours, indicating that they were really at a much lower state of charge, hence the lower voltage readings.

[FlyingCloud1937]

Originally Posted by Don Lucas

So instead of continuing to highjack another thread or even restarting the one I started about this last year: I have a 460AH house bank consisting of 4 6V wet cell batteries. The batteries are about 1 year old and I monitor them with a Vitron battery monitor that I installed last year at same time as the batteries. The voltage has always seemed lower to me under small loads than I felt was correct (from day 2). The SOC by the meter I don't believe has ever been below 70%. My only charging is via the engine with a 100 amp Balmar alternator and a smart regulator. This weekend I recorded the following data:

time SOC Amp hours amps volts
1910 90.8% -54.4 -0.25 12.12
1955 94.9% -31.1 41.2 13.88
2025 97.9% -13.4 30.5 13.8
2055 100% -.3 24.3 13.87
2110 100% 0 -9.1 12.85
0630 94.9% -31.6 -3.63 12.12
0700 94.9% -31.7 -0.22 12.24
0800 94.9 -31.6 -0.8 12.23
0910 99.8 -1.3 24 13.94
1140 97.5 -12.9 -7.95 12.37
1230 95.4 -23.2 -8.9 12.24
1340 94 -30 -8.5 12.12
2050 98.2 -11.4 -6.1 12.47
2130 97.3 -16.1 -6.9 12.38
0630 93.8 -37.7 -4.3 12.12
0850 96 -25.1 48.3 13.85
0945 99.8 -1.6 16.1 14.03
1045 98.6 -7.9 -6.5 12,52
1220 96.7 -17.7 -6.3 12.34

So ................... ?

Don,

I think you need to get the Vic. BatMon instructions out, and force a default factory re-set. first.

Then set it up for the amphr total of the bat bank, use a 1.3 pukert factor.

Make sure nothing lands on the battery side of the shunt, or the battery.

I'm still converting your #'s to an excel spredsheet, but we will also need to to do a programed discharge/charge before we can ascertain wether it's a bad bat, BatMon, operator error.

Lloyd

[captainKJ]

2025 97.9% -13.4 30.5 13.8

Don,,,is 30.5 the amps that are going INTO the batteries????

at 97.9 that should be way lower. If you are putting that much amperage into the batteries at 97.9 percent I also wonder if your smart regulator might not be working properly... got a volt meter for when it is on??

[sailorboy1]

interesting how answers are different on this thread that on the one about the the gold cart batteries

Nothing wrong with the monitor, it reads the right voltage as I've checked it and I've gone though the settings a couple of times and tightened up the settings etc. And I last syn'd it when the charging amps had gotten down to 2 amps.

The batteries seem to accept the amount of amps expected based on SOC regardless of the battery voltage. If the batteries were really down to 50% charge the voltage suggests I could put in a lot more amps when charging (if I'm not motoring I'll speed the engine up till it doesn't increase amps).

So I'll tell you what I think the problem is - my regulator is not allowing enough voltage for the charging! The charging voltage is only around 13.85. I looked though the regulator manual and I think it is set in the factory default as the voltages seem to match that programing. Since I'm the second owner I bet it has been this way for 11 years. It can be changed to wet cells and ever after than the voltages within the program can be adjusted. I found it also has an equalizer program. I couldn't change it the other day as it requires a little magnet to operate the reed switch.

So I think the charging voltage needs to be increased and the batteries equalized. Now I just need to decide what voltage to use and how long for the equalize charge.

I'm hoping that after a good equalization charge that the voltage holds better during use.

But then ............ what do I know!

[captainKJ]

From another web sight

While batteries need a voltage higher than 13.8 to charge fully, the higher voltage will take its toll on halogen lights, reducing their life considerably. The SAR-V3 includes an input that locks the set-point to 13.8 Volts when desired.

could this be happening????

I know you do not have the SAR-V3 but is it still possible with what you have, a lock somewhere on the charger?? you voltage does not seem to go over 13.8 except once at 14.03 when the state of charge was 99.8,,,that seems to be to high of a voltage for the SOC,

should you not be getting 15.5 volt to charge when you are below 80 percent???



check out this thread

http://www.cruisersforum.com/forums/...ors-53202.html


also have you checked the water in the batteries????,,also checked the voltage of each battery after they are charged,,,one might be low and bad. A battery can turn overnight. one bad battery and it will draw the rest down

[Blue Stocking]

Don,
You may already know this, but your reference to a magnet to adjust the dip switches?
These regs come with a small (usually) white screwdriver, with a small projection out of the handle end,--thats the magnet you need.
Hope this helps.

[sailorboy1]

Originally Posted by Blue Stocking

Don,
You may already know this, but your reference to a magnet to adjust the dip switches?
These regs come with a small (usually) white screwdriver, with a small projection out of the handle end,--thats the magnet you need.
Hope this helps.

I know this now after reading the manual, have tyo go out and find one.

if you have one, how small diameter is the magnet?

[Blue Stocking]

Originally Posted by Don Lucas

I know this now after reading the manual, have tyo go out and find one.

if you have one, how small diameter is the magnet?

--about 1/8", cylinder, 1/4" long, sticks out of the end of the handle.

[Maine Sail]

Originally Posted by Don Lucas

I know this now after reading the manual, have tyo go out and find one.

if you have one, how small diameter is the magnet?

Don,

Couple of questions:

Which Balmar regulator?
Where is the red wire connected?
Is this an MC-6XX or ARS-X?
Can you post a picture of the shunt wiring
Where is the red wire of the Victron connected?
How is the bank connected? Where do the + / - leads leave it?


You may be going into float way to early on that reg, I see this all too often with Balmar's and call it "premature float"..... Also you've adjusted the Ah capacity down on the bank but really have a larger bank this can skew the monitor. Unless you have loads in excess of 20+A then you're battery bank is still taking more current than what the monitor suggests full should be taking.. The re-set to full would be at 2% or less @ 14.4V +/-. Seeing as voltage is pressure your bank will accept a lot less current in the 13's than it does at 14.4V so 2% at 13.XX is not going to represent full very well and the current flowing will not be as representative..

A picture of the battery bank & shunt wiring would really help... The other day you posted a resting voltage of 12.5V but the monitor was reading up in the 90's... That represents about 80% SOC so my guess is that your monitor has not been properly set up or possibly wired so it is not "seeing" everything it should?

Do you have an inverter? Does this load pass through the shunt?

Do you have a windlass? Does this load pass through the shunt?

Do you have a secondary bank? Is this on the load side of the shunt?

[noelex 77]

Originally Posted by Don Lucas

The batteries seem to accept the amount of amps expected based on SOC regardless of the battery voltage. If the batteries were really down to 50% charge the voltage suggests I could put in a lot more amps when charging
!

Have a look at numbers again Don. Batteries will only accept a small amount of charge current once the SOC rises to 90%+.

At 100%( if these figures are current into or out of the battery) yours are still accepting 24.3 A @ 13.87v this is way too high and indicates the batteries are not really at 100%.

2% (9.2A in your case)is commonly accepted figure to drop back to float. So a battery bank your size accepting 9.2A at say 14.4v would indicate your battery bank was reasonably charged somewhere around 96%.