Balmar 612 field threshold does not seem to be adjustable.

[New Song]

I'm pretty sure this adjustment is where my problem might lie. I have AGM batteries, and is preset at 14.4 volts. It will field the alternator to get it up to 14.6 and then the drops out a couple seconds until it settles to 14.2. Then it will goose the batteries with 10-20 amps until it sees 14.6, and so on. This does not seem like an efficient way to charge, and could be more than just annoying. In advanced programming, it will not scroll to FBA or FFL. The menu ends at mode 12 ("E1c", or equalization time) and starts back over again. The software revision number is R.3.0. The unit was brand new in the box, but I bought it second hand, so I might have an older unit I am presuming. So I don't know where that will put me with tech assistance from Balmar. Figured I'd check here first, and get all my ducks in a row before I give them a call.

Is this kind of treatment going to be bad for my batteries, and is there a way to remedy this?

[Paul L]

Check this writeup on the 612 and AGMs Charging AGM Batteries With An Alternator On A Cruising Sailboat

[zboss]

Does anyone have a good value for the "Field Threshold - Bulk To Absorption" and the "Field Threshold - Float To Absorption" settings on the Balmar 614 for Trojan 6volt flooded batteries?

I have increased my minimum "force" absorption time and bulk time but my alternator is still dropping into float well before the batteries reach the bulk and absorption voltages of 14.8

[Stu Jackson]

Where have you located the battery sense wire? Back of the alternator or at the house bank?

[Maine Sail]

Originally Posted by zboss

Does anyone have a good value for the "Field Threshold - Bulk To Absorption" and the "Field Threshold - Float To Absorption" settings on the Balmar 614 for Trojan 6volt flooded batteries?

I have increased my minimum "force" absorption time and bulk time but my alternator is still dropping into float well before the batteries reach the bulk and absorption voltages of 14.8

This is most like a "volt sensing" issue and your regulator thinks it has already done 14.8V...

*Your v-sense red wire must go to house bank + terminal

*Your regulator negative black wire must go to the house bank negative.

*Are you sure you properly saved your "advanced settings"...?

The red v-sense wire and black regulator negative are your volt sense circuit. Many folks often forget the regulator black wire is part of the v-sense circuit and Balmar does not do a good job in the manual laying this out.

[jcapo]

Question for Maine Sail. I have a MC-512 that sources field current via the sense connection.

Originally Posted by Maine Sail

*Your v-sense red wire must go to house bank + terminal

I sense at the batteries via 15ft of 6ga.

*Your regulator negative black wire must go to the house bank negative.

I connect to the house bank negative via 15ft of 2/0.

The 512 hunts at about a 2 hz. rate when it is limiting voltage. Hunting peaks at 15+ volts. The average voltage when measured with a Fluke min/max/avg mode is the voltage the 512 is trying to maintain.

Balmar says that's the way its supposed to work. I didn't like putting 15+ volts on my gels so I moved the sense back closer to the alternator. The voltage is now under control but I have to restart the regulator several times to get a decent charge since the regulator does not see the drop through 15ft of 2/0 cable from the regulator to the batteries.

I upped the sense wire from 10ga to 6ga thinking the voltage drop due to field current in the sense wire was the hunting problem but that's not the case.

Maine Sail, do you think moving my regulator negative to the battery negative would solve the hunting? Or is the hunting just the nature of the 512 since newer Balmar regulators have a dedicated sense wire.

[Maine Sail]

Originally Posted by jcapo

Question for Maine Sail. I have a MC-512 that sources field current via the sense connection.



I sense at the batteries via 15ft of 6ga.

And this sense wire carries nothing but the regulator on it??

Originally Posted by jcapo

I connect to the house bank negative via 15ft of 2/0.

And if that 2/0 is also carrying alt current you will most likely still have incorrect sensing.

Originally Posted by jcapo

The 512 hunts at about a 2 hz. rate when it is limiting voltage. Hunting peaks at 15+ volts. The average voltage when measured with a Fluke min/max/avg mode is the voltage the 512 is trying to maintain.

Balmar says that's the way its supposed to work. I didn't like putting 15+ volts on my gels so I moved the sense back closer to the alternator. The voltage is now under control but I have to restart the regulator several times to get a decent charge since the regulator does not see the drop through 15ft of 2/0 cable from the regulator to the batteries.

I upped the sense wire from 10ga to 6ga thinking the voltage drop due to field current in the sense wire was the hunting problem but that's not the case.

Maine Sail, do you think moving my regulator negative to the battery negative would solve the hunting? Or is the hunting just the nature of the 512 since newer Balmar regulators have a dedicated sense wire.

It will certainly help but your 512 should never be set for anywhere close to 15V for GEL batteries. It should be set at 14.1V and 13.8V.

The only way to correctly sense is at the physical battery terminals with wires that carry minimal current (regulator load only).

The field wire is grounded back through the alt so it is taking the 2/0 wires path and the reg neg usually only carries about 1A +/- so 10 or 12GA gets you very accurate depending upon length.....

That said the 512 is getting very long in the tooth and the 614 is a far better regulator and has better voltage control as well as many more custom programing options. For the 512 & GEL you want Program 2 IIRC.......

[jcapo]

Originally Posted by Maine Sail

And this sense wire carries nothing but the regulator on it??

Correct.

And if that 2/0 is also carrying alt current you will most likely still have incorrect sensing.

Yes, the 2/0 is carrying alternator current.

It will certainly help but your 512 should never be set for anywhere close to 15V for GEL batteries. It should be set at 14.1V and 13.8V.

The regulator is configured for 14.1 bulk. The hunting is what drives the voltage up. The average of the hunting voltage is 14.1

The only way to correctly sense is at the physical battery terminals with wires that carry minimal current (regulator load only).

The field wire is grounded back through the alt so it is taking the 2/0 wires path and the reg neg usually only carries about 1A +/- so 10 or 12GA gets you very accurate depending upon length.....

I will rig a temporary negative directly to battery negative and see if that fixes the problem. The more I think about it the more I think it will.

That said the 512 is getting very long in the tooth and the 614 is a far better regulator and has better voltage control as well as many more custom programing options. For the 512 & GEL you want Program 2 IIRC.......

Yeah, its old but there's only so much money available for upgrades vs. stuff that's truly busted.

I am using Program 2.

Thanks for your input.

[zboss]

Originally Posted by Maine Sail

This is most like a "volt sensing" issue and your regulator thinks it has already done 14.8V...

*Your v-sense red wire must go to house bank + terminal

*Your regulator negative black wire must go to the house bank negative.

*Are you sure you properly saved your "advanced settings"...?

The red v-sense wire and black regulator negative are your volt sense circuit. Many folks often forget the regulator black wire is part of the v-sense circuit and Balmar does not do a good job in the manual laying this out.

I double checked the connections... there were two "thicker" red wires emerging from the regulator and going into a cable sheath and emerging out the other side with one going to the alt and the other heading into the battery section. The alt side had a fuse so I took that out and verified I could still get voltage out the one that was connected to the v sense pin, which I did.

The only thicker black (Ground Input) wire goes to the alt which then goes to the battery.

I will double check the programming I did. They are not clear on exactly what you need to do to save the programming except to say that system voltage needed to be above 12.5 volts, which it was.

Mainesail - I found a write up of yours on sailnet about this regulator, so I am going to review what you wrote there before follwing up again.

Thanks for your help.

[jcapo]

I ran a 10ga for the regulator negative across the cabin sole to the battery bank negative. No joy, still hunts. Reduce power by 50% with the "belt manager" and no hunting but reduced charge current as expected. Voltage drop measured at the regulator sense and regulator negative is about 100mv from measuring at the bank. Paralleled 3 10ga it still hunts. Voltage drop about 50mv.

I'm going to investigate the negative path from the alternator to the bank.

Originally Posted by jcapo

Correct.
I will rig a temporary negative directly to battery negative and see if that fixes the problem. The more I think about it the more I think it will.

[cwyckham]

I had severe hunting on my mc614 when the battery sense cable broke. It sounds like you're sure you have the right cables going to the right places and that your connections are all good, but that is the exact behavior (including peaking around 15V that I saw.

[Maine Sail]

Originally Posted by jcapo

I ran a 10ga for the regulator negative across the cabin sole to the battery bank negative. No joy, still hunts. Reduce power by 50% with the "belt manager" and no hunting but reduced charge current as expected. Voltage drop measured at the regulator sense and regulator negative is about 100mv from measuring at the bank. Paralleled 3 10ga it still hunts. Voltage drop about 50mv.

I'm going to investigate the negative path from the alternator to the bank.

Sounds like a bad connection somewhere.. Remember voltage drop is current dependent. If your bank is near full you will see little voltage drop..