AGM batteries

[Mike Thorpe]

I just put 4 AGM batteries, a Balmar 150A alternator and smart regulator in my CD-36. My question concerns my old single stage battery charger. I know it can't completly top off the AGM batteries but can it harm them i.e. shorten their life?

Thanks,
Mike Thorpe
CD-36 Jopurney's End



mthorpe@capecod.net

[Leo MacDonald CD30K]

I just put 4 AGM batteries, a Balmar 150A alternator and smart regulator in my CD-36. My question concerns my old single stage battery charger. I know it can't completly top off the AGM batteries but can it harm them i.e. shorten their life?

Thanks,
Mike Thorpe
CD-36 Jopurney's End

Hi Mike,

Most of the simplistic singe stage chargers float kind of high and may have rather crude regulation. Check the max voltage allowed on the AGM - should be around 14.1 VDC.
If the battery charger goes above that value its bad news for the Batteries.

BTW - I tried to get an aftermarket Hi Output Alternator with smart regulator - no joy. Anyone know of a alternator / regulator package for a Volvo-Penta MD7A (13 HP.)

Fair Winds,
Leo





macdore@aol.com

[Leo MacDonald CD30K]

I just put 4 AGM batteries, a Balmar 150A alternator and smart regulator in my CD-36. My question concerns my old single stage battery charger. I know it can't completly top off the AGM batteries but can it harm them i.e. shorten their life?

Thanks,
Mike Thorpe
CD-36 Jopurney's End

Hi Mike,

Most of the simplistic singe stage chargers float kind of high and may have rather crude regulation. Check the max voltage allowed on the AGM - should be around 14.1 VDC.
If the battery charger goes above that value its bad news for the Batteries.

BTW - I tried to get an aftermarket Hi Output Alternator with smart regulator - no joy. Anyone know of a alternator / regulator package for a Volvo-Penta MD7A (13 HP.)

Fair Winds,
Leo





macdore@aol.com

[Jim Jones]

Leo,

Take a look at th Ample Power web site. These folks know what they are doing and I have been using their products for 15 years. They have alternators with external 4 step regulators plus the current from the alternator can be reduced ( less load on the engine ) when you need all of your power - heavy wind/seas. This is an real advantage when you don't have that much HP to begin with.

http://www.amplepower.com/

Jim



jjones@intergate.com

[Mark Yashinsky]

Look into Balmar. They produce replacements for all popular alternator styles. www.balmar.net

[Boyd Bundy]

Dear Mike:

Last year I installed 3 AGM batterie in Tern. 2 "deep cycle" and one thin plate starting type. I did this after much research and many conversations with people who sell them. One of the most important management concepts when using these batteries is to have at least a 3 stage "smart" battery charger so that the voltage particularly during the float cycle is within manufacturers specs. If not you will cook them. These batteries have very low internal resistance and the thick plate "deep cycle" or house type will not accept extended charging periods when they have reached full charge. For that reason my starting battery (also an AGM) is a thin plate starting type. The thin plate type will accept charging current for extended periods (like you car battery) without damage. I sometime have been forced to motor for extended periods of no wind and I switch to the starting battery so that the house batteries will not overcharge and possibly be damaged.

If you would like I can dig out the phone numbers of the people I talked with.. very helpful. AGM are great batteries but need to be managed differently.

Boyd Bundy

I just put 4 AGM batteries, a Balmar 150A alternator and smart regulator in my CD-36. My question concerns my old single stage battery charger. I know it can't completly top off the AGM batteries but can it harm them i.e. shorten their life?

Thanks,
Mike Thorpe
CD-36 Jopurney's End

tern30@aol.com

[Larry DeMers]

AGM's need to have the max. voltage level regulated carefully. They do not tolerate over-voltage at all.

Balmar makes both a 70 amp and 80 amp (with 2 internal fans) alternators that would work on the MD7A/B. The only caveat is that you also must get their large diameter pulley for the alternator to work with the large diameter pulley formed by the outside ring of our flywheels. This will give the right pulley ratio for you. Do not go higher than 80 amp alternator however, as the MD7A/B does not have the hp needed. At 80A, you are burning about 3 hp on the alternator alone..that is about 1/3 of your possible hp output. For this reason, I recommend that a cutout switch be installed that cuts your field current. This may be an option with some of the smart regulators. The reasoning is that if you are motoring along, and the alt. is using 3hp, you may indeed need that hp, so the cutout switch could save your feathers.

Cheers and great sailing!

Larry DeMers
s/v DeLaMer
Cape Dory 30

I just put 4 AGM batteries, a Balmar 150A alternator and smart regulator in my CD-36. My question concerns my old single stage battery charger. I know it can't completly top off the AGM batteries but can it harm them i.e. shorten their life?

Thanks,
Mike Thorpe
CD-36 Jopurney's End

Hi Mike,

Most of the simplistic singe stage chargers float kind of high and may have rather crude regulation. Check the max voltage allowed on the AGM - should be around 14.1 VDC.
If the battery charger goes above that value its bad news for the Batteries.

BTW - I tried to get an aftermarket Hi Output Alternator with smart regulator - no joy. Anyone know of a alternator / regulator package for a Volvo-Penta MD7A (13 HP.)

Fair Winds,
Leo

demers@sgi.com

[John R.]

The Balmar Max Charge regulator has a cut out leg for a switch to disconnect the alternator field saving HP at critical times. I've got a 90 amp on a MD7B with no problems. Balmar or Powerline can furnish the pulley calculation formula for anyone interested. In fact I have it somewhere and will look for it if someone needs it. The larger diameter pulleys are also available from any good auto/industrial alternator shop. Best to use a bi-directional pulley exhaust fan also and feed a small 3" blower hose to the rear of the alternator to supply a good cooling air supply into the alternator. Use a small 3" bilge blower.

AGM's need to have the max. voltage level regulated carefully. They do not tolerate over-voltage at all.

Balmar makes both a 70 amp and 80 amp (with 2 internal fans) alternators that would work on the MD7A/B. The only caveat is that you also must get their large diameter pulley for the alternator to work with the large diameter pulley formed by the outside ring of our flywheels. This will give the right pulley ratio for you. Do not go higher than 80 amp alternator however, as the MD7A/B does not have the hp needed. At 80A, you are burning about 3 hp on the alternator alone..that is about 1/3 of your possible hp output. For this reason, I recommend that a cutout switch be installed that cuts your field current. This may be an option with some of the smart regulators. The reasoning is that if you are motoring along, and the alt. is using 3hp, you may indeed need that hp, so the cutout switch could save your feathers.

Cheers and great sailing!

Larry DeMers
s/v DeLaMer
Cape Dory 30

I just put 4 AGM batteries, a Balmar 150A alternator and smart regulator in my CD-36. My question concerns my old single stage battery charger. I know it can't completly top off the AGM batteries but can it harm them i.e. shorten their life?

Thanks,
Mike Thorpe
CD-36 Jopurney's End

Hi Mike,

Most of the simplistic singe stage chargers float kind of high and may have rather crude regulation. Check the max voltage allowed on the AGM - should be around 14.1 VDC.
If the battery charger goes above that value its bad news for the Batteries.

BTW - I tried to get an aftermarket Hi Output Alternator with smart regulator - no joy. Anyone know of a alternator / regulator package for a Volvo-Penta MD7A (13 HP.)

Fair Winds,
Leo