I have a 1993 H33.5 with a couple of deep cycle group 27 batteries that are two years old. I don't seem to be able to make it all weekend anymore with the usual DC requirements, frig, instruments, radios and nav lights. My 1 year old Xantrax 20 amp charger seems to be boiling 1 battery and not bringing either up to full charge. Guess the batteries are shot. What concerns do I need to consider when upgrading to 4 or 8D batteries. I'm normally plug into the dock for charging. Thanks you any imput. Jeff
Ungrading My Batteries
- Thread starter GailForce
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Died after only 2 years?
Something doesn't sound right. Batteries should last longer than 2 years. My group 24s and 27s lasted about 7 years. How far down do you run them? Even though they are deep cycle, that doesn't mean you can run them down real low. If you switch to 4D or 8D, they are not going to last any longer if they are not used correctly. They should never be discharged below 50% of their capacity. Discharges to less than 20% of capacity can be very damaging, and may never recover. Did they ever get cooked dry? The plates should never see air. Exposing the plates to air is fatal. The portion of the plate that drys out in the air is permanetly out of action. Even if you cover them with electrolyte again. If you have always used good practices when on battery, and they still are dying young. then check your altenator and battery charger. I assume you know that when you have a good battery connected along with a bad battery, it does not bring the bad one up to the good. It actually brings the good one down to the bad. Or, you could just have a defective battery. A great book is "Living on 12 volts with Ample Power" by David Smead and Ruth Ishihara. They have 2 books out on 12 volts, and they are my bible.
Something doesn't sound right. Batteries should last longer than 2 years. My group 24s and 27s lasted about 7 years. How far down do you run them? Even though they are deep cycle, that doesn't mean you can run them down real low. If you switch to 4D or 8D, they are not going to last any longer if they are not used correctly. They should never be discharged below 50% of their capacity. Discharges to less than 20% of capacity can be very damaging, and may never recover. Did they ever get cooked dry? The plates should never see air. Exposing the plates to air is fatal. The portion of the plate that drys out in the air is permanetly out of action. Even if you cover them with electrolyte again. If you have always used good practices when on battery, and they still are dying young. then check your altenator and battery charger. I assume you know that when you have a good battery connected along with a bad battery, it does not bring the bad one up to the good. It actually brings the good one down to the bad. Or, you could just have a defective battery. A great book is "Living on 12 volts with Ample Power" by David Smead and Ruth Ishihara. They have 2 books out on 12 volts, and they are my bible.
What brand of batteries?
Jeff: What brand of batteries are you dealing with here? There are many sailors that think that Wal-mart batteries are fine, but they just toss them every other year. I guess they know the quality of their purchase. We got over 10 years of service on a couple of Gel batteries. Several of the years was on an old Pro-Mariner 20. Then I upgraded to a Statpower 40+. We are on about 5 years on our current AGM's. Be sure to check all of your settings on the charger. You may want to contact Xantrex and see if they have any advise for you too. If I was going to purchase new a new battery setup today, I would consider 6v AGM's. I do not like dealing with the battery maintenance especially during the winter months when I am absent from the boat for several weeks at a time.
Jeff: What brand of batteries are you dealing with here? There are many sailors that think that Wal-mart batteries are fine, but they just toss them every other year. I guess they know the quality of their purchase. We got over 10 years of service on a couple of Gel batteries. Several of the years was on an old Pro-Mariner 20. Then I upgraded to a Statpower 40+. We are on about 5 years on our current AGM's. Be sure to check all of your settings on the charger. You may want to contact Xantrex and see if they have any advise for you too. If I was going to purchase new a new battery setup today, I would consider 6v AGM's. I do not like dealing with the battery maintenance especially during the winter months when I am absent from the boat for several weeks at a time.
Discharge Levels
JC has some great thoughts on his post. I'd just like to add that knowing the voltage reading at the terminals will tell you how much it's discharged. At a 12.8 voltage reading it's 10% discharged. At 12.2 it's 50%. And at 11.7 it's 80% discharged (20% of it's capacity left before it's completely dead). And he's right. Going below 20% of the battery's capacity will damage it.
JC has some great thoughts on his post. I'd just like to add that knowing the voltage reading at the terminals will tell you how much it's discharged. At a 12.8 voltage reading it's 10% discharged. At 12.2 it's 50%. And at 11.7 it's 80% discharged (20% of it's capacity left before it's completely dead). And he's right. Going below 20% of the battery's capacity will damage it.
Battery Care
Get yourself a hydrometer at any auto supply. This will tell you the exact state of charge in each and every cell. Also if you check them regularly it will allow you to add water as needed. The best way to long batter life is battery care. I use the Wal Mart Max batteries for house batteries, and they will last almost as long as the AGM batteries, if properly cared for. At a far lower cost. If you don't want the hassle of regularly checking and adding water, then the AGMs are for you.
Get yourself a hydrometer at any auto supply. This will tell you the exact state of charge in each and every cell. Also if you check them regularly it will allow you to add water as needed. The best way to long batter life is battery care. I use the Wal Mart Max batteries for house batteries, and they will last almost as long as the AGM batteries, if properly cared for. At a far lower cost. If you don't want the hassle of regularly checking and adding water, then the AGMs are for you.
Battery Monitor
I recommend you start with a battery monitor so you can use real numbers (Xantrex Link 10 or 20, Victron BMV-501, etc). I would disconnect the battery charger and test the batteries. The Smart Charger you have should do a good job so I suspect the fault is with the batteries and their installation. Continuing to charge a defective battery is a bad idea. Verify condition of battery and if necessary replace them both. Verify ventilation around batteries and connections. Use the monitor to gather real data about your loads and build a battery bank 5 to 6 times that daily load. The battery charger will easily support 225 amp/hr of batteries. Hope this helps! Trevor
I recommend you start with a battery monitor so you can use real numbers (Xantrex Link 10 or 20, Victron BMV-501, etc). I would disconnect the battery charger and test the batteries. The Smart Charger you have should do a good job so I suspect the fault is with the batteries and their installation. Continuing to charge a defective battery is a bad idea. Verify condition of battery and if necessary replace them both. Verify ventilation around batteries and connections. Use the monitor to gather real data about your loads and build a battery bank 5 to 6 times that daily load. The battery charger will easily support 225 amp/hr of batteries. Hope this helps! Trevor
Which Battery Monitor?
Which monitor would you recommend? I'm looking for one that's 1. Easy to read 2. Low priced 3. Easy to install and use 4. Low priced 5. Wall mounted 6. Low priced Ned and Tani Strain s/v Family Therapy 1995 h336 Chicago
Which monitor would you recommend? I'm looking for one that's 1. Easy to read 2. Low priced 3. Easy to install and use 4. Low priced 5. Wall mounted 6. Low priced Ned and Tani Strain s/v Family Therapy 1995 h336 Chicago
Monitors
Hi Ned - Most of the monitors out there are the same: Link 10, E-meter, etc. Victron has one called the BMV-501. These are all one bank monitors, supposing you have your house bank wired into one with a separate start battery. All loads need to be connected through the negative shunt provided with the meter. You set the total amp hour capacity and are then able to track loads, charge, and available amp hours. It's a worthwhile addition to any electrical system. Best, Trevor
Hi Ned - Most of the monitors out there are the same: Link 10, E-meter, etc. Victron has one called the BMV-501. These are all one bank monitors, supposing you have your house bank wired into one with a separate start battery. All loads need to be connected through the negative shunt provided with the meter. You set the total amp hour capacity and are then able to track loads, charge, and available amp hours. It's a worthwhile addition to any electrical system. Best, Trevor
Trevor
Great job you're doing on this forum! I wish you had done this a long time ago. I have no problems now, but have to agree that my Link 10 is very valuable. It's one of my 3 favorite toys. I kinda wish I had a two battery monitor, but I can sort of tell what the 2nd battery is doing by comparing the usage between the two. I was going to combine the two batteries into one bank some day anyway. I think the Offshore store is about a block away from my boat, at Freemont Boat Co. I should drop in sometime when I'm looking for the next big purchase, even though my wife asked me the other day if I was through buying stuff for the boat (Ha).
Great job you're doing on this forum! I wish you had done this a long time ago. I have no problems now, but have to agree that my Link 10 is very valuable. It's one of my 3 favorite toys. I kinda wish I had a two battery monitor, but I can sort of tell what the 2nd battery is doing by comparing the usage between the two. I was going to combine the two batteries into one bank some day anyway. I think the Offshore store is about a block away from my boat, at Freemont Boat Co. I should drop in sometime when I'm looking for the next big purchase, even though my wife asked me the other day if I was through buying stuff for the boat (Ha).
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