Over the last year, I have noticed that the batteries on my CD30 consume electrolyte at a somewhat alarming rate, particularly the deep cycle type. The boat is equipped with a Guest No.2515 15-amp charger which I believe (?) is the ferro-resonant type. The batteries are car-sized units from West Marine - I didn't bother pulling them out of the cases today to read the amp-hour ratings, but I doubt that is relevant to the issue at hand. One is deep cycle and one is a standard unit. I keep the charger on all the time when the boat is in it's slip, and my assumption is that the constant charging is the likely cause of electrolyte consuption. Anyone know for sure? Would changing to a different charger type eliminate this phenomenon and/or be easier on the batteries? Or is this basically harmless as long as I maintain the electrolyte level?
lemans@gte.net
Battery Charging
Moderator: Jim Walsh
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Wolf von Kalben
Re: Battery Charging
I too have the Guest 15 Amp Charger. I maintain the charge season long and find I have to top up the electrolyte level once every 6 weeks or so. The present bank of batteries are 5 years old and test in the green range on all cells.
Wolf von Kalben, CD 27 "SeaChalk II"
wolf.vonkalben@sympatico.ca
Wolf von Kalben, CD 27 "SeaChalk II"
Kevin LeMans wrote: Over the last year, I have noticed that the batteries on my CD30 consume electrolyte at a somewhat alarming rate, particularly the deep cycle type. The boat is equipped with a Guest No.2515 15-amp charger which I believe (?) is the ferro-resonant type. The batteries are car-sized units from West Marine - I didn't bother pulling them out of the cases today to read the amp-hour ratings, but I doubt that is relevant to the issue at hand. One is deep cycle and one is a standard unit. I keep the charger on all the time when the boat is in it's slip, and my assumption is that the constant charging is the likely cause of electrolyte consuption. Anyone know for sure? Would changing to a different charger type eliminate this phenomenon and/or be easier on the batteries? Or is this basically harmless as long as I maintain the electrolyte level?
wolf.vonkalben@sympatico.ca
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Larry DeMers
Re: Battery Charging
Ferro-resonant chargers take a very long time to bring in the final 10-15% of the charge, and in so doing, will cause the electrolyte to gas more than with a "Smart Charger"..considerably more, making level monitoring on a rather frequent basis mandatory.
However, if you leave the charger running while gone during the week, and use the boat on the weekends, the batteries will get their cells filled up quite well..not to the recommended 14.3 volt top end, but probably in the 13.5Volt range. This worked for me for a long time..10 years on one battery, 4 on the other two. That takes care of objection #1.
Next, you check the electrolyte every month, and top off with distilled water as needed..and **Never Ever let the battery cells' plate structure be uncovered by electroyte. This will kill that cell eventually, which kills the battery. That takes care of objection #2.
There is a better way..Smart Chargers combined with Battery Combiners make fast recharging of your bank effective and safe. Each bank gets exactly the charge level it needs, shutting off the charge with a positive relay contact, and not a diode. Gnerally, you will recharge the banks in a matter of hours instead of days.
With my Heart system, I pump 110A into the banks for almost 30 minutes, or until the battery temp starts to climb, when the level is controlled downwards to prevent excessive gassing. This is all automatic ..or manually controlled.
If you plan to move into refrigeration or traveling for longer periods away from the umbilical cord, you will need a way to recharge that bank of house cells quickly and safely..a smart controller for an externally controlled alternator off the engine. The max I can afford power-wise on the MD7B in my CD30 is 3 hp, which is about a 90-100 Amp alternator.
Cheers!
Larry DeMers
s/v DeLaMer
Cape Dory 30 ~~~Frozen solid on Lake Superior..~~~
demers@sgi.com
However, if you leave the charger running while gone during the week, and use the boat on the weekends, the batteries will get their cells filled up quite well..not to the recommended 14.3 volt top end, but probably in the 13.5Volt range. This worked for me for a long time..10 years on one battery, 4 on the other two. That takes care of objection #1.
Next, you check the electrolyte every month, and top off with distilled water as needed..and **Never Ever let the battery cells' plate structure be uncovered by electroyte. This will kill that cell eventually, which kills the battery. That takes care of objection #2.
There is a better way..Smart Chargers combined with Battery Combiners make fast recharging of your bank effective and safe. Each bank gets exactly the charge level it needs, shutting off the charge with a positive relay contact, and not a diode. Gnerally, you will recharge the banks in a matter of hours instead of days.
With my Heart system, I pump 110A into the banks for almost 30 minutes, or until the battery temp starts to climb, when the level is controlled downwards to prevent excessive gassing. This is all automatic ..or manually controlled.
If you plan to move into refrigeration or traveling for longer periods away from the umbilical cord, you will need a way to recharge that bank of house cells quickly and safely..a smart controller for an externally controlled alternator off the engine. The max I can afford power-wise on the MD7B in my CD30 is 3 hp, which is about a 90-100 Amp alternator.
Cheers!
Larry DeMers
s/v DeLaMer
Cape Dory 30 ~~~Frozen solid on Lake Superior..~~~
Kevin LeMans wrote: Over the last year, I have noticed that the batteries on my CD30 consume electrolyte at a somewhat alarming rate, particularly the deep cycle type. The boat is equipped with a Guest No.2515 15-amp charger which I believe (?) is the ferro-resonant type. The batteries are car-sized units from West Marine - I didn't bother pulling them out of the cases today to read the amp-hour ratings, but I doubt that is relevant to the issue at hand. One is deep cycle and one is a standard unit. I keep the charger on all the time when the boat is in it's slip, and my assumption is that the constant charging is the likely cause of electrolyte consuption. Anyone know for sure? Would changing to a different charger type eliminate this phenomenon and/or be easier on the batteries? Or is this basically harmless as long as I maintain the electrolyte level?
demers@sgi.com
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Olli Wendelin
Re: Battery Charging
Kevin,
Why do you charge your batteries constantly? That isn't really good for the battery, provides alternate current leakage/ corrosion paths, and possible electrocution hazards to nearby swimmers. If I don't use my boat, charging the batteries overnight once every 3 or 4 weeks keeps the batteries in shape. If I use the boat every weekend, I end up running the engine a few hours, which keeps the batteries charged.
Olli Wendelin
BLUE MOON
Charleston, SC
wendelin@spawar.navy.mil
Why do you charge your batteries constantly? That isn't really good for the battery, provides alternate current leakage/ corrosion paths, and possible electrocution hazards to nearby swimmers. If I don't use my boat, charging the batteries overnight once every 3 or 4 weeks keeps the batteries in shape. If I use the boat every weekend, I end up running the engine a few hours, which keeps the batteries charged.
Olli Wendelin
BLUE MOON
Charleston, SC
wendelin@spawar.navy.mil
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Larry DeMers
Re: Battery Charging
Olli,
I also run my charger constantly. One reason is safety. If the automatic bilge pump kicks on, I want the charger to keep it running until help arrives..be it me or a curious fellow boater.
Secondly, a ferroresonant charger as Kevin has will not over charge the batteries..it is actually the exact opposite in effect. It charges them so slowly that it probably takes most of the week before the SPG of the cells shows a full charge. It certainly was that way with mine before i changed to a 3 stage charging system (Heart).
AS far as electrolysis or swimmer danger goes, this condition should never be allowed to continue once detected. If you have that kind of isolation problem, then steps must be taken to prevent it. These steps can be to find the leak and repair it, to isolate the AC system of the boat with an isolation transformer onboard, or have the dock power box repaired if it is in need.
Every boat in our marina stays plugged in all summer long, and there are no problems with electrlysis as far as I know (small marina of 40 boats, so I get to see the undersides of them all usually).
This voltage differential can be measured with a milli-voltmeter applied to two immersed metal objects, separated by a bit of distance.
For instance, if you measure from the prop shaft to the head seacock, you should see very little voltage differential..less than 5mv say. The actual number is determined by the type of cell you are forming..what materials and what electrolyte. Contact me if you would like some help tracking down the probelm..
Cheers!
Larry DeMers
s/v DeLaMer
Cape Dory 30
demers@sgi.com
I also run my charger constantly. One reason is safety. If the automatic bilge pump kicks on, I want the charger to keep it running until help arrives..be it me or a curious fellow boater.
Secondly, a ferroresonant charger as Kevin has will not over charge the batteries..it is actually the exact opposite in effect. It charges them so slowly that it probably takes most of the week before the SPG of the cells shows a full charge. It certainly was that way with mine before i changed to a 3 stage charging system (Heart).
AS far as electrolysis or swimmer danger goes, this condition should never be allowed to continue once detected. If you have that kind of isolation problem, then steps must be taken to prevent it. These steps can be to find the leak and repair it, to isolate the AC system of the boat with an isolation transformer onboard, or have the dock power box repaired if it is in need.
Every boat in our marina stays plugged in all summer long, and there are no problems with electrlysis as far as I know (small marina of 40 boats, so I get to see the undersides of them all usually).
This voltage differential can be measured with a milli-voltmeter applied to two immersed metal objects, separated by a bit of distance.
For instance, if you measure from the prop shaft to the head seacock, you should see very little voltage differential..less than 5mv say. The actual number is determined by the type of cell you are forming..what materials and what electrolyte. Contact me if you would like some help tracking down the probelm..
Cheers!
Larry DeMers
s/v DeLaMer
Cape Dory 30
Olli Wendelin wrote: Kevin,
Why do you charge your batteries constantly? That isn't really good for the battery, provides alternate current leakage/ corrosion paths, and possible electrocution hazards to nearby swimmers. If I don't use my boat, charging the batteries overnight once every 3 or 4 weeks keeps the batteries in shape. If I use the boat every weekend, I end up running the engine a few hours, which keeps the batteries charged.
Olli Wendelin
BLUE MOON
Charleston, SC
demers@sgi.com
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Matt Cawthorne
Re: Battery Charging
Kevin,
A key question here is whether or not your charger is working to the correct voltage. You need to measure the charge voltage with a digital multimeter. If it is charging at something like 13.1 volts you should have no problem. If it is charging at above 13.5 it is too much. I used to have a 30 amp newmar charger that charged at 13.1 volts. It would dump in lots of amps if the batteries were really low, but never top off the batteries unless left on all of the time. Since I agree with Ollie and disconnect my boat when I leave the batteries were never topped off. I bought a 10 amp smart charger and have been very pleased with it. It pumps a solid 10 amps into the batteries until they hit 14.4 volts and then drops to 13.+ volts. I only charge the batteries for a couple of hours before I leave the marina to top them off. With that and a smart regulator on my alternator I worry less about the batteries.
My reason for not leaving the boat plugged in is that I worry about safety. Battery chargers are pretty reliable, but I hate the thought of an electrical device going bad on my boat and lighting it on fire or frying a swimmer. My neighbor had his charger boil a battery to the point of it being so hot he could not touch it. How close was he to a fire? I do not know, but as for me I'd prefer not take any chances with the boat or the swimmer.
Matt
mcawthor@bellatlantic.net
A key question here is whether or not your charger is working to the correct voltage. You need to measure the charge voltage with a digital multimeter. If it is charging at something like 13.1 volts you should have no problem. If it is charging at above 13.5 it is too much. I used to have a 30 amp newmar charger that charged at 13.1 volts. It would dump in lots of amps if the batteries were really low, but never top off the batteries unless left on all of the time. Since I agree with Ollie and disconnect my boat when I leave the batteries were never topped off. I bought a 10 amp smart charger and have been very pleased with it. It pumps a solid 10 amps into the batteries until they hit 14.4 volts and then drops to 13.+ volts. I only charge the batteries for a couple of hours before I leave the marina to top them off. With that and a smart regulator on my alternator I worry less about the batteries.
My reason for not leaving the boat plugged in is that I worry about safety. Battery chargers are pretty reliable, but I hate the thought of an electrical device going bad on my boat and lighting it on fire or frying a swimmer. My neighbor had his charger boil a battery to the point of it being so hot he could not touch it. How close was he to a fire? I do not know, but as for me I'd prefer not take any chances with the boat or the swimmer.
Matt
mcawthor@bellatlantic.net