Isolator/combiner question that I have not found an answer to in the archives. Will I damage the alternator on my Yanmar 2QM15 if I hook an AC smart charger to my isolator? The goal is to charge both batteries and maintain their independence. My only current charging source on my H33 is the engine alternator which connects to a 70A isolator which then connects to 2 independent batteries. I am trying to find the easiest way to connect a newly purchased smart charger to both batteries for dockside charging and still keep them separate. In hindsight I should've purchased a charger with dual outputs. Any insights?
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Combiner
You can use the WM combiner to do that, and replace the isolator with it...The isolator isn't as efficient as the combiner is... Ed
You can use the WM combiner to do that, and replace the isolator with it...The isolator isn't as efficient as the combiner is... Ed
Second that.
I think the combiner is the way to go also. I have a Heart inverter/charger attached to the house bank(three gels). The combiner monitors their charge state and then opens a path to the starter battery(an AGM). It is easier to trust the combiner if you regularly test the voltages for each.
I think the combiner is the way to go also. I have a Heart inverter/charger attached to the house bank(three gels). The combiner monitors their charge state and then opens a path to the starter battery(an AGM). It is easier to trust the combiner if you regularly test the voltages for each.
Yes, but....
True, the archives and West Marine say the combiner is better, but in the interim (until I raise another $200), will I blow my alternator if I connect my smart charger to the same terminal on the isolator as the alternator? I can not remember where I may have heard this, but my feeling is that if I connect the AC charger to the same input terminal on the isolator (or even on a combiner for that matter) as the alternator is connected, I may run the risk of zapping the alternator. Thanks for your knowledge.
True, the archives and West Marine say the combiner is better, but in the interim (until I raise another $200), will I blow my alternator if I connect my smart charger to the same terminal on the isolator as the alternator? I can not remember where I may have heard this, but my feeling is that if I connect the AC charger to the same input terminal on the isolator (or even on a combiner for that matter) as the alternator is connected, I may run the risk of zapping the alternator. Thanks for your knowledge.
Isolator response may be a problem
I have the same engine 2qm15 on my 1980 33. Initally I tried to use an isolator with my automatic charger. I found that the isolator would not feed back the battery's condition to the charger for it to "determine" whether it should charge or not. Sometimes it would other times not. So changed to a combiner. I believe the cost was around $70. With a combiner you can hook the charger to either battery and let the combiner make the connection to the other battery. As far as hurting your alternator is concerned, it's regulator should protect it. But, here again I put a separate switch between the alternator and the batteries so that the connection can be broken. The starter switch is also on this circuit so that the alternator switch must be turned on to run the engine. The starting and house batteries run on the normal 1,2,both,off switch and circuits. This set up is overkill and is not needed to provide safe charging.
I have the same engine 2qm15 on my 1980 33. Initally I tried to use an isolator with my automatic charger. I found that the isolator would not feed back the battery's condition to the charger for it to "determine" whether it should charge or not. Sometimes it would other times not. So changed to a combiner. I believe the cost was around $70. With a combiner you can hook the charger to either battery and let the combiner make the connection to the other battery. As far as hurting your alternator is concerned, it's regulator should protect it. But, here again I put a separate switch between the alternator and the batteries so that the connection can be broken. The starter switch is also on this circuit so that the alternator switch must be turned on to run the engine. The starting and house batteries run on the normal 1,2,both,off switch and circuits. This set up is overkill and is not needed to provide safe charging.
isolator questions
Marvin, you won't blow your alternator because the combiner always has one bank connected to the alternator. We've got the west combiner on our 356 and it works great, charging the backup battery when the engine is running and separating it from all the loads, an isolator uses diodes to separate the battery banks, but htere is always some leakage current-the batteries aren't truly independent.
Marvin, you won't blow your alternator because the combiner always has one bank connected to the alternator. We've got the west combiner on our 356 and it works great, charging the backup battery when the engine is running and separating it from all the loads, an isolator uses diodes to separate the battery banks, but htere is always some leakage current-the batteries aren't truly independent.
Not to worry.
Your "AC charger" is actually a DC charger, AC in and 12V DC out. If your wiring is from the factory then the alternator does not attach directly to the battery. It goes to the starter and then to your battery switch. In other words when the battery switch is off there is no connection between the alternator and the battery. When I go to my boat the first thing I do is turn the battery switch to #2 so I can turn on lights and tunes. The charger is still connected and now, with the switch on, is also connected to the alternator via the starter. Almost every boat is wired this way and I have never heard of an alternator problem because of it. All that the alternator is "seeing" is a normally charged battery or batteries.
Your "AC charger" is actually a DC charger, AC in and 12V DC out. If your wiring is from the factory then the alternator does not attach directly to the battery. It goes to the starter and then to your battery switch. In other words when the battery switch is off there is no connection between the alternator and the battery. When I go to my boat the first thing I do is turn the battery switch to #2 so I can turn on lights and tunes. The charger is still connected and now, with the switch on, is also connected to the alternator via the starter. Almost every boat is wired this way and I have never heard of an alternator problem because of it. All that the alternator is "seeing" is a normally charged battery or batteries.
Ed s. where do you put all those batteries
I am having trouble gettig to three! as you found out! the 37c has limited space. How warm do your batteries get while charging? just delivered a 42 j boat and the batteries where to hot to hold your hand on and made a lot of heat in the cabin, they were gells or agm not sure.
I am having trouble gettig to three! as you found out! the 37c has limited space. How warm do your batteries get while charging? just delivered a 42 j boat and the batteries where to hot to hold your hand on and made a lot of heat in the cabin, they were gells or agm not sure.
Ed A I have 4 in the bilge under the centerline
table and one start bat in the starboard cockpit locker. Can't get to the keel bolts under the batteries unless I remove them. but hey, centerline and low has its advantages.
table and one start bat in the starboard cockpit locker. Can't get to the keel bolts under the batteries unless I remove them. but hey, centerline and low has its advantages.
Alternator wired direct to isolator
Thanks for the help. Unfortunately I'm still not certain if I've received a reply to my exact concern. My alternator is directly connected to an isolator which then direct connects to the 2 batteries. My question is whether I could potentially burn out my alternator if I were to connect my smart charger to the same post on the isolator as the alternator. I know the smart charger puts out DC. But I thought I heard somewhere that even a steady 14v dc current flow to the alternator could do it harm. From the replies it seems as though the biggest problem with this configuration would be the tendency for the smart charger to be unable to read the voltage of the isolated batteries and thus not be able to "smart charge." Thanks for the insights.
Thanks for the help. Unfortunately I'm still not certain if I've received a reply to my exact concern. My alternator is directly connected to an isolator which then direct connects to the 2 batteries. My question is whether I could potentially burn out my alternator if I were to connect my smart charger to the same post on the isolator as the alternator. I know the smart charger puts out DC. But I thought I heard somewhere that even a steady 14v dc current flow to the alternator could do it harm. From the replies it seems as though the biggest problem with this configuration would be the tendency for the smart charger to be unable to read the voltage of the isolated batteries and thus not be able to "smart charge." Thanks for the insights.
battery questions
Marvin, your smart charger has to be on the battery side of the isolator, so to do what you're trying to accomplish you need a dual charger or you should switch to a combiner-which doesn't create a voltage drop. the 12vdc from the charger should have no effect on your alternator-both are putting out 12-16 vdc into the same point-they're in parallel.
Marvin, your smart charger has to be on the battery side of the isolator, so to do what you're trying to accomplish you need a dual charger or you should switch to a combiner-which doesn't create a voltage drop. the 12vdc from the charger should have no effect on your alternator-both are putting out 12-16 vdc into the same point-they're in parallel.
centerline batteries
Thats what i wanted to know! what type of battery are you using scott, do you get much heat in the cabin from the batteries. down here that could be an issue. And how large are your batteries. Ed
Thats what i wanted to know! what type of battery are you using scott, do you get much heat in the cabin from the batteries. down here that could be an issue. And how large are your batteries. Ed
OK Ed, now you put me on the spot
I don't know a damn thing about my batteries, except you put water in them. They are the size of car batteries and are mounted sideways (athwartships?) in the bilge on some sort of shelf so the terminal post tops are an inch down from the bottom of the cabin sole, and are all in the bilge compartment just aft of the mast. I have a fancy battery monitor with a 50 page manual that has the ability to do all sorts of stuff which I can't figure how to do such as measure amps used over time, amp remaining, percent used and remaining. It tells me how many amps left in the bank, but I can't remember what the amp rating is I just watch the voltage. Anyway, there are temp sensors which say the battaries are usually operating in the mid to high 70s F. Haven't noticed a heat problem. Keep in mind they are in a bilge where local water is 48 to 52 degrees year round and is little affected by air temperative given all the tidal movement. We usually have a 6 to 12 foot tide range. One more thing, the tops of the batteries are red so they must be really "good" I figure. Scott
I don't know a damn thing about my batteries, except you put water in them. They are the size of car batteries and are mounted sideways (athwartships?) in the bilge on some sort of shelf so the terminal post tops are an inch down from the bottom of the cabin sole, and are all in the bilge compartment just aft of the mast. I have a fancy battery monitor with a 50 page manual that has the ability to do all sorts of stuff which I can't figure how to do such as measure amps used over time, amp remaining, percent used and remaining. It tells me how many amps left in the bank, but I can't remember what the amp rating is I just watch the voltage. Anyway, there are temp sensors which say the battaries are usually operating in the mid to high 70s F. Haven't noticed a heat problem. Keep in mind they are in a bilge where local water is 48 to 52 degrees year round and is little affected by air temperative given all the tidal movement. We usually have a 6 to 12 foot tide range. One more thing, the tops of the batteries are red so they must be really "good" I figure. Scott
Wow! my boat has been 45 a couple times!
And the water gets down to a bone chilling 66 or so when only the tourists swim. I guess it points out that regional differences make lots of difference. It is lots easier to charge a cold battery than one that lives at 85 or 90. Wish i had that battery moitor here, and i see why you dont need it much!
And the water gets down to a bone chilling 66 or so when only the tourists swim. I guess it points out that regional differences make lots of difference. It is lots easier to charge a cold battery than one that lives at 85 or 90. Wish i had that battery moitor here, and i see why you dont need it much!
More H37C battery stuff.
Hot batteries!? I don't think my gels get hot. But they are buried and I cannot say I ever went and touched them. Usually my sail and helm covers are on top. I have one AGM starter battery and two house gels on the hull where the original two were located. A third gel can be seen in the pic, under the inverter. There is room for a fourth right beside it. Six years and still holding a charge. And sorry about the mess in the locker, picture taken during spring cleanup.
Hot batteries!? I don't think my gels get hot. But they are buried and I cannot say I ever went and touched them. Usually my sail and helm covers are on top. I have one AGM starter battery and two house gels on the hull where the original two were located. A third gel can be seen in the pic, under the inverter. There is room for a fourth right beside it. Six years and still holding a charge. And sorry about the mess in the locker, picture taken during spring cleanup.
Ed S and others Ed's battery location reminded
me of an issue I have with water not draining from the deck area outside the cockpit when the boat is at the dock. I end up with water pooling on the deck and either not draining over the stern or not draining into the aft scuppers a couple feet forward of the cockpit. Underway the stern sits down and water drains fine. But sitting at the dock all the city grit etc ends up pooled on the aft deck both sides. When I step from the dock to cockpit some water goes over the stern. Even with two people in the cockpit at the dock the water still remain somewhat pooled. I keep the fuel tank full and the water tanks are usually almost empty. Engine is Yanmar 4 cyl, one start battery in cockpit locker and 4 12V batteries in bilge under dinning table. Boat doesn't list at all at dock. Have 60 ft chain in anchor locker and a refer under chart table and all tools and spares are in v-berth large locker. Holding tank is original and OB and dink are not kept on boat. If the either the bow or stern sat lower at dock then the deck water would drain. Anyone else have this same condition? It's not a big deal but I thnk this is contributing to a small leak into the quarter berth.
me of an issue I have with water not draining from the deck area outside the cockpit when the boat is at the dock. I end up with water pooling on the deck and either not draining over the stern or not draining into the aft scuppers a couple feet forward of the cockpit. Underway the stern sits down and water drains fine. But sitting at the dock all the city grit etc ends up pooled on the aft deck both sides. When I step from the dock to cockpit some water goes over the stern. Even with two people in the cockpit at the dock the water still remain somewhat pooled. I keep the fuel tank full and the water tanks are usually almost empty. Engine is Yanmar 4 cyl, one start battery in cockpit locker and 4 12V batteries in bilge under dinning table. Boat doesn't list at all at dock. Have 60 ft chain in anchor locker and a refer under chart table and all tools and spares are in v-berth large locker. Holding tank is original and OB and dink are not kept on boat. If the either the bow or stern sat lower at dock then the deck water would drain. Anyone else have this same condition? It's not a big deal but I thnk this is contributing to a small leak into the quarter berth.
Exactly the same. . .
as you described it Scott. Two things that you can do. One is to add scuppers. But where since the water pools across a long area? If you tie a few feet of line to the toerail and let it hang off the back a few inches the water will wick off the transom. But the rope will still catch the dirt. And you will still have the stains on the transom. I chose to keep the toerail bolts tight and wash it down before most outings.
as you described it Scott. Two things that you can do. One is to add scuppers. But where since the water pools across a long area? If you tie a few feet of line to the toerail and let it hang off the back a few inches the water will wick off the transom. But the rope will still catch the dirt. And you will still have the stains on the transom. I chose to keep the toerail bolts tight and wash it down before most outings.
scott, me too,
Mine gets nasty in the same spot, with no depression in the deck it would be hard to get a drain to get it all if you installed one. I was even thinking of putting a notch in the toe rail! but probably wont do that.
Mine gets nasty in the same spot, with no depression in the deck it would be hard to get a drain to get it all if you installed one. I was even thinking of putting a notch in the toe rail! but probably wont do that.
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