I have two (2) separate batteries on my H320 using a 1-2-Both switch. The starting battery is connected to the #1 switch position, the house battery is connected to the #2 position. Both batteries are connected separately to the altentor and battery charger but the batteries are connected negative to negative terminal - Why? I want to add an additional battery to the house bank in parallel to the current house battery but am not sure exactly how to connect them since it appears the current batteries are already connected. Do I keep the starting battery (#1) and the house bank connected by negative terminals? Should I add an isolator or combiner between the two house batteries? I've reviewed the archives but can't find an "obvious" answer to my question(s). I'm obviously not a battery expert and appreciate the help in advance.
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Be carefull
All the batteries have a common ground that goes to your engine block. Your new battery(neg) would also be connected to that common ground. Be carefull connecting a new house battery. It sounds like you are not familiar with how current works and may want to defer this work to a professional. Remember that electrical fires are one of the most common problems on boats. Tim
All the batteries have a common ground that goes to your engine block. Your new battery(neg) would also be connected to that common ground. Be carefull connecting a new house battery. It sounds like you are not familiar with how current works and may want to defer this work to a professional. Remember that electrical fires are one of the most common problems on boats. Tim
Get a West Marine Catalog
There is a very good description and diagram to do just what you are thinking about.
There is a very good description and diagram to do just what you are thinking about.
Paralleling batteries
Unless you KNOW the battery you intend to parallel with is new, don't connect a new battery to it - the older one will likely draw more current and reduce the capacity of the new battery. Assuming you have 2 equivalent capacity and comparable batteries, simply conenct them in parallel (pos to pos; neg to neg) and you are good to go. Evertything should be grounded to a single common ground. Don
Unless you KNOW the battery you intend to parallel with is new, don't connect a new battery to it - the older one will likely draw more current and reduce the capacity of the new battery. Assuming you have 2 equivalent capacity and comparable batteries, simply conenct them in parallel (pos to pos; neg to neg) and you are good to go. Evertything should be grounded to a single common ground. Don
Batteries
I agree with Don. I just did this and all you need is two cables and a new starting battery. I went with a high cranking amps starting motor and have been very pleased with the results. One thing, make sure you always start the engine with the switch in the all position. If you switch from one to both with the motor running, you will blow the diodes in the alternator. Sean
I agree with Don. I just did this and all you need is two cables and a new starting battery. I went with a high cranking amps starting motor and have been very pleased with the results. One thing, make sure you always start the engine with the switch in the all position. If you switch from one to both with the motor running, you will blow the diodes in the alternator. Sean
Sean, Just don't switch to Off
You can switch from 1, 2, Both without problem. Just don't switch to OFF while running if you don't have a zap stop installed. The battery switches are make before break, therefore never leave you without a battery connected. OFF does disconnect all batteries. Bill
You can switch from 1, 2, Both without problem. Just don't switch to OFF while running if you don't have a zap stop installed. The battery switches are make before break, therefore never leave you without a battery connected. OFF does disconnect all batteries. Bill
thanks Bill
I switch mine from 1 to 2 when the engine is running all the time. and that was my understanding 1,2, or all but never off while the engine is running.
I switch mine from 1 to 2 when the engine is running all the time. and that was my understanding 1,2, or all but never off while the engine is running.
Connection Diagram
To get an answer to your original question: "Both batteries are connected separately to the altentor and battery charger but the batteries are connected negative to negative terminal - Why?" go to = http://www.trojanbattery.com/technology_connection.htm Other good info on the Trojan site. http://www.trojanbattery.com/customercare_batterymaint.html Someone mentioned not hooking a new battery to an old one. They are correct. You may severly cut the life of your new battery!
To get an answer to your original question: "Both batteries are connected separately to the altentor and battery charger but the batteries are connected negative to negative terminal - Why?" go to = http://www.trojanbattery.com/technology_connection.htm Other good info on the Trojan site. http://www.trojanbattery.com/customercare_batterymaint.html Someone mentioned not hooking a new battery to an old one. They are correct. You may severly cut the life of your new battery!
Think I Got It - Just Need To Clarify Common Groun
Thanks for all of the replies. I am adding a new starting battery and using the two existing batteries for the house bank. Both existing batteries are the same type and were purchased new together. Just to clarify, I should have all three batteries connected neg to neg to neg for the common ground and then connect the parallel terminals on the two house batteries to combine? The starting battery will be connected to the #1 switch position and the house bank to #2.
Thanks for all of the replies. I am adding a new starting battery and using the two existing batteries for the house bank. Both existing batteries are the same type and were purchased new together. Just to clarify, I should have all three batteries connected neg to neg to neg for the common ground and then connect the parallel terminals on the two house batteries to combine? The starting battery will be connected to the #1 switch position and the house bank to #2.
New Battery with Old issues... any hard info?
I have a mixed set of batteries (age-wise, not chemistry-wise) in my boat and have no problems. If I had bought five gel batteries all at the same time, I couldn't have made the mortgage payment that month! No disrespect, but I'm thinkin this might be one of those old wives' tales. I was an aircraft electrician in the army and did depot maintenence on batteries, generators and other electrical components. We would not hesitate to place batteries of different ages in parallel. Does anyone have any expert source that I could read that describe problems with mixing battery ages? I just can't think of any, other than a shorted cell -- which could crop up regardless of the batteries' relative ages. Thanks, Paul sv Escape Artist h336
I have a mixed set of batteries (age-wise, not chemistry-wise) in my boat and have no problems. If I had bought five gel batteries all at the same time, I couldn't have made the mortgage payment that month! No disrespect, but I'm thinkin this might be one of those old wives' tales. I was an aircraft electrician in the army and did depot maintenence on batteries, generators and other electrical components. We would not hesitate to place batteries of different ages in parallel. Does anyone have any expert source that I could read that describe problems with mixing battery ages? I just can't think of any, other than a shorted cell -- which could crop up regardless of the batteries' relative ages. Thanks, Paul sv Escape Artist h336
Many sources and technical info on Batteries
of different ages or condition when connected in parrallel. I'll have to research, but the net-net is when charging, its "typicaly" not an issue. But in the discharge state an older battery might have a much higher internal resistance than a new battery (all batteries by nature have some internal rseistance). What happens is that the one with a high internal resistance looks like a "load" to the newer battery and can continually drain that newer battery.
of different ages or condition when connected in parrallel. I'll have to research, but the net-net is when charging, its "typicaly" not an issue. But in the discharge state an older battery might have a much higher internal resistance than a new battery (all batteries by nature have some internal rseistance). What happens is that the one with a high internal resistance looks like a "load" to the newer battery and can continually drain that newer battery.
What happens depends on their voltage
If the batteries are at the same voltage, then they don't discharge into one another. Their internal resistance is not really an issue. If they are near the same voltage, the discharge is minimal, and it's harmless anyway. So what if a more charged battery charges a less charged battery a little bit? Current follows the path of least resistance. If there are actual current loads present (refrigerators, lights, etc) then the batteries will discharge through those loads, not through one another. Again, I'd love to be referred to any authoritative information on this subject. Paul
If the batteries are at the same voltage, then they don't discharge into one another. Their internal resistance is not really an issue. If they are near the same voltage, the discharge is minimal, and it's harmless anyway. So what if a more charged battery charges a less charged battery a little bit? Current follows the path of least resistance. If there are actual current loads present (refrigerators, lights, etc) then the batteries will discharge through those loads, not through one another. Again, I'd love to be referred to any authoritative information on this subject. Paul
Battery Switch
Just last month I spent two days on anchor and completely drained my two battery house system. I started the motor with the switch on for the starting motor and it started right up. Once it was started, I moved the switch to the both position to recharge the house bank. It promply blew out the diodes in the alternator. The technician at the shop told me that the house bank was so low it created a power surge. Anybody have a comment on that? For $75, I'll never do that again. In fact I think I'll stay on the safe side and never move the switch with the engine running. Sean
Just last month I spent two days on anchor and completely drained my two battery house system. I started the motor with the switch on for the starting motor and it started right up. Once it was started, I moved the switch to the both position to recharge the house bank. It promply blew out the diodes in the alternator. The technician at the shop told me that the house bank was so low it created a power surge. Anybody have a comment on that? For $75, I'll never do that again. In fact I think I'll stay on the safe side and never move the switch with the engine running. Sean
Moving 1-2-Both Switch
Sean, Bill and Dan Conceptually, even with a field disconnect switch, you should be able to move the switch (except to off) through the different positions without harming the diode in the alternator. However, switch contacts get old with age, and then they do disconnect, doing damage. We just NEVER move the switch with the engine running. If the boat is wired properly to charge batteries, you never should have to. If you use your start battery to do just that, and wire your alternator to your house bank, with a combiner or an echo charge to the start bank, you should never have to use ALL to start the battery or to charge the house bank. Once the engine is OFF, move the switch to the house bank. It's a pretty simple and easy and doesn't require West Marine's recommended three switches at all. Stu PS Tony, souonds like you understand the wiring correctly now. Good luck.
Sean, Bill and Dan Conceptually, even with a field disconnect switch, you should be able to move the switch (except to off) through the different positions without harming the diode in the alternator. However, switch contacts get old with age, and then they do disconnect, doing damage. We just NEVER move the switch with the engine running. If the boat is wired properly to charge batteries, you never should have to. If you use your start battery to do just that, and wire your alternator to your house bank, with a combiner or an echo charge to the start bank, you should never have to use ALL to start the battery or to charge the house bank. Once the engine is OFF, move the switch to the house bank. It's a pretty simple and easy and doesn't require West Marine's recommended three switches at all. Stu PS Tony, souonds like you understand the wiring correctly now. Good luck.
confused again, Stu???
just when I thought I had it figured out! Stu, I have one switch located near the starting bat, and another switch next to the panel. the switch next to the panel controls the house batts, 1,2,all, off, the switch next to the starting bat also has 1,2,all, off. I believe the switch next to the starting batt only charges the house when switched to 2 and charges all when switched to all. further when the starting batt switch is switched to 2 it charges house batt 1,2 or all as indicated on the house batt switch. of course there is one starting batt and 2 houses batt. suggestions???
just when I thought I had it figured out! Stu, I have one switch located near the starting bat, and another switch next to the panel. the switch next to the panel controls the house batts, 1,2,all, off, the switch next to the starting bat also has 1,2,all, off. I believe the switch next to the starting batt only charges the house when switched to 2 and charges all when switched to all. further when the starting batt switch is switched to 2 it charges house batt 1,2 or all as indicated on the house batt switch. of course there is one starting batt and 2 houses batt. suggestions???
Many ways to skin a cat
Previous advice re. banks in parallel is right-on. Recommendation is to start with two new batteries of same type/brand. Connect across posts + to + and - to common ground. They are treated then as one bank. Switches use depend on how they are wired. Only by tracing the wires can you know how they work. I would have separate on/off (only) switch for starting batt.-the line to the starter only. Connect altenator charge and sense wire to starting batt. not switched. Never have to worry about blown diodes because charge wire is not switched. Also, separate on/off (only) switch for house whether one or two banks. Interconnect starting and house with a battery combiner (W. Marine or yandina.com) This will insure any charging source (whether altenator or shore pwr.) is shared. The Combiner can be wired to a switch so that you can turn it on, off, or automatic. It won't handle a starting load but will allow you to dump charge from house to starting in an emergency. What the above really does is: 1. separate house and starting loads 2. prevents open charge circuit (blown diodes) 3. allows sharing of charge source 4. simplifies operation as both switches are either on or off - clean, clear - one for engine, one for house. Never the twain shall meet. Checkout sailnet.com for Blue Sea Systems Parallel Battery Switch DC Panel BSS8080. This is a switch panel based on the ABYC recommendation. (Sailnet.com best prices on this.) The above follows the ABYC standards which has moved away from the 1/2/Both type switches. The Combiner manages the connection and the flow of charging current (check out yandina.com for lots of details) To protect your investment, checkout the catalinaowners.com new item #15675 - Battery Saver. Put this between your house banks and your house distribution panel and never have to worry about trashing your batteries. This no hastle device will cut the load when your battery gets down to 10V before batteries die. Too much advice, too little time.
Previous advice re. banks in parallel is right-on. Recommendation is to start with two new batteries of same type/brand. Connect across posts + to + and - to common ground. They are treated then as one bank. Switches use depend on how they are wired. Only by tracing the wires can you know how they work. I would have separate on/off (only) switch for starting batt.-the line to the starter only. Connect altenator charge and sense wire to starting batt. not switched. Never have to worry about blown diodes because charge wire is not switched. Also, separate on/off (only) switch for house whether one or two banks. Interconnect starting and house with a battery combiner (W. Marine or yandina.com) This will insure any charging source (whether altenator or shore pwr.) is shared. The Combiner can be wired to a switch so that you can turn it on, off, or automatic. It won't handle a starting load but will allow you to dump charge from house to starting in an emergency. What the above really does is: 1. separate house and starting loads 2. prevents open charge circuit (blown diodes) 3. allows sharing of charge source 4. simplifies operation as both switches are either on or off - clean, clear - one for engine, one for house. Never the twain shall meet. Checkout sailnet.com for Blue Sea Systems Parallel Battery Switch DC Panel BSS8080. This is a switch panel based on the ABYC recommendation. (Sailnet.com best prices on this.) The above follows the ABYC standards which has moved away from the 1/2/Both type switches. The Combiner manages the connection and the flow of charging current (check out yandina.com for lots of details) To protect your investment, checkout the catalinaowners.com new item #15675 - Battery Saver. Put this between your house banks and your house distribution panel and never have to worry about trashing your batteries. This no hastle device will cut the load when your battery gets down to 10V before batteries die. Too much advice, too little time.
Dan (back)
Dan Sounds like the switches aren't all wired 1-2-B. Could well be being used as simple on - off switches. Check the wiring on the back, maybe not all three posts are connected. Stu
Dan Sounds like the switches aren't all wired 1-2-B. Could well be being used as simple on - off switches. Check the wiring on the back, maybe not all three posts are connected. Stu
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