HELP with twin engine battery bank charging system!!
04-18-2014, 08:28 PM
#31
Charter Member
I'm not aware that Perko makes a switch for 2 motors. I'm guessing his main battery switch is BS's, with the inverter switch Perko
This is the Blue Seas switch I use. It is 2 ON/OFF switches built into 1 housing with the ability to combine both motors/batterys for emergency starting. Does same thing as 3 ON/OFF switches, but does it with just 1 switch. Much cleaner and easier to wire. Actually, uses no extra wires
http://www.bluesea.com/products/5511e/featured
This is the Blue Seas switch I use. It is 2 ON/OFF switches built into 1 housing with the ability to combine both motors/batterys for emergency starting. Does same thing as 3 ON/OFF switches, but does it with just 1 switch. Much cleaner and easier to wire. Actually, uses no extra wires
http://www.bluesea.com/products/5511e/featured
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Last edited by US1 Fountain; 04-18-2014 at 08:34 PM.
04-19-2014, 09:19 PM
#32
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pstorti..I am running both engine through a perko switch that will handle two circuits without combining them. I do have the option to combine is need be. The perko switch has on/off and combine. It has four lugs on the back so both engines are switched through this and are not combined...See the diagram..My house batts are 27 and cranking are 24.
04-20-2014, 08:03 AM
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they are in paralell..they have to be connected on the positive side??? Last time I went out, only had one house battery in the boat, Alts were not tied together in any way...it did find during the day and charged good on the gauge, at night when I was running more loads, lights
even with fridge and inverter turned off, they got hot and dropped down to 12v on the gauge..Thinking about writing up a new diagram and have starboard engine tied in to both cranking batts and have port engine tied into house batts. The alts will not be combined. I must have a way to charge my house bank on the water because I dont always have shore power when we are out until we get back home or overnite at a marina..then I will have shorepower. I still think the Alts are weak...The company said they would knock 20 bucks each off the bigger 110amp alts it I wanted to replace them both. This way...surely I will have enough. Ive been wanting to get an amp clamp to see actually what kind of amps I am pulling...both on the cranking side and house side. Thought about changing over to LED too, at least for running lights and courtesy lights...might be pricey but will be brighter and more efficient..
even with fridge and inverter turned off, they got hot and dropped down to 12v on the gauge..Thinking about writing up a new diagram and have starboard engine tied in to both cranking batts and have port engine tied into house batts. The alts will not be combined. I must have a way to charge my house bank on the water because I dont always have shore power when we are out until we get back home or overnite at a marina..then I will have shorepower. I still think the Alts are weak...The company said they would knock 20 bucks each off the bigger 110amp alts it I wanted to replace them both. This way...surely I will have enough. Ive been wanting to get an amp clamp to see actually what kind of amps I am pulling...both on the cranking side and house side. Thought about changing over to LED too, at least for running lights and courtesy lights...might be pricey but will be brighter and more efficient..
04-20-2014, 09:59 AM
#36
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no that's not what I meant I just wanted to know if isolating the alternators solved the problem and it did not. The way you have it wired is fine I would just add a switch to manually combine the house batteries when the engines are off. Put the second house battery back in. Everything on your diagram is fine except the positive wire connecting the two house batteries.
do not put both starts on one motor and both house on the other.
When you say you have all the lights on at night with the engines running what kind of load are we talking about in watts, and what rpm are the engines turning? if they are just idling the alternators may not be doing much at all. If you are up on plane then they should be putting out close to 1000w each which should be more than enough unless they are also trying to revive dead batteries.
pm me your number if you want some more help.
do not put both starts on one motor and both house on the other.
When you say you have all the lights on at night with the engines running what kind of load are we talking about in watts, and what rpm are the engines turning? if they are just idling the alternators may not be doing much at all. If you are up on plane then they should be putting out close to 1000w each which should be more than enough unless they are also trying to revive dead batteries.
pm me your number if you want some more help.
04-21-2014, 02:11 PM
#37
artselectricinc.com
Platinum Member
Your problem as I understand it:
1. The dash volt meter reads low when lights and other loads are used.
2. Alternators are getting hot under load.
First problem is very common in most boats. Volt meters are sensing voltage from the same wires that are under load when accessories are used. Hence low volt reading. Check voltage with a known good hand held volt meter AT THE BATTERY POST with accessories turned on. If you are getting 13 or better, you are good to go.
Second problem is the more an alternator puts out, the hotter it gets. The lower you drain your batteries, the hotter the alternators are going to get, no way around it. Your house batteries are going to be very, very low if an A/C unit is used for more than a few minutes. I would be very surprised if two 60A alts would keep up with it.
Connecting the engines two alternators together will work just fine, they will not fight each other.
Boats with lots of house batteries that are pulled down a lot are hard on alternators. Running them hot all the time with low batteries will definitely shorten their life over time.
Except for the above problems, your system has been working the way you want. Correct?
1. The dash volt meter reads low when lights and other loads are used.
2. Alternators are getting hot under load.
First problem is very common in most boats. Volt meters are sensing voltage from the same wires that are under load when accessories are used. Hence low volt reading. Check voltage with a known good hand held volt meter AT THE BATTERY POST with accessories turned on. If you are getting 13 or better, you are good to go.
Second problem is the more an alternator puts out, the hotter it gets. The lower you drain your batteries, the hotter the alternators are going to get, no way around it. Your house batteries are going to be very, very low if an A/C unit is used for more than a few minutes. I would be very surprised if two 60A alts would keep up with it.
Connecting the engines two alternators together will work just fine, they will not fight each other.
Boats with lots of house batteries that are pulled down a lot are hard on alternators. Running them hot all the time with low batteries will definitely shorten their life over time.
Except for the above problems, your system has been working the way you want. Correct?
