Generator Charging system


D

dstroyed

Member
Does anyone know, does the generator itself have a built in charging system for its battery? I have the external Guest 6am charger. When it dies my gen runs until the battery is dead. I would think that it has its own charging system like some of our small machines at work that have Kohler engines in them. When those quit charging it is usually the voltage regulator which my gen has mounted on the starboard side above the impeller.

Anyone have a preference of 6 amp chargers that may last longer than my Guest. Third one in 5 years that went out.
 
88 Formula 29PC said:
Your genset should charge it's own battery
Click to expand...

In a round about way, right? Genset energizes main AC busses - main AC busses energize battery charger - battery charger then charges all batteries....including the genset starting battery. No direct conduit to the genset battery from the genset itself.
 
My genset has it's own charging system while running. Yours should too.
MY large charger does not charge the generator battery, therefore there is a small guest charger while on shore power to handle it.
 
To answer the original question, yes, your generator has a 12 volt charging system for the starting battery. Your boat also should have a small guest 6 amp charger for the generator battery. Since your generator uses a flooded battery, Formula installs a 120 volt charger for that battery. As GSET stated, your main 3 bank battery charger does not charge the generator starting battery.
 
GSENT said:
My genset has it's own charging system while running. Yours should too.
MY large charger does not charge the generator battery, therefore there is a small guest charger while on shore power to handle it.
Click to expand...

Interesting. If mine is set up in such a way, I'm unaware of it. I was told mine works in the way I described above.
 
Group27 said:
To answer the original question, yes, your generator has a 12 volt charging system for the starting battery. Your boat also should have a small guest 6 amp charger for the generator battery. Since your generator uses a flooded battery, Formula installs a 120 volt charger for that battery. As GSET stated, your main 3 bank battery charger does not charge the generator starting battery.
Click to expand...

Mine is the same as described here.
 
Group27 said:
To answer the original question, yes, your generator has a 12 volt charging system for the starting battery. Your boat also should have a small guest 6 amp charger for the generator battery. Since your generator uses a flooded battery, Formula installs a 120 volt charger for that battery. As GSET stated, your main 3 bank battery charger does not charge the generator starting battery.
Click to expand...

I appreciate all the quick responses! Yes this is how i suspected mine is set up. You are confirming i also have an issue with my generator 12 volt system. I am not 100% sure that i don't have an AGM battery for my gen. I purchased it at West Marine two years ago.

Does anyone know why Formula does the extra 6 amp charger? I can't really see an advantage. Some of my doc/boat buddies seem to think their boat has one charger and their gen pulls from the house or other main battery. Why not do 3 house batteries and one main charger if they really felt the extra battery was needed? Then tie the gen to the house batteries.
 
Strange, I have no additional charger...yet it stay charged ??? So confused ....maybe they did something different on the boats above 34 ??
 
There is an advantage to having a separate starting battery for the generator. If you accidentally leave your house and starting engine batteries in parallel mode and you run them down, you can still start your generator, flip on your main charger and recharge your engine starting batteries. If your generator pulls from the house or other starting battery you can be left without the ability to start your generator.
 
My 350SS also does not have a separate charger for genset battery. It stays charged by the big charger but I'm not sure if the generator itself charges it at all. I think it first goes to the 110 bus and comes back via charger to the battery.
 
You can check the charging circuit on the generator by running the generator, shutting off the battery charger and measuring the voltage across the generator battery terminals. If it's less than 13 volts, either you don't have a charging system or it is not working. If it's more that 13 volts (usually around 14 volts), you have one and it's working correctly.
 
Interesting topic, as I recall my genset has an alternator that charges it's cranking battery. This cranking AGM battery is also connected along with the 4 AGM house batteries to the vessel charging circuit. All batteries are charged with only one 60 amp charger (unless I am simply not noticing the guest charger, there is only one battery charger AC breaker however)
It looks like the genset battery will only crank the genset (can not share cranking amps with house batteries). Each house battery (consisting of 2 AGM large batteries on each side) crank their respective engine (port or starboard) and can be connected in parallel with each other if needed. Each engine has an alternator that charges it's sides house batteries while running.
There is only one DC bus supplying power to the DC panel which must pull from both battery sets (port and starboard) I bet there is a diode in each sides DC feeder to the DC bus to keep each side from transferring power back and forth through the bus/ panel

Formula may have had a separate charger for the genset in the past to accommodate a different type genest cranking battery than the house batteries (gel cel?) before AGM batteries became available for both house and small cranking batteries???
 
Prior to 2007, Formula used a separate Charger for the Generator Battery with the 60 Amp Charles Charger used for the Starboard Engine Battery, 2-Port Battery's (wired in series which serve as the House/Port Engine Battery and the forward Bow Thruster Battery if the boat is fit with a Bow Thruster.

Post 2007, they use the 60 Amp Charles Charger for all 5 battery's - with the 5th Battery being the Bow Thruster Battery located under the forward mattress.

Discovered this during last years post Hurricane Sandy repairs when the New Kohler 7KW Generator (more sophisticated electrical system) remote down below would not work. Seems that the small Generator Battery Charger was putting out some type of electrical "signal" that conflicted with the Generator circuitry. After many, many hours of trouble shooting we disconnected the small Generator Battery Charger and all was well after which I connected the Generator Battery to 1 of the 2 open lugs in the 60 Amp Charles Charger. All is good.....
 
I was looking further into this today and it is a very complicated system. There are two engine start circuit relays that you have to energize to start the engines, my guess these relays isolate each engines start and charging circuits from the batteries while not in use. There is also a battery charger relay on the port side I noticed. Turns out my starboard batteries had 13.7V but my port batteries had 13.2V when I checked them with a meter. Wonder if the charger relay modulates charging current for some reason? I plan to get the wiring diagrams out to figure it out before I have to do it out on the high seas.
 
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