battery charging

[Bacchus]

Am I wrong thinking when I plan on taking a lead from the house battery, put an On/Off switch to the start battery on the generator, for an emergency start of the generator?

What a TF member suggested yrs ago and I did was replace the gen on/off Sw with an 1 - 2 - all - off Sw and connected the #2 position to my house batty bank.
Simpler than adding another Sw as it was the same foot print and bolt hole pattern.
My gen has an alternator and I rely on it to charge gen batty. If I havent used it for a while I connect to the house when connected to shore charger and top off the gen batty charge.

 

[tiltrider1]

What we are talking about here is a back up plan to the back up plan to the back up plan. A generator start battery that is isolated from the rest of the boat and charged by the generator’s alternator should easily last 10 years. Plan A would be to replace that battery every 5 years. Plan B would be to test the generator before each trip. After having preformed Plan A and Plan B the odds of needing a Plan C are next to zero. Having a backup jumper battery or a 1,2,all switch to the house banks are both acceptable as Plan C. Neither solution is perfect but we are talking about a Plan that should never be needed.

 

[FlyWright]

If you's guys would just carry a Honda 2000, you wouldn't need to worry about a generator start source Plan C.

 

[OldDan1943]

What we are talking about here is a back up plan to the back up plan to the back up plan. A generator start battery that is isolated from the rest of the boat and charged by the generator’s alternator should easily last 10 years. Plan A would be to replace that battery every 5 years. Plan B would be to test the generator before each trip. After having preformed Plan A and Plan B the odds of needing a Plan C are next to zero. Having a backup jumper battery or a 1,2,all switch to the house banks are both acceptable as Plan C. Neither solution is perfect but we are talking about a Plan that should never be needed.

tiltrider, I ran my generator one day and it wouldn't start 2 days later. Replaced the battery and all was well. Now maybe you understand my Plan B.

 

[Bacchus]

What we are talking about here is a back up plan to the back up plan to the back up plan. A generator start battery that is isolated from the rest of the boat and charged by the generator’s alternator should easily last 10 years. Plan A would be to replace that battery every 5 years. Plan B would be to test the generator before each trip. After having preformed Plan A and Plan B the odds of needing a Plan C are next to zero. Having a backup jumper battery or a 1,2,all switch to the house banks are both acceptable as Plan C. Neither solution is perfect but we are talking about a Plan that should never be needed.

I like the option to start or charge gen from 2 sources instead of replacing batty twice as often but to each his own.
Many test their engine start battys at start of every trip but still choose to have a back up in place just in case.

 

[tiltrider1]

I am not popoing your plan C. I am saying No one should be criticizing the Plan C’s just because they are not the ultimate solution. As I mentioned earlier I have a plan C and a Plan D but I doubt I ever need either.

 

[TFolwell]

I'm a new Looper, starting in April 2022 with a new Cutwater 30. I have traveled many miles on motorcycles and you can never be over prepared for the adventure. I looked at the book and the 4th addition has all kinds of info that you might need on your Looper trip , I bought the Kindle addition. Thanks for the info.
Tom Folwell
Cutwater 30, Last Pairing

 

[nautic75]

charging system

have been reading all of the suggestions and my head is spinning the general idea is to isolate the batteries from each other. 1 cranking/running battery for each engine. 1 house battery or dc main, 1 inverter battery which is not in a constant use (tv, morning coffee, hairdryer) generator can take care of itself but a crossover solenoid was installed connector to the inverter battery. instead of using the battery isolators considering using the cole hersey isolator solenoid allowing the cranking batteries to be charged directly by the engine and when the cranking battery reaches a preset voltage the solenoid trips and will allow charging of the "companion" battery (the house or inverter battery) the cole hersey solenoid is pt#48525 thoughts?

 

[Bmarler]

have been reading all of the suggestions and my head is spinning the general idea is to isolate the batteries from each other. 1 cranking/running battery for each engine. 1 house battery or dc main, 1 inverter battery which is not in a constant use (tv, morning coffee, hairdryer) generator can take care of itself but a crossover solenoid was installed connector to the inverter battery. instead of using the battery isolators considering using the cole hersey isolator solenoid allowing the cranking batteries to be charged directly by the engine and when the cranking battery reaches a preset voltage the solenoid trips and will allow charging of the "companion" battery (the house or inverter battery) the cole hersey solenoid is pt#48525 thoughts?

i prefer a simpler approach. right now i have two battery banks. one is the engine starting bank. this handles the main and the genset.
then there's a large house bank. this handles all the dc loads including the inverter. charging is handled with an automatic charge relay. your cole hersey solenoid is probably exactly the same.
i have the wiring and switching in place to add a dedicated generator battery, but i don't feel the need for it at this point.

 

[Bacchus]

i prefer a simpler approach. right now i have two battery banks. one is the engine starting bank. this handles the main and the genset.

then there's a large house bank. this handles all the dc loads including the inverter. charging is handled with an automatic charge relay. your cole hersey solenoid is probably exactly the same.

i have the wiring and switching in place to add a dedicated generator battery, but i don't feel the need for it at this point.

Nautic75:
I'm generally in agreement with Bmarler above.
I have a single main eng but wonder why one start bank for twins wouldn't be preferred? I might oversize a single start bank... say 2 GP 31s for both eng as it would provide plenty of power to start #1 easily and you then have #1 alt assisting for #2 start.
I also don't see benefit to separate house & inverter battys... why not combine into one larger bank? Battys should have better life when drawing down less than any one individual and simpler wiring / charging.
I'm a fan of separate gen batty if gen has its own alt charging but I do like a backup on gen as its my last ditch solution if house or start is too weak I can fire up gen and charge either / both. I have mt back up switched (via a 1-2-all vs another Sw) but jumper cables acceptable if thats your choice.

 

[OldDan1943]

The following just my opinion.
A generator generally only requires a small start battery. I added a switch so, in an emergency, I can start the gen from the house batteries.
A start and run battery for each main engine. I have one engine and 1X4D
Put all the house batteries to feed the the inverter.
Because I have but 4X4Ds (one for the main engine start), I opted to put both thrusters on the house. Gotta keep the main engine running and 10.6vts seems to be the magic number to shut down the main engine. Of course, push come to shove, parallel all four 4Ds, head for port and search out a battery supply house.
I am ignoring the 2X130 amp solar panels.

 

[Bmarler]

Nautic75:
I'm generally in agreement with Bmarler above.
I have a single main eng but wonder why one start bank for twins wouldn't be preferred? I might oversize a single start bank... say 2 GP 31s for both eng as it would provide plenty of power to start #1 easily and you then have #1 alt assisting for #2 start.
I also don't see benefit to separate house & inverter battys... why not combine into one larger bank? Battys should have better life when drawing down less than any one individual and simpler wiring / charging.
I'm a fan of separate gen batty if gen has its own alt charging but I do like a backup on gen as its my last ditch solution if house or start is too weak I can fire up gen and charge either / both. I have mt back up switched (via a 1-2-all vs another Sw) but jumper cables acceptable if thats your choice.

i don't have a separate gen battery because my old onan has such a primitive charging circuit. it can burn up a battery pretty easily. the mains bank is plenty big to handle everything. even if i had twin engines i think i'd still use one large bank for starting duty.
if my genset was more modern i'd probably have a dedicated optima for it. really though, starting the mg set from either the mains or house bank is working very well as it doesn't take much to start it.

 

[rgano]

i don't have a separate gen battery because my old onan has such a primitive charging circuit. it can burn up a battery pretty easily. the mains bank is plenty big to handle everything. even if i had twin engines i think i'd still use one large bank for starting duty.
if my genset was more modern i'd probably have a dedicated optima for it. really though, starting the mg set from either the mains or house bank is working very well as it doesn't take much to start it.

My Onan suffered the same issue with the 12-volt charge so I just disconnected it while still keeping its dedicated battery charged via an ACR from the main engines' starting batteries.

 

[OldDan1943]

My generator has its own battery and charged by the generator.
I do have emergency switch, if the gen battery fails, I can start the gen via the house bank.