Controller for engine alternator question

[ted655]

The engine is a 6 cyl. Volvo diesel. I want to replace the stock alternator & get a high output type. I have 2 batt banks. 2 batts for start/glow and 4 large amp hr batts as a inverter bank. All 6 are AGMs.
While underway I want the new alternator to top the starters and then charge the inverter bank as we are underway & using the inverter, drawing from the bank, (at times, almost continually). There are no solar panels in the picture at present. Someday there may be.
Is there a controller that will do this? Which one is best?
Thanks,

 

[Dunaruna]

Re: Controller for engine alternator question

[colour=blue]There is a staggering array of electronic toys to do the job that you want, my own personal preference is a VSR (Voltage Sensing Relay), it will automatically charge the starting batts first, once they are full, it will automatically switch to the house batts. You could also add an AGM maintainer to help keep those batts healthy.

What I like about the VSR is that there are no switches to worry about, and because it is solid state, minimal voltage loss.

I run an 18amp solar panel through a controller into my house batts, the controller is programmable for flooded, AGM or gell. My motor alt feeds a VSR.

What size alt do you currently have? Why do you have 2 starting batts?

 

[ted655]

Re: Controller for engine alternator question

A VSR will handle the full output of a big alternator? Say a A/C unit is running and pulling the full load directly from the alt.
==="What size alt do you currently have? Why do you have 2 starting batts?"====.
Whatever is on a Volvo diesel 6. The boat is up north (Indiana), so I'm guessing they have 2 batts to increase reserve cramking. They are group 24s, not very big. Before we head South to bring her home, I will replace the starters with new. Maybe a single, bigger group ?
I know that when we hit the Old River lock, here in LA. in July, those A/Cs will be running. Atleaste 1 anyway.

 

[Dunaruna]

Re: Controller for engine alternator question

[colour=blue]The VSR is connected between the alternator and battery banks. The inverter is connected between the battery banks and your accessories (A/C etc). The inverter does not draw from your alternator nor does it affect the VSR rating. Marine VSR's are rated up to 300 amp.

You have more than one A/C? What size boat are we talking about and what size motor? You should not need 2 starting batteries although a single group 31 for a diesel is a good idea.

 

[drewpster]

Re: Controller for engine alternator question

Ted, Does the system have problems now? Are you adding AC or does the boat already have it?

 

[ted655]

Re: Controller for engine alternator question

42' Gibson HB. Volvo 6 diesel.
It has a couple lead acids hooked to a small inverter now. It is total electric. Stove, Hot water, refrigerator, 2 A/Cs (fore/ aft RV type roof mounts, around 13 FRA each). It has a good Onan diesel gen. that has to be running EACH time you want to use any of the big stuff. Not that I want to run it all full time off an inverter BUT. I don't see me running down the river AND the generator going also. I want a setup to where we can pop a bag of corn or remove the humidity a bit with 1 of the A/Cs (at least) while underway. The engine is already running way less than flat out, it can make a little juice at the same time.
I searched a bit for VSRs. I found out in a hurry I didn't know enough to find what I need. Can I get a specific type or brand? There are a billion VSRs out there.d. d

 

[Dunaruna]

Re: Controller for engine alternator question

[colour=blue]VSR brand of choice - BEP (water proof, marine rated, yada yada yada).

Ted, I run a 45fter, apart from propane cooking, all the accessories are either 12v or run through an inverter, I do not have a gen unit (hate the noise factor). What you are talking about is definetly doable.

Is the volvo 12 or 24 volt?
Is your refrigeration 12v/24v or 110v (inverter/generator)?

It is possible to run the fridge and A/C's through an inverter, but the stove & hot water will be married to the gen set, they are very high wattage items.

 

[ted655]

Re: Controller for engine alternator question

dThis is a "cream puff". It has spent 90% of it's life tied to a dock (with shore power). All the big stuff is 110 V.
But now we've boight it and it will spend 90% of it's time out in the narshs of Louisiana. we have our fishing boat to come & go. As things wear out, we will replace them with dual or tri power sourcw. Untill then I will make do.
The alternator is 12 V. on the engine
Thanks for the VSR info,

 

[drewpster]

Re: Controller for engine alternator question

I have some experience dealing with high wattage items and inverters. Most of the drivers that drive for the company I turn wrenches for have a fridge, TV, and a microwave. The company limits the inverters to 1000 watts with up to 1200 peak wattage. The trucks have four (4) 750 amp 'dual purpose' batteries. Dual purpose batteries are supposed to serve as start batteries that can handle the discharge cycles of a deep cycle. Some drivers have complained that they cannot run everything at one time without blowing fuses. Keep in mind that these trucks run as much as 24 hrs a day with a 100 amp alternator. We still have trouble keeping he batteries alive. Even with the engine running all the time it takes great effort to keep the batteries charged up.
If I were you I would build a big battery bank and use the genset often. Even then I bet you will be buying batteries every year.

 

[ted655]

Re: Controller for engine alternator question

I hope ypu're wrong. I'm not that smart, but... if you're guys are running 100 amp alternators VS 1,000 watt loads and the're eating those batts like M&Ms, then somethinng just isn't right. Neglect, abuse or cavemanity is afoot somewhere.
The batts U'm looking at have a 400 COMPLETE recharge cycle garuntee. If omly drawm down 60% as recomended then the lifespan is many times that.
1 A/C unit will draw around 1500 watts. While the fan will run continualy, the compressor will not, so the actual continious draw will be less. Add another 500 watts for the fridge and it's still not much for a 100- 150 amp alternator to handle. Certainly not enough to cause any excessive battery drawdowns. I won't run everything at once, that was never my plan.
Actually I'm more worried about over voltage & over chargeing the batts.d

 

[drewpster]

Re: Controller for engine alternator question

Most things look great on paper but turn out differently in the real world. The setup we use is as I described and still battery sulfation is a problem. There are many factors that effect battery efficiency. I do not mean to say that you will not get a perfectly acceptable service life out of your boat batteries. I would simply (and humbly) advise you to be very conservative on how you use power reserves. If you do not like generator noise, plan to buy batteries more often.

 

[ted655]

Re: Controller for engine alternator question

dIt isn't the noise so much. It's that $3.00+ diesel fuel. I realize there's no free lunch, but I hope your wromg aboyt battery life.:'(

 

[Boatist]

Re: Controller for engine alternator question

If your AC is 1500 watts and the Fridge is 500 watts then you need 2000 watts if your inverter is 100 percent efficent and it is not.

2000 Watts at 12 Volts is 166 AMPs. Your going to need more than a 150 amp alternator.