What is the best way to configure a inverter/charger

[Joint Custody]

For those of you that have inverter/charger system or those of you that are very knowledgeable on laying out a inverter system I would value your input.

I will be installing a new inverter/charger this week.

This will replace the one I have now.Reason for replacing is the charger side of the inverter bit the dust.
I will be putting back in the same:
Xantrex Freedom SW 3012 inverter/charger
Output power 3000w

The current configuration is Inverter/charger + four lifeline AGM GPL-4CT 6 volt 220 amp hours each batteries.
No secondary battery charger and the batteries are not tied to the alternators but are tied to the gen through the inverter/ charger.

This configuration powers the 110 side of the house. Refrigerator , microwave, ice maker and all 110 outlets nothing more than that.

The bank of inverter/charger batteries are only tied to the inverter and gen and not the alternators.

I am told by Xantrex that the charger side of the inverter will not come on until it reads 10.5 volts from the batteries.

My question is with the engines we have would tying the inverter bank of batteries to the alternators overload the alternators as they already are putting a charge to the 12 volt house/starting batteries.
We have cummings 6CTA8 with stock OEM alternators.

The only reason I would want to do this is to keep the inverter bank " topped off" while underway.

Would this be overkill or something worth doing?

We are also looking at adding a 330w solar panel to the hard top.This would go to the inverter bank.

Thanks for the help
Jim

 

[Hoplite808]

If you already have an inverter wired in to the system then don't change anything. It should be already set up correctly.

Inverters will drain the 12 volt batteries fairly quickly unless there is something like an alternator restoring the charge while the inverter runs. A solar panel is more of a trickle charger. If the system doesn't already have you can add a battery isolator that will allow the alternator to charge multiple batteries at the same time while not allowing them to be drawn from together.

The idea for having an inverter onboard is so that you can have AC power available for certain systems while underway and then start your generator at anchor for AC power when not plugged in to shore power.

 

[ranger58sb]

This configuration powers the 110 side of the house. Refrigerator , microwave, ice maker and all 110 outlets nothing more than that.

We had ours installed that way.

I am told by Xantrex that the charger side of the inverter will not come on until it reads 10.5 volts from the batteries.

This sounds off. That voltage is "dead." Suggest you re-check that, and/or compare against products from other makers.

-Chris

 

[ranger58sb]

The idea for having an inverter onboard is so that you can have AC power available for certain systems while underway and then start your generator at anchor for AC power when not plugged in to shore power.

Mmmm... That's ONE idea. Another is to size the battery bank so you'd only have to run the genset at anchor occasionally to recharge batteries, heat water, and cook in an electric galley. Of course that depends on aircon needs, too...

-Chris

 

[ttmott]

I agree the cutoff voltage is way too low; don't ever let it take your batteries down that far. Install a shunt and battery monitor so you always know the state of charge on those batteries.
Regarding using the alternators - I think it is a great idea and easily done. Install a couple of DC to DC chargers, one for each alternator. They are inexpensive and will control the charge to the batteries.
https://www.victronenergy.com/dc-dc-converters/orion-tr-smart-non-isolated

 

[dtfeld]

I have a very similar system except Magnum Energy inverter and recently converted to LiFePO4 batteries. I like Tom's idea of the DC-DC chargers to top up the inverter batteries. Pretty slick idea, and can be set up to only charge while engines running This would work for both chemistries.

I am not as familiar with the Xantrex inverters, but in the Magnum Energy inverters with the ME-ARC remote, there is an option to force a bulk or float charge cycle. Because lithium prefers to be stored at a lower charge, I usually run the batteries down while out, and leave them between 50%-90% SoC for storage. When I'm ready to go again, I can force a charge cycle to start and charge up using the generator. However, this is a manual process, and due to the large battery capacity, can can take a couple hours to recharge. Additionally, I can not run all the AC circuits simultaneously as there are too many high current things on that main breaker (or I have to limit the charge current and I'm still working that out).

That would be the one downside to this setup - they are limited to about 300-400 watts. With your battery bank, it would take several hours of run time to go from 50%-> 100%, so you would have to consider how long you are running the main engines every day to get a decent top up charge. You can parallel these to increase the charge capacity, but in my boat, space for these types of things in limited.

 

[Joint Custody]

All four 6volt are wired together and that is the big issue. We spend four to ten nights off shore power and with the batteries get down to the 11.5 cut off it is taking way to long bringing them back to life with the gen.

Our usual underway time is one to two hours one way that is why I am thinking wiring them to the alternators. If we do that we would put in DC to DC chargers.

We do have a control panel that shows us all settings and the cut off it 11.5.

 

[Joint Custody]

Mmmm... That's ONE idea. Another is to size the battery bank so you'd only have to run the genset at anchor occasionally to recharge batteries, heat water, and cook in an electric galley. Of course that depends on aircon needs, too...

-Chris

This is what we are looking to do.

 

[Brett H]

@Joint Custody I have the similar Xantrex 3024 Inverter Charger. Last winter I added Victron ARGOFET Battery Isolators for each engine. This allows the alternators of both engines to also charge the inverter batteries. I'm not an expert but have been happy with the results. I need a shunt as well, its on the list.

@ttmott Would the DC-DC charger continue to pull from the starting batteries, even after the engines are shut down? Or perhaps there is an internal setting that only charges when receiving higher voltage from the alternator.

Edit: I have no idea which is the better solution.

 

[dtfeld]

@Joint Custody I have the similar Xantrex 3024 Inverter Charger. Last winter I added Victron ARGOFET Battery Isolators for each engine. This allows the alternators of both engines to also charge the inverter batteries. I'm not an expert but have been happy with the results. I need a shunt as well, its on the list.

@ttmott Would the DC-DC charger continue to pull from the starting batteries, even after the engines are shut down? Or perhaps there is an internal setting that only charges when receiving higher voltage from the alternator.

Edit: I have no idea which is the better solution.

The Victron DC-DC battery chargers have an engine shut down detection capability that prevent this when engines are off. I think you can hardwire a switch to turn them off.

They have a phone based app, might even be able to shut them off via the app?

 

[dtfeld]

@Joint Custody

Jim: I've been looking at better ways to charge my battery bank (it get to be an issue with bigger battery banks for inverters for sure).

I just posted up an idea I've been kicking around in my head, but looking to add a high output alternator to my Westerbeke 7.6 BTD generator (http://clubsearay.com/index.php?thr...ut-alternator-to-a-westerbeke-7-6-btd.110535/). Same thing can be applied to the main engine alternators and you can do a dual alternator set up on the 2 main engines to do a quicker charge. But as always, they are not cheap.

I like @Brett H 's idea as well, question is will it give you enough charge capacity given your run time.

 

[Joint Custody]

Does anyone know the amp output of the stock OEM alternators?

 

[dtfeld]

You probably have 50-100 amp alternators, but the next issue your going to run into is the stock alternators are not set up or capable of charging a large house/inverter bank without seriously decreasing their life span or outright killing them pretty quickly. They are there to do a quick replenish of the energy required to start the engines.

Interesting read if considering doing this, and there are a lot of similar articles if you start googling around.

https://stevedmarineconsulting.com/...ry-bank-size-and-charge-capability/?print=pdf

Here another one talking about a Wakespeed dual alternator setup, with additional capabilities or charging LiFePO4 in case you do that in the future (its getting pretty cost competative if replacement batteries ever needed)>

https://seabits.com/wakespeed-ws-500-regulator-review/

 

[ttmott]

The DC to DC charger provides the capability to set up the charge profile which isolators do not plus as @dtfeld alluded they can be configured to only provide output when the engine is running. It seems they do everything you were asking.
So the real benefit they will charge what the bank needs regardless of any other battery bank is doing.

 

[Joint Custody]

The DC to DC charger provides the capability to set up the charge profile which isolators do not plus as @dtfeld alluded they can be configured to only provide output when the engine is running. It seems they do everything you were asking.
So the real benefit they will charge what the bank needs regardless of any other battery bank is doing.

Yes that is what I have been told.

 

[Joint Custody]

You probably have 50-100 amp alternators, but the next issue your going to run into is the stock alternators are not set up or capable of charging a large house/inverter bank without seriously decreasing their life span or outright killing them pretty quickly. They are there to do a quick replenish of the energy required to start the engines.

Interesting read if considering doing this, and there are a lot of similar articles if you start googling around.

https://stevedmarineconsulting.com/...ry-bank-size-and-charge-capability/?print=pdf

Here another one talking about a Wakespeed dual alternator setup, with additional capabilities or charging LiFePO4 in case you do that in the future (its getting pretty cost competative if replacement batteries ever needed)>

https://seabits.com/wakespeed-ws-500-regulator-review/

Good read.

 

[ranger58sb]

All four 6volt are wired together and that is the big issue. We spend four to ten nights off shore power and with the batteries get down to the 11.5 cut off it is taking way to long bringing them back to life with the gen.

Our usual underway time is one to two hours one way that is why I am thinking wiring them to the alternators. If we do that we would put in DC to DC chargers.

We do have a control panel that shows us all settings and the cut off it 11.5.

11.5V is WAY low. You might check your battery info to see what voltage is approx. 50% depth of discharge -- I'd guess somewhere near 12.2V -- since most battery makers recommend not routinely going below that for longest service life.

-Chris

 

[Joint Custody]

11.5V is WAY low. You might check your battery info to see what voltage is approx. 50% depth of discharge -- I'd guess somewhere near 12.2V -- since most battery makers recommend not routinely going below that for longest service life.

-Chris

I would agree. That was what the inverter book suggested. With the new one I am setting it at 12V cut off.

 

[Joint Custody]

This will be how I will wire the new one. Instead of the isolator that will be a DC to DC charger.
We won’t have the automatic Gen Start.