Battery testing with new load test meter.

[bud37]

Dsolo, have you installed the 1230p charger yet ? Nice banks of batteries you now have, how many amp hours did you end up with for the house bank? Here is why I ask and I know you said you are sticking with it ( 1230p) but now would be the time to correct this.....lets say you have 400ah and use it to 50%, that would leave 200ah to recover.....now depending on all sorts of things like resistance etc if you get 20amps to the batteries your gen would have to be on for 10 hours and I doubt that you will get the batteries back to 100% at that rate, therefore damaging the batteries in the long run.....just some spitballing by me cause I am just doing exactly what you are ( new 6volt bank etc) except I have a 50amp charger, the victron monitor will be a great help if set right ( had one in other boat).......

[dsolo]

bud37, you are correct. The new house bank has 432 ah.I sized the bank based on never going below 50%. I figured lights, Frigidaire, water pump and a couple electronic components. AC would require the generator.

I just read the ProNautic manual and it states sizing with a 1250. I have not installed the 1230, I must rethink this installation. I am pretty sure the AC side is sized to accommodate the 1250. The DC is not. It will require rewiring from 8ga to 6ga. I am sure fuses will need changing also. I am going to the boat tomorrow, had planned to install the batteries and charger. Looks like that won't happen.
Again bud37, thanks for pointing this out.

[dsolo]

km1125, yes the intent was to use the gen batt as back up for the primary starter battery. So how I see things working are the house batteries at #1, switched at dock or anchored. Battery #2 will be starter only, switched to it at departure. The generator battery used isolated to start generator or switched in parallel with primary starter battery. All batteries are connected to the battery selector switch with #2 ga wires. Both negative and positive connections. I believe I should be covered. There is a on/off switch between the gen batt and generator. I wonder if it should be switched to a selector switch for the primary starter battery that would include either or both group 31 batteries?

[Viper]

Charger sizing really depends on the size of your bank, and the type of boating you do. If you don't plan on staying on the hook much such as day trips only and not staying out over night, or boating from port to port, then a lower output charger is fine as you'll spend most of your time on shore power anyway. If you plan on spending weekends on the hook for example, then it's more beneficial to be able to charge as quickly as possible so a higher output unit is desirable. You must keep in mind though that there is a limit to how much amperage to can safely push into a bank.

[km1125]

If you have room and all the wiring is close enough, then you could replace the genset on/off battery switch with something like the Blue Seas Systems Dual Circuit Plus™ Battery Switch and then connect to the engine start battery and engine.

When "on", it would have each start battery dedicated to loads...one to engine the other to genset, but then you can combine both to overcome a starting problem on either side. Switched to 'off' (which you really shouldn't need except for off-season or maintenance) would disco both loads from both batteries.

Is it really 2Ga or 2/0 ga wires? You might have to upsize the wire from genset battery to the switch to make sure it can handle your main engine start current.

[bud37]

Dsolo, I read what you were saying about your setup and it sounds exactly what I have...there are lots of ways I am sure of doing this better but here is how I am going to handle it for now....there is bat#1 on switch ( 4x6v house bank), bat#2 engine start only ( one 1000mca Battery) that is two banks for the charger..will not use the third leg......now I will separate the gen 7.3kw ( one small battery to start 400mca, gen spec is 230min) as it charges its own battery it will be fine.The battery switch is make before break so can be switched with engines on.
I have a clamp meter and will watch the system while on to see how it operates ( don't have the victron yet,ran out of money), but as I have observed doing some trials at home you will probably never see the full rated amps going in the bank because as it fills the amps drop, much of the reason for the pro mariner rec of the 1250 for you....remember you have two or three banks and things running while you are trying to charge.
Check your wire length from where your charger is to the breakers, never know you may be ok......

[Viper]

Source of the post....I am pretty sure the AC side is sized to accommodate the 1250....

If you currently have a 30A unit installed, you'll need to check and make sure the AC wiring is 14 AWG and the breaker is 15A before you install the 50A charger. Most 30A units only required 10A breakers and 16 AWG wire. Carver may have wired for a larger charger by default but you should confirm to be safe.

[dsolo]

Thank you for your input. I will be at the boat tomorrow. I will verify the current specifications.

[km1125]

Source of the post

Source of the post....I am pretty sure the AC side is sized to accommodate the 1250....

If you currently have a 30A unit installed, you'll need to check and make sure the AC wiring is 14 AWG and the breaker is 15A before you install the 50A charger. Most 30A units only required 10A breakers and 16 AWG wire. Carver may have wired for a larger charger by default but you should confirm to be safe.

Do any marine AC systems have less than 14GA wire? I didn't think that was allowed by ABYC. Do any AC systems use less than 15A breakers?

A 50A charger should only draw ~700 watts (~6.5A) , which is well within a 10 or 15A breaker.

[Viper]

Assuming will get you in trouble. Standards change over the years and you can't rely on what previous owners did. Anytime you're retrofitting to a higher output anything that will likely draw a heavier load, you should always check the wiring to ensure it can handle it.

The PronauticP 50A unit (units from 40 to 60 amp) requires a 15A breaker. For most 30A units, a 10A breaker will suffice so it's important to make sure the current wiring and circuit protection is rated to handle the higher load when moving up to a higher output charger. I mean how much trouble are we talking about here? The wire size is stamped on the cable. What may take more work is checking the breaker rating as they're usually labeled on the sides, so if it's in between two other breakers, you won't be able to see the rating unless you pull the breaker out or are lucky enough to have a rating on the toggle.