Battery bank backup

[Lwlotowycz]

A lot of electronic on a boat today most important to me is my laptop and cpn and nema accessories. I have threebattery banks aboard. Been thinking of leaving
the 12 volt banks alone and buying a small bank and charger for pc and the boat network. Basically One or two days on the gulf up to a week if I go to the keys. I live right next to the venice inlet south west Fl.
All comments welcome. I am from NJ AND DONT GET OFFENDED BY REJECTION. Ha

[Greg Brannon]

I recommend you take some time to define your daily power requirements and existing storage and recharge capabilities before adding more complication to your (possibly) already over-complicated DC system.

What are the sizes (in 12V Amp-hours), the chemistry/type of your existing banks, and what are the 3 banks being used for? What are your charge sources? Are the charge sources shared by the 3 banks, separate, able to be combined, etc? What control do you have, manual and automatic, of what the 3 banks do and how they are recharged? Do you have an inverter? If so, which one? A simple diagram of your existing system would be helpful.

To get a good answer of how much stored power you need, an understanding of your daily power requirements is required. Create a list of all electrical loads, their power requirements in input voltage and operating amps, and how long you use them each day.

If answering any of the above seems overwhelming or too hard, start with the easy stuff. Answer what you know now or can easily find out, and we'll go from there

Understanding how much power you can put back into storage each day is also important, but that can come next.

Best of luck!

Greg.

[Tin Tin]

What sources and wattage of electric power do you have> Solar, Wind, generator, engine alternator and what type and size of house bank, AGM, Lithium, no of amp hours etc.See also https://www.westmarine.com/west-advi...tery-Bank.html

[Lwlotowycz]

Greg thankyou for all your sound advice. If you email me I will try to address all your questions. Subject of email please put IN HULL 405.
I dug out some old drawings that I will attach to my return email to you.
Thanks again
Leo W Lotowycz
Venice, Florida
One question for you. Where are you located?
Leo

[Lwlotowycz]

Email address. pearsonhull405@gmail.com

[Pete7]

Surely the idea of a forum is someone asks a question and hopefully receives multiple answers with solutions which you are then free to choose or ignore as applicable.

If you post the answers to the questions posed we can all then contribute or learn too.

For me, its not the amount of electric power you store, but how is that power to be replaced which really counts.

Pete

[Greg Brannon]

I support Pete7's notion that the purpose of a forum is to have discussions in the open so that others can contribute, correct, and learn. A contributor's input is based on their own experiences and collected knowledge and that will vary widely across the community. All participants - even those just observing - potentially benefit.

I had more thoughts after my original post that raised more questions I should have asked:

What are you calling '3 banks?' I suspect you mean something different than what readers here would think of as a 'bank.' A typical setup is to have a House Bank and a Start Bank. Those 2 banks are made up of a number of batteries, 1 - X, configured as 12V (usually) or 24V sources, and may have separate, same, or switchable chargers.

Why do you think you need a backup battery (or bank) for your most critical loads? Have you been out and lost those items because your available battery power has gotten so low? Or are you thinking that might happen someday and are planning ahead?

Pete7's point about recharge capability is where we're trying to get to. If reliable, and appropriately-sized recharge capability is not available while underway or at anchor, the only power a boat has is the charge on its batteries when the shore power was last disconnected.

Please take a stab at answering the questions posed so far, focusing on the storage capacity you have and the specifics of that storage, how the storage is configured (what are banks?) and what the banks can be used for, the recharge capability you currently have, and how that recharge capability is used across the 3 banks. If you know or can tell, how old are the batteries?

Greg.
Solomons, MD

[Lwlotowycz]

Greg Hello. I am new to this site less than one week old. I thought I pick out a forum for general questions about the domain of sailing .
With a question about battery back up of a laptop which for me one of the most critical components on my vessel.
The reason for three battery banks is that I have a windless forward on my vessel. Which draws 30 amp. House battery and engine cranking are located 2/3 the distance from the windless. Which is a Long to run supply lines to run on a 35 foot boat. I feel it was a sound decision to add an additional battery.
Relative to battery recharging I have a 75 amp supplier on a new Beta Marine 25.
The alterator on the engine replishes house and en banks. At my slip have a 20amp 120 volt charger connected to all three banks. Also have a solar panel forward with a trickle charger connected to the winless battery to keep it top off. Please note the windless battery is the least use of the three banks.
My decision to power the PC is to install a 1000 watt inverter as it's electrical supply.

[Greg Brannon]

How new is this boat to you? How long have you been using the boat's DC system as it currently exists? I'm assuming you don't have an inverter now. Correct me if that's wrong.

Please provide the number of batteries and their Group numbers/sizes/ratings (whatever you have handy) in both the house and start banks. If the batteries are not 12-volt batteries, please specify what voltage they are.

Do you have manual switches or an automatic battery combiner or isolator to separate the house and start banks? You may have a combiner or isolator and not know it. Unless there's some switching going on, and since both banks are charged by the same alternator, they would essentially be one bank.

What are the input specs, volts and amps, on your laptop's power adapter. You should be able to find that by reading the printing on the laptop's power adapter listed after 'input.'

The windlass 'bank' is a whole other can of worms that can be discussed later, but if it has been working well for you, leave it alone for now. I recommend having a backup plan for when it does not work well.

Greg.

[Pete7]

Originally Posted by Lwlotowycz

My decision to power the PC is to install a 1000 watt inverter as it's electrical supply.

The 1000w inverter is overkill if all you are asking it to power is a laptop. On the laptop mains charging lead will be a oblong block which will tell you the power rating. Think mine is 90w, so I have a 150w inverter to run the laptop. However, to run the kettle we use a 2000w inverter. There is no need to exceed the proposed need because inverters are expensive. However, if you also want to run a printer and large monitor, these also need to be taken into account. Just add up the wattage and add a bit extra.

Pete