Charging setup for Scimitar

[Qlder1]

Any reason you wouldnt use gas for Hot water and cooking...?

500 watts of solar isnt going int going to provide that much charge, particularly if you get some cloud ..

It also depends how many people you are providing for but Chris's advice is good...a 2-3kw gennie would be a must for extended trips...

It does have a gas stove and bbq, but microwaves and air fryers are so convenient . HWS is heat exchange as well as AC. My thought is that I would be stationary for 2-3 days max, and with only 2 on board, should be able to get away with not running engine unless its cloudy as you say.

540W is fairly small, but on good days it should be enough to at least put back most of what I would use. Theres plenty of space to mount at least 1 more panel but weight is an issue so high up.

Lovey80 thks for the link re EVE batteries, and yeah, the Victron stuff is probably the way to go. Its not so much how well chargers work, its also about reliability and safety.

[Lovey80]

Just saw this link on FB for PowerPaul Australia. If you don’t want to go down the path of building your own system with cells id highly recommend looking at his batteries. He tests and matches everything and even includes an active balance as standard. They aren’t cheap but you could rest easy knowing your battery was built to the highest specs possible.

https://bit.ly/3QP6WOe

[Qlder1]

well, have had the scimitar for a little while now, the thing just floats over what my previous 21ft boat would struggle in, and fuel economy is is probably on par with a largish outboard powered cat, just under 2 litres per nm at 14-15kn. I can see the allure with this type of boat, its very much like a beach house with the ability to just head out whenever you want. I have found that gas stove and bbq pretty much is all thats needed for cooking, but I still want a microwave and airfryer so elect. upgrade is coming...

Of course, like all good things there is a cost. Marina fees are nasty, as is insurance etc.... but you only live once. I am going to my friends funeral on wednesday who i played footy with in my youth, he was 56 like me.

[Dignity]

Sounds like you've found your niche, enjoy it. Sorry to hear about your mate, that is way too young.

[Lovey80]

My father had a stroke this year at the age of 56. Standing there at work just after knock off and bang. He’s still kicking but can’t talk, no use of the right arm. Very little ability to walk. It’s a long road back for him. I’m reassessing my priorities as well.

@Qlder1. Did you make a decision on the lithium battery set up?

[Qlder1]

My father had a stroke this year at the age of 56. Standing there at work just after knock off and bang. He’s still kicking but can’t talk, no use of the right arm. Very little ability to walk. It’s a long road back for him. I’m reassessing my priorities as well.

@Qlder1. Did you make a decision on the lithium battery set up?

Not yet, 2 of the 210A lead acids are new. It has an existing solar setup with guessing 2 x 100W panels, and a newish Renogy 40A controller that charges at @ 15A when the sun is out. The controller will work with Lithiums so might be worth trying that first. Some of the lithiums I was looking at have gone up in price considerably.
So far have added a new sounder and radar, 32" tv in saloon which swings out to face the cockpit and mirrors sounder for fishing, rocket launcher and outriggers. Also tidied up lots of wiring. I started polishing the sides but man hard job.

Sorry about your Dad Lovey, it must be hard for him, as well as your whole family.

[ranmar850]

Read through the whole thread, envy you with the bigger boat for extended liveaboard. I'm also an electrician, non-practicing for a while, just training in it nowadays part-time. I dived into the lithium world a few years back, with a complete upgrade for my camping setup, as well as a separate setup for the ute.
Some may recall I had engineered it to be easily transportable into the boat from the ute, for extended trips. My wife and I camp on the Reefrunner for up to 10 days at a time. The standard setup of two lead acid with Start/House/VSR/parallel switch was installed by me when I fitted the boat from new, wish I knew then what I know now. It has to supply a fridge running a BD-50 compressor, andd a small Travel Buddy oven. The House battery is only effectively 75ah, and being lead acid, only has a bout 30ah useable, so is not really big enough to use both if we have been anchored up all afternoon on a cloudy day. ( 120w of solar on the roof). The transportable part of it in the ute consists of a 75ah Baintech Slimline controlled via a Renogy 50aDC-DC/MPPT controller. it's all mounted so as to be easily removable and into the boat, whole thing takes maybe 15minutes at the start of the trip. The battery normally powers a 45l Engel which sits in the back seat of the extracab. In the boat, I mostly use it to run the Travel Buddy, then maybe the fridge overnight. Now i have started taking the Engel along as well on the longer trips, as a freezer, so I really need the upgrade.

I am fitting a Baintech 110ah Slimline to the boat, ( dispensing with the lead acid House) running via a Victron 30a DC-DC(isolated) The DC-DC ( mounted up in the cab) will be supplied from the start battery using the existing 25mm2 House supply, deleting the House switch and VSR down the back (fused 100a off the battery) . The battery (mounted in the cab, uses the same mounts which fit the 75ah one) will supply the House load via a latching relay ( which can be concealed) controlled from a push button, much tidier than having to find somewhere to mount a battery switch. The current MPPT solar controller will output the same.
The Renogy DC/DC/MPPT combined unit works fine ( I have 2, one for the ute, one for the camper) , but monitoring it is a pain. They have a Bluetooth module, and an excellent app, but the BT connectivity to my almost new phone is spotty and unreliable at best. Was the same with my last phone as well. They have given me new BT modules, didn't fix it. So i just have to rely on separate battery monitors. I have a chinese cheapy, knock-off of a Victron BMV-700, in the camper, works fine. In the ute, I have a Victron Smart Shunt, which uses the Victron app to monitor, also works perfectly. For the new boat instal, I will fit a Victron BMV-700 as a monitor, as I have a 52mm hole to fill in the cab, due to the fuel gauge on the boat now being redundant.( Whole other story)

So, to sum it up.
1) For a large boat, you can mount gear in a dry position, so you dont need the water proof stuff like Redarcs

2) Victron stuff is just plain excellent, reliable and excellent functionality. The one app covers all of their Smart(BT) stuff, and has no problems linking to three separate devices at once. If you want to have a play, download the VictronConnect app from the play store. On the top left hand corner, tap the 3 horizontal bars , then tap Demo Library. This brings up full simulations of every one of their Smart devices, and you can see how it functions.

3) Renogy BT is a PITA, other wise devices work fine.

4) Victron battery monitors are a great accessory, get the dumb ( BMV-700 ) version, or the higher spec ones which are both BT and panel monitored.

5) Combining your solar controller and your DC-DC charger may not be the best idea, as you are putting all your eggs in one basket. Victron state this is why they don't do it. Cynics will state they only want you to pay twice--perhaps, but solar controllers are as cheap as chips, this is one area I wouldn't bother spending big money on.

6) With all the solar in the world, you will still need some form of backup generator. Just as true on the sea as on the land. My camping setup ( lots of lights, 60l Engel and 130 litre 12/240 freezer) runs perfectly on solar alone and 150ah of Amptron litium battery. Until you get cloud all day, then you are running the generator until the battery is charged up. And lending it to to other campers with no generator and the same problem Unavoidable. So you will be running a main motor to charge if it is cloudy and you are not steaming around all the time.Especially if you intend to run an inverter.

7) Inverters are power-sucking battery destroyers. As an electrician, you can do a simple calc- take the AC current draw, then multiply it by 20 to get the 12v DC draw. Rough but ballpark, plus the standby current. Get as much 12v stuff as you can.

8) Keep all your cable sizing up, voltage drop is your enemy.

9) Your 120amp alternators shouldn't have a problem. DC-DC chargers will keep the idle load down--running direct from alternators into LIFePo4 batteries is where people fry alternators, particularly at idle. Have you seen this video?
https://www.youtube.com/watch?v=jgoI...=VictronEnergy If you are dubious, the Victron Smart stuff has the ability , via the VictronConnect app, to configure at what voltage , sensed from the alternator, the DC-DC starts to take charge.

10) Running paralleled DC-DC chargers into one big House bank is no problem.

To finish off, here is a drawing of what I intend to do. Just single line on the supply side, no detail of individual sub-circuits. Much smaller scale than yours, but principles are the same. I'm running an anchor winch and a craypot winch. TinyCad is really for electronics circuit drawing, so some of the symbols used are a bit naff for general power, but you'll get the idea. EDIT--I just spotted a mistake in the drawing, I'll fix it and repost--EDIT--Fixed




Fixed

[Lovey80]

Just to throw this out there because I’d recommended a product without testing it myself. I personally wouldn’t use the PowerPaul batteries.

Yes he does great due diligence before assembling his product and on delivery you will get exactly what he advertises. But he uses an active balancer that is active all the time. Which means that even in the flat area of the voltage curve the balancer can potentially imbalance the pack to a point where it will struggle to rebalance the pack when it charges right up.

This is a deal breaker for me and I’ll be buying my own cells and using a Neey active balancer that can be programmed to turn on exactly when I want it to. I’ll probably just go with a Daly BMS in 250a if JK-BMS don’t have a similar product when I do my build.

[Qlder1]

Thks ranmar and lovey for the replies, I really appreciate the advice. I am in no real rush to jump in with the lithium upgrade, I have so many other things I want to do to this boat, and actually the existing stuff works pretty good surprisingly. If I continue with the gas cooking and engine HWS I could see myself doing week long trips as is with no dramas. A small genset would be required but no biggie.

What has surprised me a little though is the friendly people I have met at the marina. I really need to change this thread to "buying larger boat and the enjoyment of fishing /boating in a different way to trailer boat fishing" haha

[Lovey80]

No worries. What Marina is your home base?

oh and pics of the boat please.

[Qlder1]

scimitarpic2.jpgKeppel Bay. Seven Scimitars there now by my count. I only have before pics mostly. This one after I added Rocket Launcher and radar. Have put 4.5m outriggers on since.

Attachment 126133

btw I did my first proper fishing trip in it, Friday arvo overnighter. It was really good. We caught some good fish, Red Jew, Grunter, S and P trevs, And a couple of large Cobia. Anchored all night in 45m of water no probs. The electrical system has gone up in my priority list. Voltage was average by @ midnight with only fridge, freezer, sounder and a few lights on. I am thinking that the solar is only just keeping up with 24hr fridge/freezer power requirements and soon as anything else is used it starts dropping. Alternators are working but only a 2 hr run wasn't enough to help much.

[ranmar850]

This is where you start to see the limitations of a system. On the topic of discharge rates, you've probably picked up on the fact that LiFePo4 has a much flatter discharge curve and you are able to utilise more of it than on lead acid. The statements that they are twice as good as lead acid for any given a/h rating are an exaggeration,IMO, but they are easily at least 50 % better without driving them down into the discharge level where you are starting to shorten their service life. At 50% DOD with lead acid, you are effectively flat, lights are dull, compressor-driven fridges are struggling, you are well down into the low 11's. Same level of DOD for a lihtium, you are still well over 12v, lights are bright, fridges are happy. I replaced 200ah of AGM with 150 ah of litium, chalk and cheese, absolutely no comparison.

On the subject of charging, you just need to look at ah consumed vs ah replaced by charge. This is another area where lithium shines--you effectively have to just put back in what you have used, whereas the old chemistries actually need more. And you don't need to worry about Absorbtion, which is important for lead acid/AGM. If you don't get into Absorbtion, you are not getting fully charged. With Lithium, the Absorbtion phase is essentially meaningless, once you have finished Bulk charge, you are at 95% and essentially fully charged.
If you have 2 x 30A DC-DC chargers, one each motor, you will be putting 120ah of charge into your batteries in 2 hours. That should be more than enough to power a boat safely overnight with plenty of reserve, if using lithium. if your lead acid House cells are feeling their age, and that is something which creeps up on you, you won't be getting them fully charged.

As you are in a marina, do have have shore power ? Can you have your batteries on charge so you essentially leave for the overnighter already charged? That will help for the first night, but casual cruising where you tend to spend a lot of time at anchor means you aren't getting a lot back in without running a generator. This is where good solar comes in, but, of course, you still get your cloudy days, and panels mounted flat on a roof are nowhere near as good as panels you can angle towards the sun for more efficiency. And that's without issues of shading you might get from all the hardware mounted on the hardtop.

[Qlder1]

Some pics of the changes I have made in the last couple of months
scimbeforeafter.jpg
new clears, rocket launcher, little outriggers, some new decals for the sides. Still needs a proper polish but that can wait till it comes out in a year or so.
battschgers.jpg
Attachment 126383Attachment 126384
Added 3 Victron chargers, 1 x 15A 240v and 2 x 30A dc/dc. Went a bit cheap with Batteries and inverter , Giant 340A x 2 and a 3000W Renogy inverter. 2 x 40A cb and a 300A fuse.
backdeck.jpg
Added a larger cutting board, extra rod holders, retractable deck wash and a small tackle locker.
ladderbeforeafter.jpg
Spaced out the Flybridge ladder to fit an esky/freezer.
scimtv1022.jpg
32" smart tv. It swings out into doorway but not overly practical as a sounder. I ended up fitting a tablet holder on the door and use 10" tablet instead. Good for netflix though haha.
dashbefafter.jpg
new MFD and updated the switches. This thing did not have nav lt switches on flybridge only in switchboard downstairs. Also added a tablet holder and usb port to monitor chargers and batteries etc
appliances.jpg
microwave and mini air fryer. Air fryer uses @ 90A, microwave a bit less. Only used them in marina so far, but could be used sparingly away from AC. Kettle is strictly shore power.
drinkholder.jpg
removed the ancient Navman sounder and replaced with a drink holder. Probly need a new holder soon its getting a flogging haha.

[Dignity]

I'm sure it's looking great however the pics aren't working for me.

[Lovey80]

Just to throw this out there because I’d recommended a product without testing it myself. I personally wouldn’t use the PowerPaul batteries.

Yes he does great due diligence before assembling his product and on delivery you will get exactly what he advertises. But he uses an active balancer that is active all the time. Which means that even in the flat area of the voltage curve the balancer can potentially imbalance the pack to a point where it will struggle to rebalance the pack when it charges right up.

This is a deal breaker for me and I’ll be buying my own cells and using a Neey active balancer that can be programmed to turn on exactly when I want it to. I’ll probably just go with a Daly BMS in 250a if JK-BMS don’t have a similar product when I do my build.

i now take back everything I said. This guy managed to get heltek to make him custom 5A active balancer that turn on exactly at the right time towards the top of the charge curve (3.4-3.43v) and back off again when it drops below that. This is perfect for LifePo4 batteries and because it turns off when the charge curve becomes flat again. This prevents it from causing an imbalance. I’ve ordered 3 of them to test out.