Author Topic: Chargers, Inverters, solar & wind  (Read 207 times)

SorinCT

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Chargers, Inverters, solar & wind
« on: May 22 2020, 18:36 »
Good day gents! First of all i want to thank you all for the large amount of information shared on this forum.

I am in need of some suggestions for upgrading the current "stock" charging and 220v system onboard my C36 2002.
Current set-up is with the standard alternator, diode splitter, charging 1 x 185 Ah house battery and 1 x 85 Ah engine starting battery. Shore power is provided to a 220v socket under the nav table and another one under the STB settee, powering a "no-name" battery charger (looks like Croatian origin). The charger is not smart and is wired only to the house bank.

In the near future i am planning on adding 2 x Optima AGM batteries, a new "smart" charger, inverter and a MPPT solar charger. Also, it might be wise to install some type of ACB on the shore power line.

As of previous experience with miss-matching battery sizes, types and specs, the charger will not work effectively, and to my best guess will require several outputs (1 - current house, 2 - both optima's (or single-up each), 3- starting battery). Redundancy also dictates the need for a battery selector just in case the engine won't crank from a faulty battery.

The inverter would need to be connected to the deep-cycle batteries and supply some 1000W power to appliances. A solar MMP is required for charging from solar panels.

Can anyone share some wisdom regarding this subject?
Below my ideea for the layout so far.

Symphony

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Re: Chargers, Inverters, solar & wind
« Reply #1 on: May 22 2020, 20:16 »
Welcome to the forum

Most proper marine chargers will have independent outlets to charge 3 banks. Typical capacity for your suggested battery set up would be 25A, but if you are going to depend on 220v charging a lot you might want to go for a 40A. However if you fit the largest house bank possible and don't run them down to low a 25A will be fine. It is worth setting the charger to the engine start, although in reality this will rarely need any extra charge as a few minutes engine running will keep it topped up. 85AH is fine for the engine and for the house bank fit 2 of the largest AGMs you can get in, which will probably be around 130AH each and wire them in parallel as one bank. My choice would be to ditch the diode splitter and replace it with something like a BEP Marine cluster which uses a VSR and also wires each bank independently but with a paralleling switch for emergency use. Not sure a smart charger is really worth it for AGMs They are useful for boosting charge voltage to lead acid batteries, but AGMs generally charge faster anyway.

SorinCT

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Re: Chargers, Inverters, solar & wind
« Reply #2 on: May 22 2020, 20:31 »
Thanks for the input! I was considering a smart charger due to the fact that it is not so easy to find a 2 or 3 output charger without "smart" functions. On my previous boat i was running a Ctek M200 which was quite good but due to the fact that plans were changing a lot, it ended up not working correctly because i had a total of 4 batteries in 3 banks, some gel, some AGM, different capacities and functions, all hooked up to a alternator+charger+wind+solar octopus  ;D

Symphony

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Re: Chargers, Inverters, solar & wind
« Reply #3 on: May 22 2020, 23:41 »
You need to look at proper marine chargers, not automotive ones like Cetek (I know they claim to be marine!) Look for makes such as Sterling, Cristec (which are fitted at the Bavaria factory), Victron,  Mastervolt, Quick, Synergex, all of whom do 3 output chargers in the 20A to 40A range. More expensive because they do the job. These will all be programmable to suit the batteries they are connected to, so you can have a lead acid start battery and AGM house, plus you can use the third to charge an extra battery such as for a bow thruster. That is what I have on my 33 with a factory fit Cristec 30A, a 90ah start, 3*90ah house bank and 90ah bow thruster, all charged independently.

You can buy Sterling and Quick chargers (and the BEP Marine cluster) from www.force4.co.uk but all the mail order chandleries will have similar in their range.

Craig

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Re: Chargers, Inverters, solar & wind
« Reply #4 on: May 23 2020, 02:13 »
I agree with the basics of the advice above.

Just a few additional thoughts:-
1. I don't know about Britain but Lithium batteries now appear to be cost competitive with lead acid. This has only happened recently so it might be a good time to consider the change.
2. With a switch to start your engine from house batteries in an emergency you may face the problem of not resetting the switch and risking flattening both battery banks. I keep jumper leads on board and have had to use them once in 10 years to start the engine. Much cheaper and safer option.
3. For a change like you are contemplating, it might be a good time to review your sailing demands on power to determine whether your battery capacity is adequate.
4. The rate of charge from shore power is probably not critical. If you are plugged in to shore power, then you are probably staying there for some time.

Craig
" Shirley Valentine"
Gold Coast
Australia

SorinCT

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Re: Chargers, Inverters, solar & wind
« Reply #5 on: May 23 2020, 10:15 »
I guess i forgot to mention that i already have the 2 Optima AGM so in my opinion it's best to either expand current set-up with them or swap with the 185Ah existing house.
Regarding the switch you are right, it may be overlooked. On the other hand, in case of emergency, fiddling with jumper cables down below might not be so safe either.
Demand for power will slightly grow but i am unsure how much at this time. Will add full new nav equipment (mfd, autopilot, quantum radar, ais transducer, etc), plus maybe some sorts of small tv, etc..
As for this year and maybe next shore power will be available on a daily basis for minimum but i expect leaving the dock for a couppe of days (hence the solar and wind).

Just as a bit of context, boat is in the Black Sea, Romania. Unfortunately the chandlery here is at a minimum and some parts cannot be easily obtained. 

Symphony

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Re: Chargers, Inverters, solar & wind
« Reply #6 on: May 23 2020, 10:17 »
Not sure lithium are really practical for normal cruising boats when you can get good capacity at relatively modest cost with AGMs

Don't understand your point about an emergency switch. There are 2 ways of wiring one. The first is using a cluster like the one I suggested which allows you to connect all batteries as one bank. The second is a separate switch to connect the house bank straight to the engine in an emergency. To use, if your start battery is flat you just switch and start the engine then turn it off and the engine is now charging both batteries. What is so difficult about that? - far easier than grovelling around in the battery compartment trying to attach jump leads or even impossible on a boat like mine where the start battery is in a cockpit locker and the house batteries in the saloon! Also fail to see how you can flatten the batteries when the sole reason for using it is to start the engine which will not take much out of your house bank.

You are right about the 220v charger as the charge drawn is a function of the batteries' capacity to absorb the charge, which is as a rule of thumb about 10% of its capacity hence the popularity of chargers in the 20-40A range.

Yngmar

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Re: Chargers, Inverters, solar & wind
« Reply #7 on: May 23 2020, 10:58 »
0. Consider your battery bank layout. Instead of having 2 house banks, which is nothing but trouble and little benefit, I'd go for a single, bigger house bank (add 1-2 more of those AGMs). This will also help the batteries survive if you actually use your 1000W inverter near that load.

1. Forget the battery combiner switch. Replace the out of date technology of the diode splitter with a Victron Cyrix VSR (<50 EUR), which also has a very useful feature where it doubles as battery combiner switch, without the extra set of thick cables. Both problems solved with minimal wiring :)

2. Shorepower Charger: Sterling Pro Charge Ultra. Bit pricey, but does everything and will keep your AGMs happy. I would recommend them over the Victrons at certain sizes, because Victron has gaps in their line-up, awkward connectors and the larger models aren't particularly boaty (and too big in size).

3. Solar charger: If your solar capacity is anything more than a trickle, Victron MPPT is the obvious choice.

4. Shorepower must have an RCBO and separate breakers for shorepower charger, outlets etc. are a good idea. You also need a three-pole(!) selector switch for selecting between shorepower and inverter for the outlets.

5. If you want to get more out of the alternator, an A2B charger is the way to go these days.
Sailing Songbird (Blog & YouTube)  ⛵️ Bavaria 40 Ocean (2001)

SorinCT

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Re: Chargers, Inverters, solar & wind
« Reply #8 on: May 23 2020, 11:28 »
I was looking into the Cyrix VSR technology and it makes sence to use one instead of the diode splitter. I already have a spare Victron Argo FET splitter just in case I cannot source a Cyrix VSR.

Sterling products look good specs-wise although pricy. Their product lineup has also a Lite version (2 outputs and less certification vs Ultra). Best practice dictates a charging capacity of 10%. I might need close to 40A  peak charging current but i usually avoid running down the batteries and the solar would help out too.

Capacity of solar system will be probably in the 150-220 range, with 2 panels mounted on the aft arch in parallel (If shading from the Radar, turbine etc. can be avoided). Victron Energy BlueSolar MPPT 75/15 seems to fulfill all requirements.

Lazy Pelican

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Re: Chargers, Inverters, solar & wind
« Reply #9 on: May 23 2020, 11:38 »
Hi Yngmar,

Interested in your Victron Cyrix recommendation. Looking at them it looks as if they’re a direct replacement for the standard Bav splitting diode in the engine bay.
I’m looking at a Cyrix-ct 120A. Is this correct for a B39 2006, with original alternator and 3 x 140AH domestic batteries?

sunshine

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Re: Chargers, Inverters, solar & wind
« Reply #10 on: May 23 2020, 12:24 »
As Yngmar says - on a 2002 boat (and more recent) the weakest point is the diode splitter which prevents the house bank getting anywhere near fully charged. VSR (good and inexpensive) or A2B charger (even better although a bit pricier) are priority mods on older boats. If you try to buy an old-school diode nowadays they even come with a warning that they wont fully charge batteries.

Symphony

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Re: Chargers, Inverters, solar & wind
« Reply #11 on: May 23 2020, 13:44 »
You don't say what your usage pattern is. The requirements for a "weekend" sailor are very different from a long distance cruiser or a liveaboard.

If you use your boat at weekends or for 2 or 3 days at a time with perhaps a longer period away once or twice a year then a system such as I suggested originally, perhaps with the addition of solar is more than adequate. The starting point is to do a usage audit of your typical consumption. The biggest power user is the fridge then when sailing the autopilot (and radar if you have it and use it). Other potential big users are navigation lights at night and anchor light then interior lights and entertainment. There are many ways you can reduce consumption such as extra insulation of the fridge, keeping it full with really cold things like frozen bottles of water and chilled beer; LEDs for all lights, minimising load on the autopilot by trimming sails well etc. 

In my experience in this pattern of usage in both the UK and the Med is that daily current draw is in the region of 60-80AH. A battery bank of 270ah discharging to 50% (best for long life) gives a safe capacity for 2 days without recharging. An hour engine running will put back at least 20ah, solar in your environment probably 10ah increasing safe capacity by another day. In reality most people motor more than one hour a day if they are on the move every day, so capacity really only becomes an issue if you spend long periods at anchor in which case you do need to either increase your bank capacity or solar/wind or both. The reason for working on 50% discharge is that although AGMs take charge quicker, actually getting them back up to 100% is very slow. So work on leaving 50% and concentrate on getting back as much of your consumption as possible each day.

As for shorepower charging, there really is little need for charging the start battery as it should always be fully charged so if you can't get, or don't want to spend the money, a proper multi output smart charger, just get a simple 10a single output for your AGM bank. If you sail at weekend and then leave the boat on shorepower for the rest of the time, the house bank will be fully charged. In fact if your pattern of usage is as suggested above it will be fully recharged in less than a day. Higher output chargers only make sense if you stay on shorepower while using things like microwaves, hairdryers etc through an inverter plus the fridge when you want the charger to keep pace with the increased consumption. However in reality it makes sense in these situations is to use 220v direct. A 10A will keep pace with the fridge and lights if you have LEDs.

It really is worth fitting the BEP cluster. The basic Bavaria system is poor by today's standards with just the one isolator in the negative feed and the diode. You can leave the isolator in but in the on position with the handle removed. The cluster costs under £200 and gives you a VSR, independent isolators for each bank and a parallel switch. I have fitted 2 of these, one in my old 37 which is much like your boat. It is easy to wire because it can all be done in the battery compartment, although it makes sense to have the switches on the outside.

AGMs have a very low self discharge rate so you only have to think about how you replace your usage. in the last 4 seasons with my 33 that has a 270ah house bank, I have never got remotely near running low on capacity, even though I always stay at anchor and run the fridge all the time. I put the shorepower on when I get back but it normally only puts out 3 or 4A which means it is just topping up the last bit, and fully charges in less than a day. Over this winter from November until now I have put shorepower on only twice as the bank has never fallen below 12.7v

Hope this helps