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Considerations for Upgrading Electrical System

5K views 25 replies 9 participants last post by  Maine Sail 
#1 ·
I purchased a 1991 Contest 35s sailboat at the end of last season, and she's now on the hard, and being refit for this coming season. Which includes an electrical refit. Currently, all 3 Group 31 batteries are housed in an open top fiberglass battery box with straps, (factory installed), under the aft-berth. She has the factory DC panel, and an added 120v shoreside system, with a 30amp inlet and a separate single main AC breaker, (which isn't a double pole breaker). Her electrical inventory includes;
  • Starter Battery - West Marine Seagel Deep Cycle Gel 97
  • House Bank - 2 Deka Dominator (8G31DTM) in parallel
  • Perko 1-2-All Battery Switch
  • Amptech 125/108 High Performance Alternator
  • Heart Interface incharger 3 stage Alternator Regulator (84-2006-00)
  • Guest Charge Pro 5/5 10amp Charger
  • 2 - 80 Watt MBF80 Solar Panels
  • Xantrex C12 12 amp Solar Charge Controller
I can appreciate the logic in working backwards from accurate calculations of how much electricity needs to be consumed, and designing an electrical system to support that consumption. However, there are a number of electronic upgrades that I want to add in the future, such as air/heat, water maker, television (DC), upgraded entertainment system (Fusion MS-AV700i), and updated nav electronics, but initially this refit will focus on upgrading the electrical foundation of the boat. I've been trying to identify the components I should consider upgrading, (mostly after reading threads here), but I still have some questions.

A house bank of 3 AGM Group 31 batteries fits in the existing battery box, and can provide 375ah. If I could make the box deeper, I could accommodate 3 Group 30HTs for a total of 450ah, but the original box would probably need to be cut out, and a custom box built. This may force me to go with the 3 Group 31 375ah house bank, then house a single AGM Group 31 100ah starter battery close by, in it's own battery box or tray. With the switch to AGMs, I thought that I should upgrade the engine with a serpentine belt kit, and a higher output alternator with regulator, (150amp+), as well as upgrade the charger. I also wanted to upgrade the panel to a combined AC/DC, Blue Sea Systems 360 panel, and add a Blue Sea Systems Dual Circuit Plus Battery Switch with an Automatic Charging Relay.

The current system appears to provide AC power to only the water heater and the 2 AC outlets on the boat, but only when the boat is plugged in. As part of this refit, I do want to add a couple more AC outlets, but I also want to add DC USB charging outlets for charging tablets and phones, (and in the near future for laptops, too). I also want to add DC electronics where it makes sense, such as the JVC DC TV when I get to that project. Even though I'm trying to design a system that minimizes the need, I believe I will need AC power underway. Which means adding an inverter to this system. At this point I'm curious about a few things;
  1. Is adding a serpentine belt kit, (and alternator), a better choice than simply adding a higher output marine alternator, (or keeping the existing one)?
  2. Are high output marine alternators from Electromaax, and Sterling Power, good ones to consider for this application, (since they price out less than Balmar)?
  3. Is it sensible to combine inverter and charger by installing something like the ProMariner TruePower CombiPS for this application?
Any other suggestions, corrections, etc., are welcome as always.

Jason
 
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#2 ·
Is adding a serpentine belt kit, (and alternator), a better choice than simply adding a higher output marine alternator, (or keeping the existing one)?
>>A "serpentine" belt really means a serpentine ribbed belt, and any kind of ribbed belt transfers power better than a V-belt. Somewhere arounds 100A a v-belt starts slipping no matter what you do, and a ribbed belt is the only way to go for reliable transfer over that. So yes, absolutely.
And if you need more amps, the bigger alternator too.

Are high output marine alternators from Electromaax, and Sterling Power, good ones to consider for this application, (since they price out less than Balmar)?
>>Owners all seem to love them. Biggest question being, what can you shoehorn into your engine compartment, usually.

Is it sensible to combine inverter and charger by installing something like the ProMariner TruePower CombiPS for this application
>>That's partly a matter of philosophy. If you have integral units, and one goes bad, you have to send out everything for repair. OTOH integral means more compact and usually less money for the equipment and the installation.
 
#3 ·
First, I am not an electrical expert.

But I would be very tempted to switch to lifepo batteries instead of lead. They cost more, but provide more power, and faster bulk charging, which will minimize the run time of those big alternators once the AGM batteries switch to absorption mode.
 
#4 ·
First, I am not an electrical expert.

But I would be very tempted to switch to lifepo batteries instead of lead. They cost more, but provide more power, and faster bulk charging, which will minimize the run time of those big alternators once the AGM batteries switch to absorption mode.
This 3700 response thread on Cruisers Forum should turn off anyone but highly advanced electrical engineers on any kind of Li battery.
 
#6 · (Edited)
(Given the scope of the electrical refit, I considered moving up to lithium batteries. However, I think that this time, I'm going to focus on upgrading the bank size, adding a combined AC/DC panel, upgrading the wiring, etc. Maybe the next refit I can consider upgrading to lithium batteries.)

Thanks hellosailer. You at least confirmed what I understood by my limited online research. That the serpentine ribbed belt is a more efficient power transfer arrangement, and that there are several good high output marine alternators available.

Jason
 
#7 ·
I agree with the serpentine belt for an alt of the size you want.

I recommend you do not use the Dual Circuit Plus Battery Switch. First, it's intended use is for boats with equal size banks such as small fishing boats with one battery in each bank. The second reason is that it gives you no option when the start battery is discharged but to combine the banks. A discharged battery should never be combined with a charged bank - especially with Agm batteries. The inrush from the charged bank to the discharged bank could leave you without a bank capable of starting the engine. Your existing 1/2/both switch could be kept if you wish, assuming its condition is good. I would install 3 simple on/off switches. One each for start and house and a third to allow either bank to be used for either use independent of the other.

I would also buy a separate inverter and charger for the reasons posted above.

What is your intended AC use away from the dock?
 
#8 · (Edited)
Thanks Brian..

I appreciate the explanation of the battery switch. Would this series switch accomplish what you described in terms of properly separating the banks?

Lastly, I'm not sure what AC power I would need underway. I can see using the AC outlets while at the dock for things like power tools, but underway, maybe use them to charge up a laptop. Perhaps an inverter is not something to add to the project this winter?

Jason
 
#9 ·
Yes, that switch combination will work fine. That is what I was describing in a very neat installation. Wiring diagram is below.



As far as an inverter being used for a laptop it is pretty inefficient. Especially when it is large enough to use for power tools as well. For a laptop you are better off to buy a car adaptor designed for one and if you have a large inverter use it for heavier loads other than the laptop.
 
#12 ·
I can appreciate the logic in working backwards from accurate calculations of how much electricity needs to be consumed, and designing an electrical system to support that consumption. However, there are a number of electronic upgrades that I want to add in the future, such as air/heat, water maker, television (DC), upgraded entertainment system (Fusion MS-AV700i), and updated nav electronics, but initially this refit will focus on upgrading the electrical foundation of the boat.
Will you have a fridge? Without one it sounds like your current electrical system is somewhere between overkill and gross overkill.

Most electronics have a fairly small drain. So does my Webasto heater (it is about 1 amp). The high drain items would be a fridge, water maker (don't most run off of the engine though?) and only one of those is listed.
 
#13 ·
Will you have a fridge? Without one it sounds like your current electrical system is somewhere between overkill and gross overkill.
I do have a Frigoboat refrigerator but I don't mind overbuilding the system this winter. That way when I get to adding the updated entertainment electronics, cell and/or wifi boosters, and start looking at water makers and updating the nav electronics, I know I'll have the headroom.

Jason
 
#14 ·
I find that most inverters are used for convenience outlets (plugging in a laptop or toaster or blender). The heaviest load I usually see is a microwave. (which does draw alot) I'm now of the school of thought that on boats of this size I would install a large inverter for things like running tools , microwave etc and a smaller unit setup in a convenient place to plug in a laptop etc. Beware of the plug in inverters as those plugs don't do well under heavy loads. Depending on how you use the boat (spending alot of time at slips vs anchoring out) you may not even need the large inverter.
On hot water, most boats only use the electric element at the dock and use a loop from the engine cooling to heat the water underway or at anchor (unless you have a genset).
 
#18 ·
I would install a large inverter for things like running tools , microwave etc and a smaller unit setup in a convenient place to plug in a laptop etc.
You can get DC power supplies for almost every laptop on the market. These will be more efficient than using an inverter to convert DC to AC, just to have the laptop power supply convert it back to DC.

I keep a very small inverter onboard for my DSLR battery charger. Everything else necessary for cruising on my boat is DC.

That way when I get to adding the updated entertainment electronics, cell and/or wifi boosters, and start looking at water makers and updating the nav electronics, I know I'll have the headroom.
You can get the real world loads for those today, figure out how much you'll use them, and plan around it. I have no experience with water makers and believe that they are big load items, but the rest of those items are pretty low load.

There is a downside to having a too large DC system. Batteries are expensive and heavy. Solar Panels and Alternators that can support those batteries are also expensive (and the panels get in the way). I believe in sizing things right instead of big.

In cruising this summer I never saw my modest 2*Group24 house system (180 AH raw, 90 AH usable) drop below 85% charge, most days it was near 90% charge. I ran a nav system almost non-stop, kept two tablets and a laptop charged, used VHF for 6-12 hours a day and the radio/MP3 player quite a bit. We have LED lights everywhere. There is a 30w solar panel and 55 amp alternator. I didn't plug into shore power. If I added a fridge I'd clearly want a bigger DC system, but I don't think I'd ever need a huge one.
 
#15 ·
Thanks Colin..

I was guessing that most marine inverter uses underway, involved traditional home appliances, (more or less). I'm thinking at this point I'll hold off on an inverter. Down the road, if needs arise, I can always add one.

Jason
 
#17 · (Edited)
Starter Battery - West Marine Seagel Deep Cycle Gel 97
House Bank - 2 Deka Dominator (8G31DTM) in parallel
Perko 1-2-All Battery Switch
If you stay GEL for start you will need to use a product like the Balmar Duo Charge to feed the GEL proper charging voltage.

The Group 31's are Deka GEL batteries and the same as the West Marine start battery. Deka/East Penn makes the batteries for West Marine..

Amptech 125/108 High Performance Alternator
You have not said what engine this is on but this is a good alternator. A tad old school and based on the Delco 10DN but otherwise a good alt. Ideally if you have a single belt it should be dialed back to about 90A and it will purrr along there all day long.....

Heart Interface incharger 3 stage Alternator Regulator (84-2006-00)
This is a poor excuse for an external "smart" regulator. Pretty featureless, pretty "dumb" for a "smart" regulator..... I would strongly advise moving towards a Balmar ARS-5 or better yet an MC-614 which gives you the ability to derate the alternators output to match your belt, use alternator and battery temp sensing etc..

Guest Charge Pro 5/5 10amp Charger
Sent it to the dumpster where it deserves to live....

The ProMariner Pronautic P or Sterling Pro-Charge Ultra are both EXCELLENT chargers suitable for AGM. These are the same charger sold under to differnt brands (co-developed)

They come standard with 11 pre-set programs plus the ability to create a custom profile. The algorithm is also a smart adaptive learning type which is far smarter than timed algorithms. They also ship standard with a battery temp sensor. By far they have the absolute best remote control display of any battery charger I have ever installed. Worth the money..

2 - 80 Watt MBF80 Solar Panels
Xantrex C12 12 amp Solar Charge Controller
Sounds like a couple of inexpensive Chinese panels and a PWM controller. Never been a big fan of the C12 but it works.. It will work fine, but you could easily do better. If you want to do better I would start with the controller, if you are inclined to do so....

A house bank of 3 AGM Group 31 batteries fits in the existing battery box, and can provide 375ah. If I could make the box deeper, I could accommodate 3 Group 30HTs for a total of 450ah, but the original box would probably need to be cut out, and a custom box built. This may force me to go with the 3 Group 31 375ah house bank, then house a single AGM Group 31 100ah starter battery close by, in it's own battery box or tray.
Can you explain what you are looking to get from AGM's? Is the boat on a mooring or at a dock? Only Lifeline can get you to 375Ah with 3 X G31 and this is not inexpensive.... I prefer GEL batteries to AGM for longevity but Lifeline and Odyssey are about the best AGM's you can get. If staying with Deka buy their GEL batteries not AGM unless it is only a start battery....

With the switch to AGMs, I thought that I should upgrade the engine with a serpentine belt kit.
This is never a bad idea but can get expensive. Unfortunately the AmpTech will not work with the E-Maax or Balmar serp kits and you need an alt designed for those kits, offsets are different, which means more money...

and a higher output alternator with regulator, (150amp+), as well as upgrade the charger.
Keep in mind that a 150A alt should ideally be run at about 120A for the longest life. This is set up in the regulator.. Your 125A alt can be run at about 90A on the stock belt you likely have. This would be 80A if 3/8".

This is a LOT of money to gain perhaps 30A in bulk... Not a "priority" investment IMHO..

At 90A your AGM's will like hit absorption voltage, depending upon where it is set, at about 80% SOC. On a 375Ah bank this means you need to replace approx 110Ah's in bulk or slightly over an hour with your current alt set up for 90A.

At 120A you will do bulk in slightly under an hour. You are really talking about shaving perhaps 15-20 min off bulk for a $1500.00 +/- investment.. If that seems wise to you wallet by all means go for it...

The time from hitting absorption to full charge is identical no matter how large your alternator. Once you hit absorption voltage your batteries decide how fast they can be charged not your alternator or regulator...

I also wanted to upgrade the panel to a combined AC/DC, Blue Sea Systems 360 panel, and add a Blue Sea Systems Dual Circuit Plus Battery Switch with an Automatic Charging Relay.
Not a big fan of the DCP switch as it leaves no way to isolate a failed bank and leaves your only option to combine a good battery with a potentially bad battery. The three switch method is good as is a modified 1/2/BOTH...

For AGM's I generally prefer a programmable device such as a Duo Charger over an ACR but an ACR can work well... AGM's & GEL's like temp sensing because they are less happy with overcharging than flooded batteries. The Duo Charger can give you this for all charge sources feeding it.

I also want to add DC USB charging outlets for charging tablets and phones, (and in the near future for laptops, too).
I generally prefer a standard 12V socket then an adapter that plugs into that and outputs USB. This allows you to use the outlet for both USB and 12V socket style items, if needed. It also allows you to inexpensively replace 12V USB adapters when the current specifications of your devices change.

At a bare minimum you want a dual USB capable of over 4A of current if actually plugging two devices into it otherwise they cook themselves.. For example older iPads used 2.1A and new ones use 2.4A. Plug two iPads into a 2.1A dual USB socket and you will eventually cook it. Easiest just to buy the adapters, and they are CHEAP.....

At this point I'm curious about a few things;
Is adding a serpentine belt kit, (and alternator), a better choice than simply adding a higher output marine alternator, (or keeping the existing one)?
If you were my customer I would suggest holding off and adding just a new regulator that gives you MUCH more control over the alt.

Are high output marine alternators from Electromaax, and Sterling Power, good ones to consider for this application, (since they price out less than Balmar)?
The E-Maax products seem to be hit or miss for some. I have had good luck but others complain of poor service and product issues.

Balmar is top notch as are Mark Grasser DC Solutions alternators. Not a big fan of the Sterling regs or alts but they make some other products which are EXCELLENT such as the ProCharge Ultra battery charger.

There is only ONE good alternator regulator and those are the Balmar's..
Xantrex sells a Balmar reg under their name but PLEASE buy one from Balmar. Why? Because you will get COMPETENT tech support not some phone center dolt who has never touched an electrical product in his/her life and is simply reading out of a "cookbook"...

Is it sensible to combine inverter and charger by installing something like the ProMariner TruePower CombiPS for this application?
Any other suggestions, corrections, etc., are welcome as always.

Jason
For a "keep it simple" system I generally prefer stand alone units to combi's unless you "need" 100A + of charging and 2kW plus of inverter.... For inverters I prefer the Magnum's, Victron's or Mastervolt products because some of them are fully programmable...

A stand alone pure sine inverter can easily be wired to its own dedicated outlet and left isolated of the ships AC system. This is less costly and safer for a DIY install..

If you want to tie into the ships AC system it gets more complicated, to do it right, and more expensive, much more.... Also when the charger side or inverter side fail, on a combi/IC, you lose both devices. This is not all that uncommon and things such as a discontinued simple remote control panel often make a $2000.00 inverter charger inoperable and "scrap metal" material...
 
#19 ·
Maine Sail,

Many thanks for this, (and your many other), informative post. I've come to the conclusion that I'm going to drop plans for adding an inverter, and concentrate on upgrading the battery bank, alternator, charger, and related components for this refit. I'm also dropping plans to use the Dual Circuit Plus Battery Switch and ACR, and go with the existing switch and the Balmar Digital Duo Charge. I also like your rationale for going with 12v lighter outlets, and the idea of revamping the solar setup, (once the underlying refit is done).

In terms of my planned usage for my boat, it's pretty much all new for me. It's my first sailboat, and while I have plans for trips to visit relatives in both Boston and Miami from here in the Chesapeake, (and eventually to do the Atlantic Circle), I'm not sure how many seasons it will take for me to work up to making those trips. I imagine that this coming season she will be mostly at the dock and used for day or overnight trips, eventually stretching out to multi-day trips, as I gain experience.

In terms of the existing electrical system, not only are some of the electrical items you mentioned in need of replacing, I'm inclined to replace as much as I can with new, because some of the prior work wasn't professionally done. Some of the wiring isn't up to code, (wire nuts instead of waterproof-type crimps), so I'd like to clean it all up and have it rock solid. I figure that it's also a good time to start with some new components. You're right in that I wanted to change to specifically the Lifeline 31XT AGM batteries, because utilizing the same battery box, I could get 375ah for my house bank. I had decided to go with the ProMariner/Sterling 50amp charger, and figured that the other main decision would be the alternator.

The boat is powered by the original engine, Volvo Penta (1990), 2003 HE BT, (I'm not sure what the HE BT means after the model number, but it's on the warranty card so I'm pretty sure this is not the Penta 2003T). When I contacted ElectroMaax tech support and provided them some photos of the current engine/alternator, they said that they had the appropriate serpentine belt kit, (PK-VP2003). When I provided the same photos and request to Balmar tech support, they weren't sure. They want me to take photos with a better view of the mount, before they tell me if they have the right belt kit. (Although it looks like the ElectroMaax kit supports Balmar alternators too..) At this point I don't mind spending the money on a new serpentine kit and alternator, especially if it translates to better power transfer, less fuel use, etc.

I do know that as a tech geek, I'm always going to want cool electronics to be part of my boating experience. My plans for her include her being my new writer's office. As a result, I'm considering adding cell and/or wifi boosters as part of this refit. Also, my next electronic refit will include adding the Fusion DVD player, amplifier, new speakers with subwoofer, and a TV. I'm definitely going to want this stuff to be powered whether I'm at the dock or underway. So any work that I do to overbuild my electrical system now may be justified by my expanding usage plans, in the near future.

Jason
 
#21 ·
If you really want to spend the money on a good alt then the Balmar AT165 can't be beat. These are mean a$$ alts that can output tremendous current at low RPM and still run cool!!

Balmar bought AltMount which are all Yanmar kits. They also partner with E-Maax and sell their serp kits but they are all designed by E-Maax. E-Maax sells their kits and the Balmar AT series alternators.... That said I think you would do fine with just a new regulator.....
 
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