Benefits of an inverter

[Maine Sail]

Below is a unit 32,000 Watt Peak.

Lots and lots of Chinese specs but conspicuously absent any sort of UL or CSA, ETL or other legitimate third party testing to verify those claims or to verify the unit is even safe.... Sadly there will be folks that will buy these based on the ratings and price alone...

 

[Gunni]

Gunni, did you remove the switch and if so how did you cover it?

Bob, yes, the remote inverter switch was removed and the hole was covered with a cover plate. The inverter DC disconnect (aft cabin) sits unwired and idle.

 

[Jack Barnes]

Gunni - Those appear to be Lifeline batteries. 6volt? 4D? ?

 

[Gunni]

Gunni - Those appear to be Lifeline batteries. 6volt? 4D? ?

Group31XT Lifelines 12 volt

 

[DayDreamer41]

@Maine Sail I noticed you are very guarded on the subject of both chargers and inverters I don't see any write up's on your How To site, is the reason related to liability? I have looked up ABYC wiring rules #E-11, A-20 and A-25, but sure would be great to have your insight and recommendations.
Incidentally, after reading the code sections I believe that our boats manufacturer did not follow these rules to the letter, or the rules post date the installation. For instance grounding cable size, grounding both AC and DC all the way back to the shore power iso transformers neutral.
Which means I have yet discovered another project......
Mark

 

[MitchM]

our nauticat 321 05 came with an astonishingly expensive mastervolt 1500 W full sine wave inverter. it would not run a hair drier or coffee pot or onboard air conditioner as it was a fancy sine wave model it would nicely power our computer, ham radio and phone chargers, (which of course all came with 12 v chargers.) in 13 years i turned the inverter on once a year to make sure it was working. as for coffee, a tea kettle of boiling water and a french press made better coffee. IMHO the inverter was a total waste of $$$$$$.

 

[sailme88]

Just in case some don't know the formula:
Watts/volts= amps
Watts /amp= volts
Amps X volts= Watts
1500w hair dryer in a 120v wall outlet draws 12.5 amps and would normally be fed by a 15 amp breaker.
a marine microwave oven is already rated for watts, usually around 700. So a 1000 watt inverter would work. But, remember consumption without replenishment can draw you down to a point below where you might under volt and thus under amp and by extension under watt. This can take out the magnetron in a microwave, or motors and pumps not initially designed to run on inverted power.

 

[NotCook]

Since we converted our 120V Grunert refrigeration to 12V SeaFrost, we haven't started our generator in months. So, when we DO need 120V, we use the inverter. We also have a Xantrex, and we use it for such things as the Microwave, lots of power tools (grinder, drills, heatgun, hotknife for cutting lines), and for the little shopvac. Oh, and the soldering iron. I've also used it for the 120V submersible pump when bailing large amounts of rainwater from the dink from time to time. Yes, many of these items could be replaced with cordless equivalents, and we have several saws, drills, impact drivers, sanders, etc., but we also have those other tools. The inverter comes in handy on the hook or mooring.

We had no need for an inverter on our boat until I bought a Torqeedo outboard for the dingy.

We are talking about getting a Torqeedo for the dink, also.

 

[Maine Sail]

@Maine Sail I noticed you are very guarded on the subject of both chargers and inverters I don't see any write up's on your How To site, is the reason related to liability?

There is an article on chargers.
https://marinehowto.com/installing-a-marine-battery-charger/

I have not had a chance to write one on inverters but, it is on the list.... The reason I am cautions is simple, safety. A marine inverter passing UL-458 + Marine Supplement SA (or the equivalent European standards (EN,IEC)), has been tested to marine safety standards and we know that AC/DC isolation, leakage current etc. meets those standards. For example components inside an IP rated marine inverter need to be able to withstand 302F and still pass the ignition protection requirement. This means using top quality components not cheap junk. Internal wiring needs to be stranded conductor etc., etc..

There are far too many issues related to inverters to discuss here but the biggest issue, by far, is proper & safe neutral / ground bonding. Many "portable" inverters have neutral & ground bonded internally. When a DIY installs and inverter like this, and attempts to wire into the vessels existing AC system, you have now created a dangerous on-board neutral / ground/Earth bond 100% of the time.

A marine inverter will have a transfer switch that creates the neutral / ground bond only when the inverter is the source of power and also automatically break this bond when it is no longer the source of power. Even this transfer switch has to meet specific testing requirements so as not to trip or interfere with GFI protection.

With the recent NEC/NFPA regulations for GFI on docks, non-marine inverter installations, or incorrect inverter installations have become the #1 cause of GFI trips we see. This is because the owner or non marine electrician has created a dangerous neutral/ground bond on-board the vessel. It also happens with generator installations.

I have looked up ABYC wiring rules #E-11, A-20 and A-25, but sure would be great to have your insight and recommendations.

It is very simple, stick with only marine UL (or equivalent testing) inverters and have it installed by someone who actually knows what they are doing. Over 90% of the inverter installations we see are not correctly or safely installed. The new land based codes are quickly exposing these poor installations as marinas come into compliance with the current shore based requirements..

Incidentally, after reading the code sections I believe that our boats manufacturer did not follow these rules to the letter, or the rules post date the installation. For instance grounding cable size, grounding both AC and DC all the way back to the shore power iso transformers neutral.
Which means I have yet discovered another project......
Mark

Not uncommon. I have yet to set foot on any boat that meets the ABYC standards 100%. Items that can kill are obviously the most important, hence my caution on AC inverters.

 

[JamesG161]

A marine inverter will have a transfer switch that creates the neutral / ground bond only when the inverter is the source of power and also automatically break this bond when it is no longer the source of power. Even this transfer switch has to meet specific testing requirements so as not to trip or interfere with GFI protection.

That is a KEY safety factor. You pointed this out to me in another post.
That very fast transfer switch is needed.
Jim...

PS: I now leave my Invert mode OFF until needed.

 

[DayDreamer41]

@Maine Sail, thanks for the link and for the words of wisdom it is greatly appreciated, I did find an article you wrote on chargers linked to Sterling Pro Charge Ultra at the Sterling web site last evening.
I spent the entire day yesterday reading manuals for marine or alleged marine chargers and after many hours I found only (1) charger which allows for custom settings, I have read your advice on the importance of not falling out of absorption to early and the effects it has on battery's when not achieving a full SOC. Sulfates forming on the plates, stratification of the electrolytes resulting in early battery demise.
Seems that Sterling is the only charger I could find that actually has a user configurable program so one can make adjustments to the actual absorption charging stage to allow the batteries to come closer to that full SOC, all others that I researched had some limited programming allowing for the user to input the bank size in Ah's but even then the charger would trigger to, "Float" when the current reached a predetermined value, typically 80% SOC. As we know the last 20% of battery charging is the most difficult to achieve and remaining in the Absorption phase of the charging cycle longer will get closer to the grail of battery charging objective.
The sizing determination for a charger is recommended at 10% of the banks capacity plus the expected DC loads imparted on the bank while charging, this rule of thumb provides for not necessarily the shortest charge cycle but rather a reasonable compromise related to time and battery life cycle.
With all that being said I sure wish that Sterling had a 80 or 100 amp charger, but alas the 60 A charger appears to be able to live up to the task, it will just take a bit longer.
I say this as the expected hourly load on our bank while on the hook is approximately 5 Ah's leaving 55 Amps for charging with a 675 Ah bank depleted to 50% it would take 6 hrs at this charge rate to replenish the bank to 100% SOC while at 80 Amps output, 75 Amps available, the time would be reduced to 4.5 hours a bit more reasonable.
The question I have, Is there any other user programmable chargers out there? I know there other good ones such as, Mastervolt, Victron, ProMariner but they don't seem to offer the same adjustability that Sterling offers.

PS - I guess that this post has kinda inverted to chargers.......

 

[Gunni]

Seems that Sterling is the only charger I could find that actually has a user configurable program so one can make adjustments to the actual absorption charging stage to allow the batteries to come closer to that full SOC, all others that I researched had some limited programming allowing for the user to input the bank size in Ah's but even then the charger would trigger to, "Float" when the current reached a predetermined value, typically 80% SOC.

Mastervolt chargers allow for this. You need software and a computer to do so. However, I would never monkey with it.

 

[Maine Sail]

I sure wish that Sterling had a 80 or 100 amp charger, but alas the 60 A charger appears to be able to live up to the task, it will just take a bit longer.

The reason for this is actually quite simple. Above about 60A power supplies become very costly, thus a stand-alone battery charger gets quite expensive above about 60A and becomes less expensive to simply buy an inverter / charger or two 60A chargers. Two 60A chargers leaves you with redundancy where an inverter/charger leaves you with both sides dead should it fail.

I say this as the expected hourly load on our bank while on the hook is approximately 5 Ah's leaving 55 Amps for charging with a 675 Ah bank depleted to 50% it would take 6 hrs at this charge rate to replenish the bank to 100% SOC while at 80 Amps output, 75 Amps available, the time would be reduced to 4.5 hours a bit more reasonable.

It is not just about amperage. The charge acceptance and Coulombic efficiency of the bank defines how long it will take to get back to 100% SOC. Even the fastest charging AGM batteries take 5.5 hours at a .4C charge rate or 270A on a 675Ah bank to reach 100% SOC. Don't count on IC engines getting you to 100% SOC unless you motor for long hours.

To speed through bulk charging simply run both the alternator and genset powered charger then shut down the engine when accepted current drops to 60A.

The question I have, Is there any other user programmable chargers out there? I know there other good ones such as, Mastervolt, Victron, ProMariner but they don't seem to offer the same adjustability that Sterling offers.

Not in the sub $500.00 range. The Victron Phoenix chargers are good but a 50A model will run you about $650.00 and requires a computer and DOS type programming for custom settings. At $650.00 for 50A I would be tempted to move to an inverter/charger.. The Victron's are chargers but represent a 50% markup over the Sterling amps to amps, and more cumbersome to program.

 

[DayDreamer41]

@Maine Sail is one able to run (2) chargers in parallel?

 

[Maine Sail]

@Maine Sail is one able to run (2) chargers in parallel?

Yes, it is done all the time.... On many cruising boats we have wind, solar, alternator, hydro, fuel cell, genset etc. all charging the same bank. During bulk all sources contribute the maximum current they can. Once you reach the absorption voltage limit the charger with the highest absorption voltage takes over to finish absorption charging.