Portable Generator

[Sumner]

It's safe to charge multiple deep cycle batteries in parallel even if they're different ages and types..............A deep cycle battery should last about six years in routine use.

I cut most of the quote out to save space, but good info there for all of us. When our present batteries are shot in the Mac we are going to replace them with 2 deep cycle 6 volt batteries in series and the wiring will then be simplified and we will have a better set of batteries than we do now for all of the reasons that were given. Our outboard is electric start, but can pretty easily be pull started. Not real sure what I would do with a 60-90 HP outboard. I'd probably add one of those starter battery packs or as small a 12 volt battery that would work with a combiner or put one of the low battery monitors/switches that would disconnect the batteries if I worried about leaving something on before going to bed and worried that I might drain them at some point.

question for sumner?? how has that little honda GC160 performed for you on your genset ?. i have one mounted to a little air compressor and two 50' hoses attached to dive regulators that we snorkle with in shallow water less than 30', ours seems to be indestructable.sorry to hijack but this has been discussed to death.

So far it has been a great little engine. I was going to go with something a little cheaper from HF or some place, but after reading on one of the alternative energy sites....

http://homepower.com/files/webextras/mark8.pdf

...how long the Honda's run I thought the cheap ones weren't a wise decission. So far it almost always starts on the first pull and once started I throw the switch that kicks the alternator in and it runs it easy at reduced throttle. It isn't that loud, but louder, as you probably know, than a Honda gen-set. To help that I made a second muffler that attaches to the first. I'll post pictures sometime if anyone is interested and the pipe to ....



http://purplesagetradingpost.com/sumner ... de-14.html

...down near the water gets rid of the fumes and helps lower the noise also. The problem is not the exhaust noise, but vibration noise through the hull of the boat especially if you are down in the cabin. I want to work on the mounts and see if I can get rid of that. If you are not in the boat and 50 feet or more from it you just can't hardly hear it running at all. Working on the mounting isn't a high priority now as we don't run it for days at a time with the ...



http://purplesagetradingpost.com/sumner ... de-33.html

...200 watts of solar we now have.

We bought a Honda 2000 to have on the Endeavour and for other uses as there is room on that boat for one and I didn't want to move the gen-set on the Mac on and off. Since everything on the Mac, and for that matter the Endeavour, is 12 volt the gen-set we made for the Mac is a great addition as it is always mounted, charges the batteries faster than most 110 chargers and is ready to go all the time and is mounted out of the way. We don't mind the looks of it with the cover on and for us making the boat a better cruising boat is our top priority and mods in that direction win out over looks or anything else,

Sum

Our Endeavour 37

Our Trips to Utah, Idaho, Canada, Florida

Our MacGregor S Pages

Mac-Venture Links

[kevinnem]

There was a post on the last page that commented that the "circuit was blown because it was open, and no battery attached". If the it was OC (open circuit), then the resistance would be infinite, and current would be 0. There is no electricity/power flowing in a O.C.. The wiring in my house isn't blown because I have nothing plugged in to the walls. Can we provide some better explanation for this, and what might be the issue? I don't seem to understand the risk/concern.

[robbarnes1965]

Hey Sumner,

I don't know why I never thought to click on the Endeavour 37 link before. Nice Boat! I am anxious to see what your "MacGyver" skills create

Rob

[kevinnem]

This might be an ok gen, but I would look at the specs a little more. From the mfgr's site:
http://championpowerequipment.com/doc/C ... 0Paper.pdf

Noise levels:
% of Full Load ....Noise Level (dBA)
0...............................53
25.............................54
50.............................59
75.............................65
100...........................65

The Honda 2000 is 53-59 db (1/4 load & Rated load). If noise isn't too much of a factor, then no big deal. But at 75% there is a 6 to 8 db difference. That is a lot.

I have 2 Honda 2000s. In Champion's case, they say it is dBA, with the "A" indicating that they are showing the dB increase over Ambient, or normal background noise. They define "A" as 45 dB.

If they are using 45 dB as their reference, then their 100% load figure of 65 dBA is very loud. 45 dB + 65 dB = 110 dB.

~Rich

I have to agree a bit with Rich, that it seems there is some confusion to how the deciBel system works.
I would first like to say that I can not find there definition of "A" stated above (can't find manual), however in the world of sound there are 2 commonly used ratings "A" and "C". Why? Well it turns out human hearing is not very "flat" some sounds are precieved as louder then other, even though they have the same amount of energy to them. To make matters even more complex, this is not a consistance curve, it changes with how loud the source is. (AKA the treble/bass ratio changes with the volume knob!).

The "C" rating is basically flat, though not perfectly. "A" will filter out (mostly) the low frequency sounds. For "quite" sound A is usually used because at low volume we can't here low frequency anyway (IE the "A" weighting matches our low-level hearing" the best). You can Google the flecter-munson curves for more details. There can be a HUGE! difference between A and C weighting if the source being measured has lots of low frequency information.

Also, adding dB is not as easy as adding the numbers, because DeciBel is a logarithmic scale. When compare 2 sounds that are vastly different in volume, the Total volume is that of the loudest sound. The most addition you get is 2 identical sounds, and in that case , you get an increase of 3 db. So if 1 generator is say, 50 dB, and you place another beside it you get 53dB if you place yet 2 more (total of 4 generators) in the same place you then get 3 dB more, total of 56 dB. and so on (you get 3 dB more each time you double the number of generators). In reality you will not get a full 3 dB - more likely about 2 - why? Because the 3 Db assumes that the 2 sources are EXACTLY the same volume, - make EXACTLY the same sound, however ti doesn't assume that they add in a perfectly coherent/synchronised way. In reality a lot of the sound cancels out the sound of the other, resulting in less then 3 dB. Sometimes this is intentionally don't in head phones or other place - you MAKE the sound out of sync with the area around it and get a "notice cancelling effect".

Lastly , from an accounting prospective I would mention that placement is important for noise measurements. Some thing in "free air" AKA hanging off a crane is said to be in full space. If you place it one the ground you will have a 3 dB increase in volume - if you place on a wall you get a further 3dB, if you place it in a corner (2 walls, and ground) you get another 3 dB ..... so at the end of the day a generator in a corner will be 9 dB louder then one in the "open air". This is substantial! This effect can also be used for good. Because if you have a sub-speaker, say for a computer, and you need more volume out of it, you can get 10dB more volume out of it, by just placing it in a corner of the room! meaning your 50 watt sub, now has the same output as a 500watt sub!!!


Cheers. TTYL

[bartmac]

The failure of the charging coil in our outboard is down to it not able to handle full output continuous....the battery bank ie 2 start batteries at approx 100 Ah and 2 gel batteries at 186 Ah each....Suzuki claim the normal duty is a replacement of the power required to start the motor ie a few hundred amp for a few seconds ie very little BUT in our case we have a 12V fridge running of our gel batteries at 4.5-5 amp with probably a 33% duty cycle which in a 24 hour period adds up......other loads such as lights,stereo,computor,GPS,autopilot,12v evaporative cooler,waterpump,compost toilet vent 24hr.So the reg in our outboard "saw" a voltage which allowed it to go 100% for hours on end and cooked.We have a DC-DC charger which can charge from our start batteries BUT at 20 amps will cause the same problem because it exceeds our outboard's output SO we end up with it cooking anyway.We do have about 180 watts of solar panel but due to shading,angling etc thier output has never exceeded about 8 amps on the meter so with an effective 4.5-5 hour rating adds up to a max input of 40 amp or so?

[Crikey]

Hey Bart, any directed energy weapons in that lineup!

[bartmac]

We've always planned to stay on our 26X for a number of days at atime at least (travel distance from water )....so whilst the list of what we regard as necessary may be a bit long , it just makes life more comfy(happy wife happy life)....so we elected to set up an electrical system able to handle all....we still had frozen food after 14 days away recently.....now about the energy device......just bought a slingshot will that do...not electrical but damn effective against jetskiers,wakeboats etc

[Crikey]

My preference for stinkpotters is a potato canon at twenty five meters.

[seahouse]

Hey Bartmac--

Trade that singshot in for this....http://www.youtube.com/watch?v=ShEUfJt-xhM

and no one will bother you.

-Brian.

[seahouse]

Hey Kevin --

There was a post on the last page that commented that the "circuit was blown because it was open, and no battery attached". If the it was OC (open circuit), then the resistance would be infinite, and current would be 0. There is no electricity/power flowing in a O.C.. The wiring in my house isn't blown because I have nothing plugged in to the walls. Can we provide some better explanation for this, and what might be the issue? I don't seem to understand the risk/concern.

A good question. Simple house wiring is constructed somewhat differently than complex charging circuits. There are generating circuits which require a load across them to prevent damage.

A windmill, for example, will destroy its internal circuitry if the output wires are not either connected to a load, or shorted to each other. While it is quite true that the current is low, or zero, excessively high voltage results from an open circuit. Protective circuits exist but are sometimes not included, and the frequency of the occurrence is low.

Using house wiring as the example, the voltage (open circuit) across a 120V outlet drops to about 12V when you connect, say, a kettle to it, and returns to 120V again when you unplug it (check it and see for yourself if you aren’t already aware of this). That’s all fine, because the circuit is designed to handle the 120V. Albeit at lower amperage.

Now picture the same scenario, except the circuit is designed to handle only 12V instead (with the kettle load assumed to be a permanent part of it of course). Disconnect the kettle, and now the open circuit potential difference jumps to 120V!

Just like in the charging circuit, the voltage jumps to excessive levels that are higher than what it was designed for, and damage can result.

It is not unreasonable to conclude, although I have no personal experience with such an occurrence myself, that some outboard motor alternator charging circuits could be damaged by an open circuit condition as well.

- Brian.

[seahouse]

Hey Mastreb –

I think the point is not whether or not it is “safe” to charge (mismatched) batteries in parallel, but whether it is in the best interest of battery longevity to do so.

While deep cycle batteries will withstand more abuse than starting batteries (through either inaccurate charging profiles, or excessive discharging) the data-backed wisdom is unanimous in the industry that it is not good for battery life to do so.

Using a “smart charger” to continuously monitor and control the rate of charge of an individual battery will charge it faster, more efficiently, with less heat buildup, and give greater life, compared to simply allowing the battery’s rudimentary internal “push back” resistance to dictate it.

I have first-hand experience with a parallel-charged 4 deep cycle battery bank that went bad (and all 4 were replaced free under warrantee by the seller, $550) in less than a year, in a solar/wind bank, because the batteries were not of consecutive serial numbers, and therefore mismatched. The replacement batteries (consecutive serial numbers) are now well into their third year without issue.

They were replaced because it is also accepted in the industry that parallel-charged batteries must be closely matched to each other. They paid for the replacements because the were made aware that they made a mistake by selling 4 batteries that were not.

You will be hard-pressed to find any battery manufacturer, deep-cycle or other, that will recommend fully discharging a battery, with any regularity, if at all. I've never seen or heard of it. Most data suggests staying above 50% discharge depth (which is at around 12V), as often as possible, although that is recognized as not always practical.

Au contraire on some other technical points, I do think the above bore repeating, but as has been mentioned, more details of the facts are the content of previous threads, so I as well see no need to rehash them over again.

- Brian.

[Catigale]

It's still not clear to me if the alternator failure referenced above was due to overload or prolonged use at full rated output or a failure from disconnecting the alternator from the 12 vdc during use.

The latter is a well known limitation of most types of alternators including automotive ones. On a boat, we have the ability to mistakenly disconnect the battery while the engine is running by umisuse of the Perko type switch.....1-2-OFF

[mastreb]

Hey Brian,

Sure, a charge controller is going to reduce heat generation considerably and increase longevity somewhat. But consider that they didn't even exist until the mid 1980's, and lead-acid batteries predate them by over 100 years.

Charge controllers are sophisticated electronic devices that are also somewhat prone to failure, especially in marine environments, and they're not cheap. I question whether the perhaps 25% extra longevity gained by a deep cycle is would even come close to paying for the charge controller especially considering that it's not gong to last ten years, which the life span of just two batteries. Spending even just $100 (the cheapest real charge controller I could find--harbor freight) on a charge controller to make an $85 battery last six years instead of four isn't really cost effective in my mind. It would have to last 20 years to pay for itself, and it's not going to do that.

I prefer to keep my boat as electrically simple as possible to avoid failures. Deep-cycle batteries can be routinely drained down to 20% safely--the 50% you quote is the safe limit for starter batteries.

I certainly understand the impetus to do things the best way possible, but charge controllers for lead acid batteries are one of those cases where the total cost just doesn't justify it in my opinion.

Charging from PV requires a charge controller because the open-circuit voltage from solar must have a regulator in front of it to avoid overvoltage problems. But engine alternators have voltage regulators that prevent overvoltage and make charge controllers optional.

Matt

[seahouse]

Hey Matt!

There has been considerable research done on this topic and most of the data is available online to anyone who cares to be aware of it. The following link gives what I consider to be a good fact-based overview of what have been accepted general practices within the industry that to my knowledge are not in dispute. It conforms both with what I have read elsewhere and with my own experiences and observations.

I hope it clears up some of the misconceptions on this thread and others on the topic.

http://www.windsun.com/Batteries/Battery_FAQ.htm

The following is excerpted from it in reference to deep cycle batteries…

"Battery life is directly related to how deep the battery is cycled each time. If a battery is discharged to 50% every day, it will last about twice as long as if it is cycled to 80% DOD. If cycled only 10% DOD, it will last about 5 times as long as one cycled to 50%. Obviously, there are some practical limitations on this - you don't usually want to have a 5 ton pile of batteries sitting there just to reduce the DOD. The most practical number to use is 50% DOD on a regular basis. This does NOT mean you cannot go to 80% once in a while. It's just that when designing a system when you have some idea of the loads, you should figure on an average DOD of around 50% for the best storage vs cost factor."

- Brian. note: DOD above = depth of discharge

[flyboy26m]

Well, not happy to hear that as I thought it was USA made. I know I can get service for it here.

As far as quality, I have used it for two years and have no complaints. So far it has run everything I have hooked up to it.

flyboy26m wrote:

I purchased a similar unit called a Generac from Cabellas for about the same money on sale. The unit is made in Wi-USA.

Generac is located in Waukesha, WI, but their small portable generator is imported from China.

I was also considering purchasing that generator but its price was too reasonable for a "Made In USA' product. Being of a suspicious nature, I called Generac direct and was told that it is made in China. I try to stay away from Chinese products and purchased the Yamaha EF2000iS instead. I am a firm believer in "You Get What You Pay For" and also "If It Looks Too Good To Be True, It Probably Is."