LINK 10?? Worth the bucks?

[paj637]

To KM,
I apologize if my attempt at sarcastic humor offended you. I have been on this forum for several months and have always read your posts closely and very much appreciate your words of wisdom.
sincerely,
PAJ

To all others, my auto start generator and ABT remark wasn't meant to be taken seriously. Just a little bit of misdirected engineering sparring. Again, I really appreciate this forum and having the opportunity to read so much good information on the wide variety of topics. I have learned alot from all of you.

[kmclemore]

Thanks for that, PAJ.

And a very personal thanks to DLT, Frank, Mike and G for helping to clarify things. You're wonderful guys.

PAJ, I'm no expert - indeed, I'm far from it. However, like most of the other nice guys and gals here, I'm simply doing my best to help others where I can, in the best way I can, given my many limitations. I live with the simple belief that one should live one's life in service to others - as with the Scouting you mentioned and my many other volunteer involvements - and for me this leads to great satisfaction and inner peace.

[walt]

I think the Link 20 is a cool instrument but I also dont think its for everyone. My main reason for not using it is that it burns up 90ma (170ma with the bright display) continuously and you have to keep it on at all times if you want to know how much amp hours its used. I really dont want or need a high power system for my application. Some people do, some people dont.

A couple other things to note about it..

The equations (Peukert) dont apear to take into account temperature. They do take into account current which is likely the most important. I dont have a reference to give but use but my experience with a solar system in a mountain cabin is there is also a fairly large temperature dependence in how much capacity a battery has. Maybe they just dont show the temperature depence in the equasion in the manual since the temperature reading is available in the box.

Second, the box does have temperature sensing but it apears to be inside the box itself. If you mount the batteries in a place which sees a different temperature (and the batteries can create there own temp rise), some of the results could be in error. A 10F temperature difference is .2 volts difference in battery voltage. Some more sophisticated charge controllers for solar systems will have a temperature sensor which basically is bolted on to the battery lug so that the exact temperature of the battery is monitored.

I think it would be cool to have but I get by on my past experience looking at voltage only just fine. But, I find it hard to argue with just about anything Kmclemore has to say..

[walt]

Hmm.. there is a sleep mode that only consumes 25 ma ( about 1/3 watt) which is more reasonable (even for a power tight wad like myself..). I woud guess that in sleep mode, all monitoring is still going on, just no display.

Also, in the hookup as described, you can still have solar panels supplying some of your load current and the monitoring of the battery charge would still be accurate (hookup shows the only thing being connected to the battery ground lugs is the current shunt sensor. The solar charging system ground would be hooked up to the system ground).

[kmclemore]

Hi, Walt.... thanks for the kudo's but you overstate - electronics is definitely my short suit. (sorry.. bad pun)

However, I did want to correct one thing - the Link 20 does compensate for temperature, albiet not automatically as far as I know. You can set the ambient temerature manually (in 10ºF increments), or just leave it with the default temp of 70º F. Now, my batteries are located low and forward in the boat, so they tend to stay pretty cool, which of course is best for optimal charge & discharge.

The Link 20 goes into sleep mode fairly quickly, so I suppose most of the time we're running at 25mA... not bad for what you're getting. It does a great job of letting us know the % remaining, which of course is the critical measure. When it's in sleep mode you can still see the horizontal bars showing the level remaining in each of the two batteries.

Hey, what can I say, it beats using a hydrometer, a thermometer and a calculator, which was what I had been using previously!

One other note - the Link 20 has an 'alternative energy mode' wherein the first meter (Batt 1) will show the actual battery condition, and the second meter (Batt 2) will show cumulative input received from the charging source (like a solar bank, wind generator, etc.). I haven't used it in this mode yet - although I do have a 40W solar cell on my slider - but it sounds pretty cool.

[richandlori]

HEA84201601
HEART LINK 10 BATTERY MONITOR
Price: $195

It was the absolute best $195 I have spent on electronics.

[walt]

Well, Im still at the electronics level on my boat where the "best" thing I bought was a nice stereo with a direct IPOD link..

Off topic but related - For people with solar panels and who like cool things, I think these charge controllers are cool: http://www.blueskyenergyinc.com/solarboostreview.htm

I have a 160 watt panel (not on the boat) and with the MPPT contoller and when the panels are pointed at the sun, I have gotten close to the full 160 watts out of them. The MPPT controller is more expensive than a non MPPT controller and for lower power systems where you have plenty of area to mount panels, it might be a wash cost wise of either adding more panel area or going to the MPPT contoller.

However, on a boat where you have limited area for panels, I think the MPPT controller gets interesting. Unfortanetly the one I bought is major overkill for the boat and I dont know if the company has come out with a lower power one - or how they would do in a marine environment. But if they do, Id probably buy one. They also have a fairly strong patent on this idea whch unfortanately has probably limited the general use.

One other reason to consider solar on a boat.. If you have shore power and lots of time to charge, this wont matter. But if your charging real time either using a generator, altermator or even a AC charger, you can get to 85% charge fairly quickly but the last 15% takes forever (and inefficeint if your using something which is capable of putting out lots of current but you cant use it). Just like not taking charge from the batteries under 50%, charging to 100% makes batteries last longer. If you have plenty of time where the boat is not being used, the solar panel nicely charges the batteries up to 100% (which in some cases will give an extra 15% capacity and make the batteries last longer).

Dont the current monitors require a 100% charge in order to reset and calibrate (and be accurate)? Ill have to read the manual in more detail..

[Frank C]

... Off topic but related - For people with solar panels and who like cool things, I think these charge controllers are cool:

http://www.blueskyenergyinc.com/solarboostreview.htm

That's a great link, very interesting techno-description, very interesting product!

The "MPPT controller" seems overkill for a weekender Mac, but it's possibly mandatory for longer-term cruising, or on a bigger boat kept on a mooring (i.e. richnlori's ThirdDay). I don't even have a solar panel, but if I was spending much time on the hook (or permanently moored), I'd sure consider pairing that Controller with my solar array. But for just a Mac anchoring-out on a week-long cruise, the price of these two items together, (the PV array & MPPT controller) is d@mned near the cost of Honda's 1kw genset .... hmmm.

Regardless ... the Link Monitor seems to me as mandatory, even for just weekend cruising. My Suzuki 60 (25 amps) can always make-up any deficiency but it's very nice to know the "real DC reserves."


Edited to clarify intent re MPPT Controller versus Link Monitors.

[Duane Dunn, Allegro]

I suppose that depends on how you use your Mac. If it's a weekender to you then all this probably doesn't matter.

My family of 5's longest trip on the Mac is 23 days. We've made a number of week long trips, and evem more 4-5 day trips. Over all we have spent more than half the 93 days we've been out over the last 6 years at anchor or on moorings where there is no shore power. Knowing the battery state on these multi day without a plug trips is important to me and well worth the $200, particularly compared to many other $200 things you can buy for the boat that have much less utility.

[walt]

I guess the other thing to consider is safety and having a motor always avalaible is very important. In my case, if my batteries were extremely low, I could still charge my cell phone or VHF radio. But I dont need the batteries at all to start my 8 hp motor.

I understant that you can pull start a 50hp but its not easy? I dont know how true this is but Id probably be watching my batteriers a lot closer if they were an important part of having the motor available.

[kmclemore]

I understant that you can pull start a 50hp but its not easy? I dont know how true this is but Id probably be watching my batteriers a lot closer if they were an important part of having the motor available.

The answer to that is "it depends". Some 50's have conventional ignition, and with a good hard pull you can get'er going. However, some other 50's use an electronic ignition that requires at least some electrial current before pull-starting the motor.

[Duane Dunn, Allegro]

Yet another reason I'll probably stick with my noisy gas hog Tohatsu 50 for quite a while. I've watched others hand start theirs and it really wasn't hard at all. The only real trick is making sure you have enough clearance around you so you don't smash your hand on part of the boat as you give it a pull.

[Chip Hindes]

The first time I pull started my Tohatsu 50, I put all 225 lbs into it; it started so easily and quickly I nearly fell on my face.

[walt]

Hello Frank,

The MPPT controller that is availble (at least a few years ago) is definately a major overkill for a "smaller" sailboat. The one I have for my non-boat application uses 10 to 20 times more current to "just turn on" than the solar controller Im using in my boat. But.. that still is something like 100 ma vs 5 or 10ma. The MPPT I have is rated to 25 amps.

Im pretty sure they could make a lower power one which worked nicely for a smaller solar application (like a sailboat) but for some reason they dont - maybe no market except for me?

The MPPT controllers also tend to work better in sunny cool climates (like Colorado) which is also where Im using mine. If someone didnt want to read all the stuff in the link, here is the readers digest version of what they do. Basically solar panels are current output devices and they are designed to have a DC voltage always higher than what the load needs. So if you have a panel that is rated at 2.3 amps at 17 volts (ie, 40 watts), when you connect it directly to a battery (which most controllers do with a P channel FET switch), the panel still puts out 2.3 amps but now at the battery voltage of say 12.5 volts. So the actual power delivered to the battery is 28.74 watts (2.3*12.5). If you took the same panel and used it on a six volt battery, the panel would work just fine and still put out 2.3 amps but now the power would only be 13.8 watts (6*2.3). The MPPT controller lets the panel operate at its maximum voltage and current but oututs to the battery the voltage required for whatever charging state the battery is in. The one I have will show current in from the panel and current out to the battery and often the current out to the battery is 20% higher than the current in from the panel. The 100ma the MPPT controller needs to run is "in the noise" compared to the 20% extra current Im putting into the batteries.

FYI, my 20 watt solar panel and 230 amp hours of batteires is also a major overkill for my normal weekend use. Im planning a five day trip this summer and may supliment my power with an 80 watt solar panel that I already have - but I will only need it if the kids need to run the stereo/dvd player CONSTANTLY (which is a pretty good chance) and I dont want to let the batteries get below 50% - which I also dont have much of a problem letting happen a few times in their lives - Ill "make it up" to the batteries by having them charged to 100% most of the time. The outboard which came with the boat puts out 5 amps charging (if it worked - it doesnt and probably only gets this at WOT - which I never run the motor at), and how much I plan to use the motor, it wouldnt have helped much anyhow. And as a bonus, my solar panel charges the batteries and keeps them at 100% which is not effiecent and takes too long if you have to do this with some gas consuming motor on the boat. But, the whole system is dependent on me actually using the boat a small percent of the time (which is the case).

You might have guessed that I like solar? Dang, I may have to get one of those fancy charge monitors just to see how they work.

[walt]

Thinking about the 1000 watt genset a little,

Seems you could run a electric trolling motor "all day" with one of these (some trolling motors run about 50 amps which is 600 watts). Is an electric trolling motor adequet as a backup to get you home in case the main outboard fails?