Battery Monitoring

megalops · Post by **megalops** » Fri Mar 20, 2009 2:13 pm

OK, I find myself posed with a chance for new start.

On my 36' Gulfstar trawler (insert nasty powerboater slurs here) I have recently, with the help of the forum, converted my battery setup. I now have 4 6V deep cell interstates (232 AH ea.) wired in series parallel to form a house bank and 1 4d as a cranking battery that serves both motors. They are combined through a blue seas switch (forget the model) and an acr.

They are charged by 2 basic AC delco alternators and a xantrex truecharge 40 which can run from shorepower or the genset. I don't seem to have problems keeping my batteries at acceptable levels.

None of my 4 ammeters (2 ea. flybridge and LH) works. During my instalation of the new house bank I somehow shorted out the analog voltmeter on my panel and now it doesn't work either.

I've never worried much about the ammeters, my tachs pick up off of my alternators so I can tell if the alternator is working if my tachs work.

I'm considering replacing the whole deal with a single link 20 monitor.

What do you guys think?

Thanks

David · Post by **David** » Fri Mar 20, 2009 3:22 pm

I've used a Link 2000 for about 15 years now. They are highly accurate and reliable.

Maine Sail · Post by **Maine Sail** » Fri Mar 20, 2009 5:55 pm

I really don't think you'll need to monitor the start bank.

I would consider the Victron line of battery monitors. They were the actual makers of the Xantrex XBM. I have owned a number of Link products and currently use the XBM by Xantrex (really by Victron) and by a long shot the XBM has been less buggy and more reliable than my Links were.

The Victron is also the absolute easiest battery monitor to hook up. It uses a single Cat 5 type cable from the shunt to the meter and literally takes no skill to install. They make a BVM 600 and BVM 602 (two banks). Hamilton Marine should have them in stock soon and Jamestown Distributors already sells them. Oh and they cost less than the Xantrex links do. A BMV-600 for one bank is $199.00 complete at Jamestown Distributors..

Victron BMV-600
http://www.jamestowndistributors.com/us ... ry+Monitor

David · Post by **David** » Fri Mar 20, 2009 6:32 pm

I haven't found the Link 2000 to be buggy at all. It has performed flawlessly since installed in 1995.

Popeye1865 · Post by **Popeye1865** » Fri Mar 20, 2009 8:49 pm

i'm not sure if your charger has a cat 5 output but most of the larger xantrex chargers allow you to plug into a link2000 so you can monitor your bat as well as control your charger/inverter. i don't know if victron has this capability. something you might consider if you plan to buy an inverter/charger in your future. and i do feel that monitoring your start bat is a good idea. it can show you warning signs of issues forming in your charging system or bat life.

Popeye1865 · Post by **Popeye1865** » Fri Mar 20, 2009 8:51 pm

how are your isolating your banks? how are you balancing your alternators?

Maine Sail · Post by **Maine Sail** » Fri Mar 20, 2009 10:04 pm

Popeye1865 wrote: i do feel that monitoring your start bat is a good idea. it can show you warning signs of issues forming in your charging system or bat life.

I suppose if you have two separate charging systems then a dual bank monitor is a good choice. If you charge both banks via one alternator and only ever start you motor off the start bank all you'll really see is that your starter rarely even draws 1 amp hour at best. To start my 44hp diesel it does not even register .1 ah on my battery meter. I think Popeye is right that we need more info on your charging system. Are both alts parallel or dedicated one to each bank?

It's entirely up to you & how your system is laid out but I have stopped monitoring my start bank, except for voltage, which I have displayed via a bank 1 or 2 dip switch. Start banks don't see much use or abuse and more often than not they reside at a 98% to 100% rate of charge.

Of course the OP is starting big power boat engines so he actually may see an amp hour or two of draw on the banks when starting as opposed to my .1 amp hour..

Maine Sail · Post by **Maine Sail** » Fri Mar 20, 2009 10:14 pm

David wrote:I haven't found the Link 2000 to be buggy at all. It has performed flawlessly since installed in 1995.

My link 20 stopped calculating percent of charge at the two year mark. Xantrex had no answers as to why and it was out of warranty so I never did get an answer.

I have a dead link 10 sitting in my barn, well not totally dead it still tells volts, that quit at the five year mark. I have not had good luck with them but many have. My XBM on the other hand has been performing flawlessly but of course Xantrex no longer makes or private labels this unit...

megalops · Post by **megalops** » Sat Mar 21, 2009 1:15 am

Both of my alts go to the starter batt. I rely on the acr to send the amps to the bank that needs it.

My engines are small, perkins 4-236, 85 hp ea. They turn over quick and easy. I could probably start both of them with a group 31, but like to have the extra capacity of the 4d.

In fact, my 36 year old us built Trawler has a lot more in common with most of the boats on this forum than it does with modern powerboats. That's why I'm here.

I'm not real worried about monitoring my start bank. But we do stay on the hook for days at a time, so I'd like to be able to keep a better eye on my house bank.

megalops · Post by **megalops** » Sat Mar 21, 2009 1:24 am

popeye,

Both starter cables run from the engines to a single lug, then a 3/0 cable runs from the lug to the starter battery.

The house bank goes direct to the panel.

An ACR connects the to banks. Or I can set the batt switch to combine.

Ceasar Choppy · Post by **Ceasar Choppy** » Sat Mar 21, 2009 8:52 am

+1 for the XBM. I too had a Link 20 at one time that was buggy. I ditched it for the XBM and it easier to read and hook up. If you are that concerned about your start battery, get two XBMs! One for each bank and no room for confusion.

Popeye1865 · Post by **Popeye1865** » Sat Mar 21, 2009 7:44 pm

well these questions always open up a myriad of follow up questions. the biggest is how you use your boat. eng run time, amp hour usage, price, future plans, the list goes on. if you run the engines a lot/plug into shore power and use little power you need smaller alternators and smaller bat capacity. but as you plan to extend your time without the engines running or your batt usage you will need higher capacity alt or larger bat bank or both.

more questions for you.
when you say you have no problem keeping your bat charged, how do you know? what is the voltage 12v is roughly 50% discharge (the point at which most bat manufactures recommend you recharge).

Do you have future plans to upgrade to larger charger/inverter?

as you have your boat setup now, both alternators feed your start bank and then when your start bank is up to voltage your combiner kicks on and starts to charge your house bank. you may want to think about getting a unit to balance your alt output between your two alt. currently you may find that one alt is doing all the work and the other is charging very little.

ultimately all of this is complicating the issue. you need to determine how you plan to use your boat now and in the future and make your decision based on that. xbm is simple and work well link 2000 will allow you to monitor more parameters as well as charge/invert (nice if your going that route.

megalops · Post by **megalops** » Sat Mar 21, 2009 9:55 pm

Thanks for your reply popeye. I'm aware of the holisitc questions that my seemingly simple post brings up. Batteries and their charging/maintenence are almost like the anchor question it seems.

My boat and its usage falls somewhere in between the two camps: cruising sailboat and typical powerboat, which I would define like this:

Cruising sailboat-runs his engine a few hours or less while underway, prefers to rely on his sails. Stays on the hook for long periods of time, sometimes weeks. Charges his high capacity house bank through solar, wind, or by running his main engine at fast idle (not good for your engine btw). Small engine sometimes creates issues when user tries to get a very high output alternator on a low hp engine. Relies almost exclusivly on dc power.

Typical powerboat. Runs his engine (s) all the time while underway. Big, powerful engines can run pretty much any alternator. Most anchor out very seldom, instead going from dock to dock. many run the genset any time the engines are running or any time they are not plugged in. This allows them to rely on ac power for most things. Often have smaller house banks. If the genset dies or if they are away from a marina (not likely) they are in a world of trouble.

Me: I run my engines anytime I am underway. I run the genset only when needed (it is loud and smelly) We anchor out a lot, but not exclusively. On a typical month cruise we may spend 10 nights at a dock.
We need ac power for hot water (I'm going to change this soon), and air conditioning (we only use it occasionaly, but it gets hot in FL in the summer). We seldom spend more than 2 nights in one spot. I run the genset for an hour or two each day, it is nice for making coffee, using the AC side of the stove, heating the water tanks etc. In the past this did a decent job of keeping the house bank up as best as I could tell. My cheap old 2 8d house bank lasted 3.5 years.

I had a analog voltmeter and a voltmeter as part of my gps.

When we aren't using the boat, which is most of the time unfortunatly, it sits at the dock, plugged in to 30A, with the charger running.

So you see I'm some sort of weird hybrid between the two camps.

I really don't have the funds right now to change my whole system. I just want to find a reasonably cheap way to monitor my house bank.

It takes very little time for my alts to top off the starting batt.

Good point about not knowing which alt is doing the work. I'm in the dark about that.

JonnyBoats · Post by **JonnyBoats** » Sun Mar 22, 2009 5:19 pm

Ample Power has posted some very good information on batteries with their Ample Power Primer at http://www.amplepower.com/primer/index.html

Popeye1865 · Post by **Popeye1865** » Sun Mar 22, 2009 8:29 pm

I'm a mechanic at a yard that works on mostly swans money is usually not the issue i try to build systems that are simple and user friendly. batteries are one of those things people who don't know get very confused. if it were my boat i would be shooting for a system that allowed me to monitor as much as possible so when something is starting to go wrong i will know before it becomes a real problem. but more often than not these systems that allow you to monitor many aspects cause issues (almost always user created)

it sounds like your planning on keeping most of your current setup so i would recommend a xbm or victron. i believe xantrex makes a link pro that allows you to monitor Eng bat voltage only, as well as all parameters for house bank a good halfway point between link20 or link2000 and the victron or xbm.

i know balmar makes a unit they call a centerfielder that levels off the output between two alternators on separate engines but i think you would need externally regulate alternators for that. I've usually found most alternator mfg's to be fairly friendly so it might be worth a call to see if they make anything to balance internally regulated alternators.

i guess i shot myself in the foot even considering asking about anchors o well haha
good luck

megalops · Post by **megalops** » Mon Mar 23, 2009 10:53 am

Oh, I know all about anchors. I've dragged pretty much all of them. :-)

So It Goes · Post by **So It Goes** » Mon Mar 23, 2009 1:42 pm

I've used Ample power battery monitors ( which were great) in the past. The current boat had a Link 10 for the house bank and a Xantrex for the propulsion bank...Neither of which I was very happy with so I replaced them with a TriMetric by Bogart Engineering which is heads and shoulders above anything else I have ever used...and CHEAPER. http://www.bogartengineering.com/

Having electric propulsion makes one very serious about monitoring ones batteries!

JonnyBoats · Post by **JonnyBoats** » Tue Mar 24, 2009 9:53 pm

Having electric propulsion makes one very serious about monitoring ones batteries!

If you have a large dollar investment in batteries (which I assume you do) you want to be particularly careful about the charger you use. With proper care batteries can easily last over ten years. Many people with simple systems are happy to buy new batteries every 2-3 years, which I suppose is OK if you only have a small, single, house battery.

Take a look at http://www.cdtechno.com/custserv/pdf/2131.pdf for a discussion on how ripple current from chargers can negatively impact your batteries.