INSTALLING THE 48 VOLT LITHIUM BATTERY

 One of the nice things about electric propulsion in a sailboat is the ability to upgrade parts of it as new technology comes along. When I made the conversion back in 2008 Lithium batteries were new and available but, were very expensive. Plus there were long wait times for delivery. So I went with the 8A4D AGM batteries. Today the prices have come down as have delivery times. My 48 volt Allied Battery 105 Amp Lithium battery arrived in two days. 

Installed the single 48 Volt Lithium battery on board. It was easy using the Nova Lift I originally installed in 2008 to lift the 120 pound AGM batteries for installation.

The new 48 volt lithium battery replaced almost 500 pounds of AGM lead acid batteries that I have been using since 2008 when I converted to Electric Propulsion.

In addition to the four AGM batteries I was also able to get rid of a lot of other jumpers, tie downs, wires, fuses, screws and battery insulators.

The best part is all maintenance is now done from inside the cabin. No more squeezing down the cockpit hatch and doing boat yoga.

A BATTERY SEA CHANGE

It was in 2008 when I converted BIANKA from having diesel auxilary power to electric propulsion. I had four heavy 8A4D AGM lead acid batteries totaling almost five hundred pounds to power the Thoosa 9000 electric propulsion system.

 

The batteries were located below the cockpit and though while accessible it wasn't really comfortable to work on them. This season they are being replaced by a single 48 volt lithium battery that weighs less than a single one of the old batteries.

Even better I will be able to access the terminals for maintenance from inside the cabin. No more squeezing down through the cockpit hatch is going to be a welcome change.

DEATH OF A WIND GENERATOR

My Primus  (formally Southwest Wind Power) 48 volt wind generator stop working last
year. It had been in operation 365 days a year for the past 8 years so it was probably
due for some refurbishing.  The wind generator has a sophisticated regulator circuit.
Which I imagine had failed. So sending the unit for refurbishing back to factory seemed
like a good investment.
  Unfortunately, I got some bad news along with some photos of the damage: 

“The technician was able to begin working on your unit, unfortunately we found some bad news.  Please see attached pictures. The stator in your turbine overheated which leaks the varnish from the stator throughout the entire turbine.  In these instances, the turbine is not repairable (or not worth repairing due to how much it would cost).”

After discussions with the technicians at the factory I asked how this failure occurred.
He explained that too much wind can cause this type of damage.  Though the
wind generator was advertised as having circuitry that protected it from excessive
winds obviously it failed.
Since the generator was out of warranty I was only offered at discount at purchasing
a new on which was still in the thousand-dollar range.  Even with a new 5-year warranty
the reality was there's no guarantee but the unit would not fail again once the warranty
was up. While I liked having the wind generator as part of a multi energy approach to
charging my electric propulsion battery bank. In the end I thought the cost of a new
generator was not worth it  and the money might better be spent on additional solar
panels. 

TESTING AN ELECTRIC PROPULSION BATTERY BANK

It came time to test the batteries of BIANKA’s electric propulsion bank to make sure  
the suspect battery 1 was indeed bad and the others we're still good. To test the
batteries I first needed to empty out the locker so I could squeeze myself down into
the space.

Once that was done I gathered my tools and tester hoping I didn't forget anything
because working down below is a tight space for big guy like me and getting out of it
is much harder than going into it.
So I try to minimize going in and out of the space. The nice thing about down below
since I took out the diesel and put in electric propulsion is my clothes will remain pretty
clean and I won'tsmell of diesel and oil.

I use the Centech Battery Analyzer tester for quick checks on the batteries.
It tests the internal resistance of the battery and also the cold cranking amps
available.  It's not a load tester but can give you a quick look at the condition of
the battery. I'm particularly interested in battery 1 which seemed to have very
limited capacity when I used it last season.
Time to head down below and begin the testing:

As I suspected battery number one had tested numbers were way out of line
compared to the other three batteries in a 48 volt string.

While the voltage reading  on the battery Look good at 13.11 volts.  The internal
resistance of the battery was very high reading 35.8 milliohms.

Compared this to the next battery in the string which had an internal resistance
of 1.95 milliohms.
Also note at the top of the display screen. The one above has only one pixel
and says NG. While the one picture below pixels all the way across and says
good.

This confirmed my suspicion that there was definitely something wrong with
battery 1. Likewise batteries 3 and 4 had similar internal resistance specs to
those of battery 2 with regards to the internal resistance of the batteries.

Moving on to the  cold cranking amp tests  once again showed that battery
one was a indeed defective. The tester showed that there were only 85 cold
cranking amps available.

The  spec for the 8A4D battery is 1100 cold cranking amps. Tests of the
other three batteries showed  they were all over the 1100 spec for cold
cranking amps.

I tabulated the results and  and entered them into BIANKA’s logbook.

Now I also have a data on the three good batteries and can keep an eye
on them as they age. Only thing left to do is order a new 8A4D battery to
replace the defective battery 1.

WHEN SHIP HAPPENS

I have one critical item on my Spring Outfitting list before bottom painting and  launching BIANKA for

the season. It is to replace one of the four batteries in the 48 volt electric propulsion  
battery bank. Even though the batteries are only two years old it looks like one of them
failed and needs to be replaced due to an error in judgment on my part but, caused by
the freight company that did not secure the batteries in shipping. Herein lies the cautionary
tale for others to not make the same mistake I made.  I converted Bianka to Electric
propulsion in 2008. At that time I installed four 8A4D batteries in series to make up the
48 volt propulsion Bank. They did quite well and lasted for eight years. In year eight one
of them showed signs of failure.

Since it is good practice to try and keep all the batteries used in the same bank the same age. I decided to replace all of the batteries instead of the one that was beginning to fail.  The Battery was drop shipped from a warehouse in Florida and took a week to make it up to Long Island. The four batteries were supposed to be delivered to my house.  However I got a call from the shipping company that I needed to come by and pick them up at the warehouse. I thought this was a little strange but I was too excited and wanted to have the batteries installed on board as soon as possible.   So I made no complaint. I drove to the warehouse on a hot summer day to pick up the four batteries. A couple of the warehouse workers were acting a little strange as I asked about my order and they seemed to take their time bringing out the  batteries with the forklift.

There were a few things I noticed that seem strange but I did not question them at the time.
 First was the batteries were not secured to the pallet, the plastic they were wrapped in was
ripped off of them and the cardboard that covered them  was kind of ripped up too. I lifted up
the cardboard from two of the batteries they seemed okay so I accepted the order and and
I had the workers load the batteries into my car.

It was only after I drove to the boatyard to install the batteries on the boat that I discovered
to my horror that two of the batteries were physically damaged. Unfortunately, these were
the two that I didn't look at at the warehouse. Their lugs were bent over like they had been
dropped on them.

The other two batteries looked physically okay.  Here is where I made my error. I called the company where I bought the batteries and told them of the damage to the batteries and I
would need two replacements. I should have rejected the entire shipment because even
though the other two did not look physically damaged one of them was damaged internally
which I discovered while on one of my cruises last year. It’s voltage would start dropping
rapidly when under a heavy current draw compared to the other three batteries in the bank.
Which is why I plan on replacing it this year. But, just to make sure the suspected bad battery is indeed bad. I’ll do a quick check of all the batteries to confirm my suspicions.

HONDA EU2200i GENERATOR: More Power To You!

My Honda 2000i generator has been a proven versatile workhorse for the past ten years and looks like it will continue to function as such for the foreseeable future.  It was originally bought to be part of my poor man's hybrid system when I converted BIANKA to electric propulsion. It has work well for that and more. It was light weight and easily stored and much more quieter compared  to other generators on the market. Hard to improve on the design. But, Honda has with the new Honda EU2200i model.
The new model   increased the power output by 200 watts.  Which is an impressive 10% improvement in power output. With the same size generator case. In the case of BIANKA this would mean the ability to have a constant 37.5 amps to push my boat along at about 4 knots without draining the battery bank. A nice speed for a 48 pound generator. It would also mean faster charging times when at anchor. Plus there are a few more physical improvements to the generator. Like a bigger oil filler opening and oil drain gutter making oil changes easier and cleaner. There is also a fuel shut off valve so you can run the generator until the carburetor is drained of fuel.  It's very tempting on my part to upgrade to this Honda generator. But,  my frugal side is telling me "If it ain't broke don't fix it". Since my ten year old Honda 2000i is not broke I'm able to resist upgrading to the Honda EU220i. But it's nice to know it will be available to me should I need it on want to.

AN ELECTRIC PROPULSION UPGRADE: Part One

It's been a busy summer for me so I have not been on BIANKA as often as I was in past seasons. But, I finally got around to installing the new upgraded motor controller. This is one of advantages of electric propulsion i.e. is the ability to upgrade various components of the system. The original controller gave me eight trouble free years of operation. But, at the beginning of last season after the boat was launched I went to leave the dock and had no power from the controller. I spoke to Dave at Annapolis Hybrid
Marine about it. He mentioned there had been a few of these mysterious failures of the Navitas 400 controllers and as a result they had changed controller brands. Though the new controller they install does not fit in the same box as the older Navitas TPM 400 controllers.  So as I saw it I had several options (which is another advantage of Electric Propulsion) :

1) Was to keep the current controller box and buy a new NAVITAS TPM 400 controller to replace the dead one. This would be the cheapest remedy. But, even though the original controller gave me eight years of trouble free service there was no guarantee a replacement would do the same.

2) Buy a new box with the new upgraded Sigma controller. This would effectively give me a brand new Thoosa 9000 system. Since the controller is the heart of an EP system. Only the motor, batteries, and a few other things like the Speed control, battery charger would be original.

3) Dave at Annapolis Hybrid offered another solution. If I did not have to use max power of my current system they could fit a smaller controller in my current controller box which would save me the cost of the new controller box. I never did have to pull max amps from the controller so this would probably work for me.

After thinking about it over the winter I decided to buy the new upgraded controller and box. Even though I probably would never draw max amps from the controller I did not like worrying about limitations of using a smaller controller in the current box.  Likewise since the original Navitas controller died suddenly that would also be in the back of my mind while cruising. So buying the new upgraded Thoosa 9000 controller seems like the best way to go.

I'll be showing the installation upgrade procedure in the next Post.

ELECTRIC PROPULSION: SOME THOUGHTS ON ELECTRO SAILING: Part Two

Now that I've shown an example of how I am able to easily Electro-Sail with BIANKA when the winds fail to show up. I'll discuss the components that enable me to achieve it and some of the things I have learned in the past nine years since I converted BIANKA to Electric Propulsion.

My Thoosa 9000 EP system specifications were designed  for 20 miles at 4 knots. This was using my 8A4D AGM batteries only. I have never checked if this was the actual case nor do I want to unless it becomes necessary. BIANKA is a sailboat and I always prefer to use the sail for propulsion. Another reason to avoid trying to push the battery bank close to depletion is you decrease the amount charge cycles of the battery bank. As this chart below shows:

It's about saving the amps champs! But, that does not mean I just use the EP system to get into and out of the harbor. Which is very easy for an EP system to do. I tend to leave my home harbor for other destinations not just day sails. But, EP makes that easy to do too.

So what do I use when I feel the need to Electro Sail? I will first start out under battery power alone. I watch the XBM battery monitor to see when my battery back has dropped down to about 75% battery capacity from the 100% fully charged condition I started out with. This is about two hours after I have started motoring. As noted above this habit allows me to have more recharge cycles out of the battery over it's lifetime. This is better than depleting the bank to down say 50%. It also reduces the amount of time spent to charge the battery back up to 100%

So when the battery bank has dropped to the 75% capacity.  I fire up the Honda 2000i generator and plug in the ZIVAN NG-1 charger into it.

The ZIVAN has turned into a real workhorse and has been very reliable. When I first installed the Thoosa system back in 2008 I was concerned about what would happen if the charger went bad and could no longer charge the battery bank while on a cruise. So I bought a backup NG-1. I'm happy to say that the backup has remained in it's box for these past nine years and has never had to be put into service.  The ZIVAN also works well with the Honda 2000 generator. When I use it for Electro Sailing on BIANKA it functions as a power supply pushing out 15 amps of max current to propel the boat acting as a power supply to push the boat along. It's output is just 900 watts well within the maximum 1600 watts continuous rating of the Honda generator. As the graph below from one of my harbor tests shows that 900 watts allows me to motor BIANKA at around three knots without drawing any amps out of the battery bank:

 In fact it allows me to operated the Honda Generator in ECO mode which makes the one gallon of gas in the Honda generator last for about four hours. I have operated the ZIVAN in this full out mode for hours at a time without issue. BIANKA will move along quite nicely at this speed until the fuel runs out. Of course despite being a fairly sophisticated charger the ZIVAN does not know it is being used only has a power supply to push BIANKA along on a windless day. It thinks it is still charging a battery bank. Which brings up something one has to be on the lookout for when Electro-Sailing with this and other chargers. Because the charger never sees the battery being charged at some point it will disconnect. Thinking the battery is not charging it will timeout. It takes several hours to reach this conclusion and it is easily reset by unplugging it from the generator and plugging it back in. Then it is good to go for another several hours.
 One of the nice things about having Electric Propulsion is how easily it is to modify components of the system or change operating modes. Because the ZIVAN's output is limited to 900 watts it means I am not able to take advantage of the full 1600 watts continuous output of the Honda 2000i. So I am contemplating buying a 48 volt 1500 watt power supply to use when it looks like I will have to operate on an extended Electro-Sail mode. I expect it should move BIANKA along about 4 knots. I'll test and post about that hopefully some this upcoming season.

ELECTRIC PROPULSION: SOME THOUGHTS ON ELECTRO-SAILING. PART ONE

I was awakened from my mid winter doldrums by an email from a fellow who had some questions about electro-sailing if he were to convert to electric propulsion:

"My wife and I are looking at converting our Vancouver 27 to electric. I think electric with approximately 200 amp hour 48v bank would meet all of our needs under normal conditions, but because there may be rare occasions

but because there may be rare occasions, like if we have to transit a canal the like Erie Canal, where we would need to motor for an extended period I am I am trying to determine if a small generator like the 2000i would be suitable to propel the boat at a slow speed for extended periods.

You stated that you could motor at about 3 knots with your 2000i generator. What charger do you use? Have you done this for several hours at a time? I am curious if you have experienced issues with heat build up, or other problems that might be an issue with extended use of the charger to power the electric engine."

These are great questions and ones I wondered about back in 2007 where I began to get serious about converting to electric propulsion. So I thought I'd make a blog post about my experience over the past nine seasons with electric propulsion and electro-sailing.

1) I am trying to determine if a small generator like the 2000i would be suitable to propel the boat at a slow speed for extended periods.

The answer is yes. I have found I don't really need to do it often but I have had to at times  motor up to 40 nautical miles just using a Honda 2000i generator and battery charger to move my 30 foot boat along. An example of such a day is shown in this video:

Again I have not had to do this often since at some point during most sailing days a breeze does kick up at some point. But, even if it does not I find electro-sailing with Electric Propulsion to be much quieter and much less vibration than when I had a diesel which makes for a much more pleasant day on the water.

I'll get into more specifics as to the components used on BIANKA for extended electro-sailing  and the things you need to know to make it possible in the next post.

POSEIDON SPEAKS TO ME: Part Four

So it has finally come down to this. Because of the battery problem which delayed launch. Followed by the surprise of the failed EP Controller. These issues had pushed the idea of sailing even further out in the season. Yes, I could just replace the controller but, Dave at Annapolis Hybrid Marine said they no longer use that controller because several others had  surprise failures too. They are using a new controller but it requires a bigger enclosure box. He had one in stock and I could have swapped it out pretty quickly. But, I had other considerations to take into account. Namely a girlfriends beach vacation and a cruise to Bermuda for my grand nieces wedding reception that would take me away from the boat for additional weeks. I'd not be able to start to fix  things  until mid September. Since I'd probably be pulling the boat in mid October anyway it would not leave much time for sailing even if the weather cooperated. So I decided to scrap this sailing season and use BIANKA as my floating harbor home. I don't have to put the large sail up and I have plenty of projects to keep me busy. Plus I could jump over the side for a refreshing swim anytime. Actually, It's not a bad place to be. Perhaps Poseidon is right.

POSEIDON SPEAKS TO ME: Part Three

I called David at Annapolis Hybrid Marine the U.S. distributors for the Thoosa 9000 systems.  Since the Key switch did not seem to be the issue I began thinking of other things that might easily resolve the problem. One was to disconnect the B+ of the battery to hopefully reset the controller. David said that was not necessary. I then mentioned that the power contactor relay might be bad. David ask if I had a multimeter on board. Of course I did. He suggested I remove the cover to the controller box and he could guide me on making some voltage measurements. This of course means emptying out the starboard locker and squeezing my way to large frame down below in the summer heat to access the controller box. I had not had to do this in eight years of electric propulsion operation because the system was so reliable. But, now it had to be done. I then asked a question that saved me some aggravation. In preparation of my journey down below I asked how many screws hold the cover of the controller box and are they Phillips? David replied no they are Torx (star) type screws. I did not have any Tork screwdrivers on board so I would need to buy them. But, at least I had not found this out after contorting my body down below after emptying out the locker. So it was a row back to land to get a Torx screw driver set to continue trouble shooting.


At the store I had several choices of Tork tools. The first one I picked up was a compact set that folding into the handle. It looked like it would do the trick. Though something told me that maybe I had better have a backup.


So I also bought another Torx set that had a screwdriver type handle with interchangeable bits. 
 Good thing I did this because I found that with the compact folding set it was difficult to access and turn the screws at the rear of the case. Where as the set with the screw driver handle was much more secure and made it easy to turn the screw. But, even then I found the controller box was just a little too close to the battery charger case to use the handle.  I was however able to use just the Torx  bit and a pair of small vice grips to turn the screw enough to remove it.



With the controller case finally removed I gave David another call and armed with a digital multimeter I was able to start trouble shooting.  There is not much to a Thoosa 9000 system. There is of course the battery bank, motor, key switch and a box holding the controller and a few other components.

But, even inside the controller box there are many components that one finds with a diesel engine system. There is a relay, fuses, connectors. The one main different component is the motor controller. In my case it is a Navitas 400 unit. Under Davids guidance I carefully connected the multimeter ground to the B- battery connection in the box. I then checked the voltage at the power relay connections. Which was the component I thought was the next culprit after elimination the key switch. I measured 55 volts which was full battery voltage on both terminals.  David explained that it looked like the the relay was good because 55 volts on both terminals means the coil of the relay is not open. What happens on turn on is after the Controller does it's self check it grounds one side of the relay which then allows full battery power to the controller. This was not happening. So it was time to look at the controller. There were two status/fault lights on one side of the controller neither one was on. David then instructed me to probe two pins on the multipin connector  to the controller module.  There was 55 volts across those pins. This meant the controller module was getting power. So the diagnosis is the controller is bad. David mention this had happened to other units and as a result they were no longer using the Navitas controllers because of these mysterious sudden failures. Stil I had gotten eight trouble free years out of this one and could easily replace it but, I was thinking it might be best to upgrade to the new controller David mentioned. Trouble is the new controller is larger and won't fit in to the current box. He said I also needed to check if the new slightly larger box dimensions would fit in the current space. I'm pretty sure they would but, I want to make sure and while I'm at it I want to mount it so I will be able to have enough roof to use the Torx screwdriver handle to remove the cover in the future.

 So a quick ten minutes of probing and the problem was quickly diagnosed. Compared to the hours I and some diesel mechanics I had hired in the past spent scratching our heads working on the diesel it was a breeze. Unfortunately, it is getting late in the season and I would be away for several weeks. So I had a few things to think about before I decide to move ahead with a new controller box which I'll share in an upcoming post.

POSEIDON SPEAKS TO ME: Part One

Well, this ninth season with electric propulsion has certainly been one of two steps forward and one step back. Looking back at how things have gone it certainly seems as if the Gods are conspiring against BIANKA venturing too far off the mooring after eight years of pretty trouble free operation. To recap:

Spring outfitting was going well as usual until a few days before I was planning to launch. I plugged into grid power to do one final charge in the boatyard before launch when I noticed one of the batteries was not reaching full charge. Some further testing showed it was going bad and would need be replaced.

Since all the batteries in the bank were eight years old replacing only the bad battery created my first dilemma. By only replacing the bad battery in older 48 volt battery bank results in the older batteries degrading the new battery. So in a few years I might have to replace all of the batteries again. So I decided since the battery bank was eight years old I'd replace all of them now. So that's what I did.

Unfortunately,  shipping damage made two of the new batteries unusable and required replacements to be ordered further delaying installation of the new batteries. Poseidon must have had Thor or whoever the God of shipping is throw the batteries around in the truck to damage them.

Since I would be removing the old batteries. I decided now would also be a good time to reconfigure the position of the batteries so they will be easier to access and service in the future. But, I needed to extend the the battery platform to do this. This was the time to do this but, it meant an additional delay while I worked on how to extend the platform.

Once that was done it was time to install the new batteries which went well. With the new batteries installed and rewired it was time to head out to the mooring. I turned the systems main power and then the key switch to engage the contractor relay. Nothing! For some reason the relay was not energizing and providing battery battery power to the controller and motor for operation. Poseidon is laughing at this no doubt.  I'd been at the boatyards work dock for a week and the boatyard was getting antsy for me to move out of the way.

I thought it would be a simple problem with the Key switch that tells the controller to engaged the contactor. Certainly eight years with the switch exposed to the elements had caused the switch contacts to fail. Something I could easily fix while at the mooring.  It was now already well past July 4th I was also anxious to get out to the mooring where I would also be able to jump off the boat for a swim in the summer heat. So I told the boatyard to tow BIANKA out to the mooring where I thought I would be able to quickly fix the switch issue and finally start the sailing season. Unfortunately this was not to be the case...

TO BE CONTINUED

BATTERY INSTALL 2016

The sailing season has been delayed while I deat with the damaged battery SNAFU. Two new 8A4D batteries arrived to replace the two that were damaged in the original shipment. The only difference is that the batteries probably have different manufacturing dates. When I ordered the original batteries the battery company said it could provide batteries manufactured the same day. But, now that probably is not the case. Whether or not it will make that much of a difference only time will tell.
So I loaded up all five hundred and twenty pounds of batteries into the car and took them to the boatyard.

I had BIANKA launched because it would be easier to load the batteries into BIANKA while floating at the dock.
I did make some major changes in the placement of the new batteries. I reversed the location of the the terminals of batteries one to three. I just turned them around so all terminals are located along the port side. Battery four was off by it's self next to the other batteries facing aft on the starboard side. The was because the engine stringer which held up the original battery platform did not extend far enough aft to allow for the fourth battery so I installed it next to the other three. Unfortunately this also meant I had to empty out two cockpit lockers to do any maintenance on the pack instead of one. It was a real pain.
By building a metal extension battery holder out of slotted angle iron and extending it off of the existing platform:

I was able to line up all the battery terminals on the same side and make them easy to reach after only emptying one of the cockpit lockers. This will make for much easier access and maintenance in the future.

 Other than doing the install on the hottest day of the year the install went pretty good. There might be some tweaks I might want to do but, they could wait until the off season. The next step is to get the batteries wired up. I did have some concern that since I changed the layout of the batteries that one or both of the main battery cables would not reach the proper terminals. We'll see how that works out once I start wiring thing up.

MY BATTERY REPLACEMENT CHOICE

A new set of batteries should be arriving today to replace the original eight year old 8A4D batteries on board BIANKA. Due to the failure of one of the batteries I thought it best to replace the whole lot. While the remaining batteries seemed to be in good enough shape they would only degrade the new battery.  This would require me to do another whole swap in a few years anyway. I looked into Lithium Ion replacements and the economics just did not quite make sense yet because of the increased price and other add on items I would have to buy like a new charger. I found a 48 volt 200 amp hour Lithium Ion battery for around $5000. For the same amount of money I could replace all my AGM's two times and still have a sizable chunk of cash for other boat needs. The AGM's should last me a minimum of sixteen years based on my experience with the first bank. If Lithium prices come down as they have been predicting I will revisit the issue but, for now I'm going with what has worked for me the past eight years.

BATTERY ANOMALY: Part Three: Additional Testing

After another day of charging I did some more tests of the suspect battery using the Centech Meter. This time the battery resistance reading had dropped to 9 milliohms. A big improvement from the 194 reading but,  still three times what I had measured back in 2012. In addition the meter said I only had 335 Cold Cranking Amps available from the battery. Manufacturing spec says it should be 1100. So even though after several charging attempts the battery is really not up to snuff and will need to be replaced.

I then decided to some quick tests of the other batteries in the string using the CenTech meter. Starting with the first (most positive battery in the string:

As the above photo shows this battery had 1404 Cold Cranking Amps available. So at least with this test seems good. Next I checked Battery Two:

   

As the readings above show the results are not as good as the first battery. In fact it only shows 884 Cold Cranking Amps available. Not as bad as the suspect battery but, under the spec of 1100 CCA.
Battery three was tested next:

This tested better than battery two but, not as good as battery one. At 1150 Cold Cranking Amps it was just over the battery specifications but, not by much.

After doing these tests and thinking about the age of the batteries I came to the conclusion that it would be better to change out all of the batteries in the 48 volt string. In addition after doing these test in the confines of the under the cockpit space I decided I would position the batteries differently to make access for future testing easier. The next question is do I go for Lithium Ion batteries or stick with the AGM's?

TO BE CONTINUED

BATTERY ANOMALY: Part Three: Additional Testing

After another day of charging I did some more tests of the suspect battery using the Centech Meter. This time the battery resistance reading had dropped to 9 milliohms. A big improvement from the 194 reading but,  still three times what I had measured back in 2012. In addition the meter said I only had 335 Cold Cranking Amps available from the battery. Manufacturing spec says it should be 1100. So even though after several charging attempts the battery is really not up to snuff and will need to be replaced.

I then decided to some quick tests of the other batteries in the string using the CenTech meter. Starting with the first (most positive battery in the string:

As the above photo shows this battery had 1404 Cold Cranking Amps available. So at least with this test seems good. Next I checked Battery Two:

   

As the readings above show the results are not as good as the first battery. In fact it only shows 884 Cold Cranking Amps available. Not as bad as the suspect battery but, under the spec of 1100 CCA.
Battery three was tested next:

This tested better than battery two but, not as good as battery one. At 1150 Cold Cranking Amps it was just over the battery specifications but, not by much.

After doing these tests and thinking about the age of the batteries I came to the conclusion that it would be better to change out all of the batteries in the 48 volt string. In addition after doing these test in the confines of the under the cockpit space I decided I would position the batteries differently to make access for future testing easier. The next question is do I go for Lithium Ion batteries or stick with the AGM's?

TO BE CONTINUED