Project: Boat Power -Results

While in NZ we made a few changes to Elysium. One significant change was in our electrical power system. When we arrived in NZ we needed new batteries. We had been nursing our House and Starter bank for the last year or so. There had not been any place to get high quality batteries while in the Pacific; at a reasonable price. We could have shiped them in to an island but the cost of shipping would far out weigh the cost of the batteries. In NZ the equation would change.
But; and this is rather significant; while in NZ we ran into Phil on Silhouette. He was an electrical engineer in his pre cruising life and had run Lithiums on his boat for the last 2-3 years. He talked about how wonderful they were – all – the – time. And while we were in NZ other cruisers I know; Mark on Reach, Martin on Katie M II, BJ on Evenstar, and Paul on Anticipation  (all knowledgable sailors I respect) had either installed or were installing them. Not that we follow the crowd. 🙂
However; I do love using others as our “guinea pigs”. For the most part they too understand this lifestyle. They have the same experiences managing their electrical needs. On yachts we must blance charging, using, maintaining a battery bank, and the equipment while we keep it all working smoothly. With the guidance of those wiser than I, Elysium set about upgrading her electrical system… to Lithiums.
First was selecting and purchasing the batteries. I could have paid extra and had a local installer do all the work. The cost would almost double what I had hoped to pay. Instead; considering how cheap I am (and a bit concerned that I don’t want anyone else to blame but myself), I planned on doing the work myself.
I ordered them, as per Phil, from the Chinese shop in Taiwan. According to his information; China has spent billions of dollars in making this storage device perfect. The Chinese see the future. For the most part this technology is driving the new generation of electric vehicles. When on a yacht, in the middle of no where I want something that is not on the cutting edge. I learned in the working world that being on the cutting edge one quite often bleeds. Thus, I followed Phil’s advice and went with the China batteries.
The one real issue was that the supplier didn’t take any credit cards. There was no website and once they quoted you the amount; to buy the batteries you needed to make a bank transfer; roughly $3,500 US. After that I held my breath. They provided us confirmation of the receipt of funds but then there was a black hole in communication for a few weeks. Finally, I received a bill of lading for the batteries. And about 2 months later they said the batteries were shipped. I still worried. Four weeks later I received a note that we had some merchandise in Auckland. One would think that because we are a boat in transit this would be easy. In some respects it was; in others not so much. Of course the shipper could take care of everything and ship the batteries to Whangarei. The cost; another $500 NZ or so. With a car we opted to make a day trip to Auckland and run the paper work down ourselves. . We had left Whangarei in the a.m. timing our Auckland arrival to be immediately after rush hour. We arrived at the shipping agent by 11 am and found customs around noon. After completing the paperwork we began looking for the shipping warehouse and by 2 ish had located it. Thirty minutes later we had two boxes of Lithium batteries loaded in the trunk of the car and were heading home. I, was much relieved.
Phil on Silhouette was advising me. He said I didn’t need all the “rig a ma role” to use the Lithiums. And I wanted to follow the KISS (Keep It Simple Stupid) principle. Once we had the batteries on the boat I removed the older gel batteries and we took them to a recycle depot. There we received almost $100 NZ for the batteries I didn’t want and wouldn’t hold a charge. Sweet! I kept one 12 v battery to run the boat with the battery charger.
First order of business was to “Balance” the batteries. Some “experts” say to balance them at the bottom of their charge and others say to balance them at the top. Phil indicated that one really didn’t need to do either as they would balance out anyway once connected. So, in lieu of buying a constant voltage charger or draining them to near the bottom and recharging them I simply connected them in parallel and let them self balance. Before any of you get up in arms about that, since I’ve installed and had them in operation over 6 months no pack voltage has been off by more than 0.01 V. I would say the avg difference is 0.006 V but my instruments don’t read to that minuscule amount and I’m having to interpolate.
Once balanced Phil said I needed two latching relays. We spent a good hour on the internet looking for exactly what he suggested. We needed relays that would handle high amps. What we found was going to cost me close to $500.00. Ouch! There goes simple!
Traveling back in time W/ and I had done a house sit for Scott. who owns EMPower Electrical. He is the “go to guy” for Lithium installs in Northland NZ. While at his office he was telling me / showing me about how their company sets up Lithium installs, the BMS they use and the switches. The cost of the hardware was close to a grand NZ! Ouch. Often during this process I was wondering if we had made the right choice. I had already crossed this bridge and to turn back would not save us any $$$’s. All I could do was barrel on ahead. The question was do we install all the bells and whistles for $1000.00 or do I have a minimal system with hope, a prayer, and $500.00 extra in my pocket. I decided to bite the bullet and get the complete Battery Management System (BMS). I bought the hardware from EMPower and Scott would advise me on what to do. Once I had the work completed he would check it all and bring everything up online. Of course that was more money but I’ve already taken hold of the hook.
A couple of days later he brought me the Orion BMS, wiring harness’, automatic battery switches and some extra battery cable. If I ever thought this was going to be easy; boy was I mistaken. During our first consult he drew a new wiring

Out with the old...

Out with the Old…..

diagram. Our boat is / was mostly old school. All charging and load sources were brought to individual power posts. Whichever battery bank I wanted to use were switched at the panel and run to the power post. That was NOT what I needed to do with the lithiums. ( Side note on Orion:  I’ve needed to communicate with the company via email a couple of times and they have been excellent in responding in a timely manner and answering my questions completely)

Lithiums needed to have the load and charge separately controlled. They die one of two ways: Over charging and being discharged flat. What this process entailed was installing some new wire runs. We have two alternators, one on each engine and an 80 amp battery charger. I needed to run new cables from the alternators to the lithium compartment and from the battery charger to the compartment. I was also going to add some solar panels. (Another blog entry will cover that). Solar too will need another cable feed into the charging post / switch. The Battery Monitoring System will shut off the charging of the batteries when they reach whatever setup point is entered-preventing them from overcharging. From my research Lithiums are 100% charged when they reach 14.4 volts. I set the BMS to shut down the charging a 14.3 volts. Lithiums have no need like other batteries to ever be at 100 % during any part of their life. On our regulator the max charge point is set to 14.2 volts. This ought to keep everything healthy, never really charging the batteries over 95%.
After a brief interlude of cursing from having to re route wiring W/ and I set about completing this job. Any yacht owners having read this far might well listen to the following advice. Anytime you run a water line or power cable through any bulkhead on the boat, double the size of the hole you believe you will need. DOUBLE IT! It NEVER fails that you will need to run more wires or more hose through that same hole. And as any woodworker understands: You can NOT enlarge a hole with an electrical cable or water line running through it. You either need to remove the cable / hose and recut the hole or add another next to it. At times there are several cables passing through the same hole. It would be quite problematic to remove them, enlarge the opening, then reinstall them. I opted to add more holes.
A couple of days later and a 100 wire ties fewer I had the change cables run. The next step was to remove the load from the power post at the panel and move it back to the lithium compartment. Again with a colorful language and W/’s support I set about pulling the load wiring and re routing it to the lithium bank. The idea here is that with an extreme discharge of the bank I could kill the batteries. Near future replacement is not in our budget. I have the minimum capacity of the bank set at 20%. All of this work including the language lapses took a couple of weeks to complete. (I’m retired and don’t work 8 hour days anymore! 🙂 ) I would run out of wire, need another power post, or simply run out of patience and need a break.

Lithium yacht power installation; overwhelmed.

Once completed I called Scott and scheduled a time that we could actually bring the system online. One item I was missing was a cable that connected the Orion BMS to my computer. Well, that and the BMS configuration file. Scott had both. I had ordered the cable from TradeMe; the eBay of NZ and was waiting for it’s arrival. But I still needed / wanted Scott to check everything and have the system functioning right the first time. He checked the wiring, checked that all the connections to the Lithium cells were correct, checked that the load and charge switches worked and then made the final connection. After that we checked to make sure my Ample Power EMON read the same voltage that the battery pack indicated, ran the charger and bingo… we were up and running. He advised us to run the charger up to where we had set the batteries for full and then I would be all good to go.

There was however one other concern I had. While discussing this setup earlier at Scott’s home he said that when running correctly the system will shut down the alternators before it disconnects the charge source. If one shuts down the charge source while running the alternators then you blow the diodes in the alternator. When off shore or in remote locations- that is not good. I was not interested in blowing out any diodes. He has another (yes I know) switch that I could wire into my regulator. Thus when the BMS tells the battery switches they will be shut down in 5 seconds, the system immediately disconnects the power to the regulator thereby shutting off the alternators. As that is a latching relay it will not repower the regulator until the BMS indicates that the batteries can now take more power.
For the most part; this setup is for safety. That and saving me from needing to purchase more batteries in the near future. Safety on a cruising boat is the first priority. And while I am by no means a conservative individual, sailing, when W/ and my life depend on everything working well: I am quite conservative.
As a rough total we have about $6,000.00 US invested in this battery setup. That includes a spare BMS ( I picked it up off of eBay), two new CAN regulators (they will actually talk to the BMS and are not yet installed- maybe this year), the extra cables and switches and the consulting bill from EMPower. In a worse case scenerio this battery bank will reach 2,000 cycles before degrading enough that I will need to replace anything again. Elysium is using about 10 cycles / month which would give us close to 200 months of full time cruising use. That comes out to about $1.00 / day for storage and use of our batteries. Not bad.
Remember I said whilst in the middle of this install I was wondering if I was doing the right thing. No longer. In our old system we had an effective amp hour usage of a maximum 200 amp hours between charging. In a typical lead acid battery for deep cycle use you only get 50% of the rated amp hours. In this current setup we have almost double that. To top it off, the charging of this bank is more efficient. A lead acid charge cycle voltage will taper off the closer you get to a full charge. For lithiums, I am charging at my full capacity for the majority of my cycle. I am getting the full benefit from my solar panels or my alternators all day long. Lithiums have been a good choice for Elysium. W/ and I no longer worry about using too much power. We no longer worry if our battery bank is below 50%. It is all taken care of . Hell, we even bought a Toaster and run it off our Inverter! W/’s happy, I’m happy, life is good…
 
Go Slow
Sail Far
Stay Long