LiFePO4 for House bank final designs

[exMaggieDrum]

JBPohle - nice installation. I like the fiberglass angles you used. I may get some of those.

MaineSail - The Mastek is running at 15-16A when starting on each cell so is about 75% of the 20A capacity. I took that from one of your posts or from your blog. It is taking about 5-6 hours per cell to go from the 3.29v they came up to 3.61-3.62v when I take them off as single cells. Getting them to 3.65 on a single basis is very dicey as it is close to the knee and the Masteck's "fine voltage" control is not very fine at all. I end up just barely tapping it to get it close. I will put the whole set in parallel at the end and do them as one for the final push to a consistent 3.65V. Note: The Mastek manual emphasized the importance of not having the charge wires connected to the battery when turning it on, and never/ever turn it off with it connected to the batteries. I warm it up for 15 minutes with the terminals off and then put it on each cell. I take them off before turning the power supply off. They say it will severely damage the power supply to turn it on or off while connected.

Typhoon, - I too have printed out MaineSail's blog and have underlined and marked it up extensively. Your advice is well taken. I look back at it all often as my brain can't retain all the important little tidbits forever.

Aside - Nigel Calder has an interesting article in this issue of "Sail Magazine" entitled "Hybrid Redux". It is not about using lithium batteries as house batteries except in a few references in building a complete hybrid propulsion system (serial or parallel) that also includes charging house batteries as part of the whole management scheme. As he notes, it has been a mixed bag as far as workable systems for the masses, with some slow progress being made. He does give a synopsis of state of the art battery types, giving a nod to carbon and thin plate AGMs. He seems to think they will eventually get good enough so that lithium is not required.

I am continuing to rewire my DC panel and at the point that I am stubbing all the DC positives to terminal strips. It is tedious and time-consuming with many opportunities to make a mistake with re-labeling each wire. I'll then take new wires from the terminal strips to my new BS panel in a nice tidy fashion. I'm excited. Then it's on to the big cables (and getting the three 8D AGMs out. I'm glad I have some strong friends who owe me. Putting in the lithiums will be a snap! Each set of four cells in parallel are exactly 30# including end plates. And they will fit where one 8D sat.

As always, keep the suggestions coming!

Joe

[JayH]

Originally Posted by exMaggieDrum

Note: The Mastek manual emphasized the importance of not having the charge wires connected to the battery when turning it on, and never/ever turn it off with it connected to the batteries. I warm it up for 15 minutes with the terminals off and then put it on each cell. I take them off before turning the power supply off. They say it will severely damage the power supply to turn it on or off while connected.

This is very true. Mine was destroyed when I lost AC power while it was connected to the batteries. Mastech declined any assistance since it was stated in the manual not to let that happen. Seems like a pretty poor design for a device that claims to be ideal for charging and equalizing batteries.

[ColdEH]

Hey Joe one thing you may notice about my install in my video is that I used braided copper tinned cell connectors. I read of a few cell failures in the electric car retro fitter market of cell failure's due to post loading as the cells expand and contract from temperature variations . I know us boat guys don't charge them or discharge them as fast as the car guys and we rarely even get our cells warm but we do want these batteries to last twenty years and not 20 months so I got these flexible connectors just to make sure there was no post loading going on .

Regards

[exMaggieDrum]

Originally Posted by typhoon

Hey Joe one thing you may notice about my install in my video is that I used braided copper tinned cell connectors. I read of a few cell failures in the electric car retro fitter market of cell failure's due to post loading as the cells expand and contract from temperature variations . I know us boat guys don't charge them or discharge them as fast as the car guys and we rarely even get our cells warm but we do want these batteries to last twenty years and not 20 months so I got these flexible connectors just to make sure there was no post loading going on .

Regards

Actually I did note your connectors and I wish I had some, especially between each paralleled set of four to the others to put them in series. I have a pretty good setup for holding the paralleled cells together. I'm not sure if the distributor put them on that way or they came from Sinopoly that way. I think it was the former. Any way they seem pretty stout.

Of course, the best line of defense is to not let them get too hot in the first place. I have been monitoring each cell's temperature with an infrared meter and they have never got higher than 70F in my 65F garage.

I tried to contact a couple of cell distributors in the US by email to their sales addresses and neither even gave me the courtesy of a reply.

I tried to attach some pics of my cells as they were shipped but I need to downsize them to get them on here.

[exMaggieDrum]

Pics of my batteries as they came out of the shipping container:

[ColdEH]

Mine came the same way .



Regards

[ColdEH]

I got my connectors from a company in Australia , it was awhile ago but I think these were the guys. Got them very fast.


EV Works Braided Cell Interconnector 70-8 70mm nominal pitch, 8mm holes

Regards

[JBPohle]

I got braided connectors from the guys at EVTV. Great folks who loved to talk. I enjoy supporting them.


Sent from my iPhone using Cruisers Sailing Forum

[mbartosch]

I sourced the tinned braided copper strips from http://hesselmann.de

They sell ready made strips (http://www.hesselmann.de/data-downlo...ssebaender.pdf) but for my purpose they were too long.

Contacted the company and got a very competitive offer for custom made braided strips with exactly the dimensions I needed. Great service and product quality.


Sent from my iPhone using Cruisers Sailing Forum

[gpeacock]

Originally Posted by JayH

This is very true. Mine was destroyed when I lost AC power while it was connected to the batteries. Mastech declined any assistance since it was stated in the manual not to let that happen. Seems like a pretty poor design for a device that claims to be ideal for charging and equalizing batteries.

For those who are concerned about loosing AC power while charging with these current/voltage limited bench power supplies (happens all the time in a boat yard), pick up a power supply that has diodes to prevent backfeeding the supply from the batteries. This will keep it from dying when the AC kicks off or you realize the voltage is running away and want to quickly end the charge.
The presence of a diode will mean the voltage wont be as accurate but you'll want to use a meter anyway.
I haven't asked but Mastech or Volteq can steer you to an appropriate one Im sure. My local electronics shop had both types avaialble and explained the difference between them.

My batteries are on their way and I've decided to just use my 12 V battery charger. It will be a slow tedius top ballance with 50W resisters getting attached to the higher Voltage cells as required but I figure, Ive only got to do it once and I don't want the extra gear to stow on my already very full boat.

[exMaggieDrum]

Originally Posted by typhoon

Mine came the same way .



Regards

Unless you got yours from the same place in Canada, the factory must be shipping them this way.

[exMaggieDrum]

Originally Posted by gpeacock

For those who are concerned about loosing AC power while charging with these current/voltage limited bench power supplies (happens all the time in a boat yard), pick up a power supply that has diodes to prevent backfeeding the supply from the batteries. This will keep it from dying when the AC kicks off or you realize the voltage is running away and want to quickly end the charge.
The presence of a diode will mean the voltage wont be as accurate but you'll want to use a meter anyway.
I haven't asked but Mastech or Volteq can steer you to an appropriate one Im sure. My local electronics shop had both types avaialble and explained the difference between them.

My batteries are on their way and I've decided to just use my 12 V battery charger. It will be a slow tedius top ballance with 50W resisters getting attached to the higher Voltage cells as required but I figure, Ive only got to do it once and I don't want the extra gear to stow on my already very full boat.

I didn't even think about the issue when I got the power supply. At home it is not a big deal since the AC power is pretty reliable. In a boat yard, or on a marina dock, it certainly would be. My shorepower is constantly going off for maintenance, storms, whatever. My marina lost the big transformers at the head of my dock a few months ago.

I wasn't planning on putting the Mastek on the boat as I hope my existing charging systems will keep them up. So I may have a almost new power supply to sell later after I get settled in with the new cells.
Joe

[JBPohle]

This weekends effort for the new LiFePo4 installation is shown in the pictures below. Used a "budbox" with bakelight sheet to mount the circuit boards to. This sheet is then secured with screws in the box. I brought the leads from each cell through the big gray cable with 9ea 18ga wires to the House Power BMS Cell Boards 2ea since this is a 24V bank. The control board only has power to it so far.

Next up installing the fuse, Remote Battery Switch and alarms. This would be next weekends project, but the bow thruster is working intermittently (not a good thing). Think we need some new solinoids. Cleaned them up last year and inverted the disks, but they were pretty badly burned.

My new favorite tool and wiring method are uninsulated wire ferules. I used these to treat the ends of these small wires and they really clean up the mess. Easy to use and I like the way the screw down connectors engage them without cutting or damaging the wire.

Also extremely handy are the heat shrink wire labels. With this snakes honeymoon of wiring having the wires labeled made it easy to keep track of which wire went where.

You can also see in the picture a CellLog 8S while it feels a bit like a toy and may not be perfectly precise, but it logs data and will be useful for review trends and diagnosing issues. The budbox will live under the stairs leading from the salon to the staterooms below.

Thank you again to all of the contributors to these threads. This is an interesting project and I've learned a great deal so far.

John

[PacificGreen]

Originally Posted by offpist

It consists of 4 pcs 1000AH Winston cells.
I got them from here:
EV-Power | WB-LYP1000AHC LiFeYPO4 (3.2V/1000Ah) Special product

And BMS from here:
REC d.o.o.

Two Tyco EV200 relays controll charge and discharge.

Had it for 1,5 years now, and works flawless.
We even stopped using gas, only cooking our food on induction top off the 3000W inverter..

Really nicely done and you have done 12v on a boat the way it should be. And from your other posting further down yes post loading on many small connections is just not what you want on a boat. The smaller bolts from my experience just eventually will become loose especially if there is any amount of heat generated upwards of fifty amps.

Less connections and the most amount of amp hours for the buck. Plus you have an actual usable amount of energy in a chemistry with what must be next to unfathomable C rating for charge and discharge. This is where traditional 12 users fail to realize the shortcomings of their anticipated 12v systems as they are always at the top of the C rating on smaller cells from charging with alternators or say for example in the case of what some 12v chargers are capable of charging at for example anything over 100amps.

That is a lot of current and at 12v heading into small bolt holes and bus bars into batteries that are very quickly held at their C Rating for charge.

[offpist]

Thanks.. yeah we charge close to 250A continuous from two Balmar AT200 and external Mastervolt MBII regulators. When the solar is also putting out 40A+ we are getting close to 300A. Still we are under 0,3C..