Inqism-03: Electrifying

[Inquisitor]

This project will be to convert MX from a dead deep-cycle lead-acid battery to Lithium and add all the bells-and-whistles of a full electrification. Not just the lights as are currently in a stock M. Specifically, I've chosen to go to LiFePO4 for its robustness, longevity and power density. For instance, this chemistry seems to be geared to a European test where they actually drive a nail through all the internal plates and it doesn't do anything threatening. It also won't burst into flames from over-charging or discharging too fast. The one's I'll be using are designed to handle 2C discharge (540 Amps) without major degradation. Although capable of many cycles with even 100% discharge, I'm going with a large battery pack that I believe, I'll never get below 50% discharge... its life should outlast mine.

Good (long) read about pros/cons of LiFePO4 (LFP) batteries: https://marinehowto.com/lifepo4-batteries-on-boats/

I've been haunting another forum for doing off-grid solar https://diysolarforum.com/ learning about systems. Being DIY minded anyway, and saving a butt-load of money, I decided to build my own battery also. I'll be doing the build on both this and that forum so that anyone that is of similar interest can follow along... as well as people more knowledgably can steer me into safer/better waters. I had another thread here viewtopic.php?f=8&t=27974 showing where I was heading and got some great feedback already. I am in the process of ordering this stuff... Black-Friday and Cyber-Monday sales helping some. Some of this will be coming via slow-boat from China, so the build will be slow. Here's where I am so far:

Prices include shipping and taxes
For the Noob's in the audience, of which I am one, I'll include verbiage on what it does and why I got it. Some are remedial, and I add just for completeness. Please don't take offense - I'm not talking down to anyone!

1. Solar Panels $171 - These will charge the battery in sunlight. Two panels as described in old thread (see it for review) https://www.amazon.com/Richsolar-Polycr ... ast_sto_dp These were shown to be as good or in some cases better than Monocrystalline panels.
2. Charge Controller $136 - (ON SALE till 11/30/2020) I was about to go with the recommendations of the other site that said Victron was the best. However, after visiting Victron's own forum, I found some customers saying how they had to turn off their controller during VHF. Specifically, it also interferes with AIS frequencies. And if I want something to go out, its certainly to let freighters know where I am and for me to know where they are. paula_ke - viewtopic.php?p=332067#p332067 got me checking. Also, trading email with Robert at DIY SOLAR FOR U was very educational about some pre-conceived notions I had about battery chemistry. And his detail about the company's background being primarily about RF verification and FCC class B compliance. Also, on their site, it shows details about the superior energy gathering of their product compared to PWM ~2x better... but even competitor's MPPT being ~15% more. And... better handling of partially shaded panels. https://www.diysolarforu.com/store/c1/S ... Controller
3. Battery ~$450 - This is for the energy storage. The battery I was going to get in the previous thread was an off-the-shelf unit. I've decided to build my own with individual cells (more about later). My old battery was a 45lbf, 75Ahr deep-cycle, lead-acid battery. To get any kind of life out of it, you could only discharge it about 40%... thus ~30Ahr. I was able to shoe horn it in next to the starter battery under the steps. The new battery should fit in the same area and will weigh about same depending on battery case I buy or build, but will have 270Ahr. At 100% discharge, the life is expected to be 600 cycles or the way I'll be using it, closer to 5000 cycles. I currently have a quote, but have not quite pulled the trigger.
4. BMS $125 - This is the Battery Management System. There is no equivalent when using lead-acid chemistries and any off-the-shelf lithium batteries will have this unit built-in. Lithium cells are more electrically fragile than lead-acid and need to be controlled more accurately. The BMS makes sure that the cells are not abused. It will NOT let you overcharge, discharge, overcurrent, over temperature, under temperature when charging. The BMS also controls charging of the individual cells so they keep in balance with their partners. There are four cells in a nominal 12V battery. This high-end unit has a great reputation on the other forum and includes Bluetooth communications an a app to monitor its state. I traded email with Steve at Overkill Solar and gained knowledge about how to size my inverter to handle nominal and inrush current. https://overkillsolar.com/product/bms-120a-4s-lifepo4/
5. Inverter $235 - This converts DC current back into 120AC for our required toys. I really don't have anything planned to be AC dependent except maybe a blender, but it will be there when needed. 1500 watts can drive a microwave or even a small window air-conditioner. I don't expect to do either... just it'll be there when I need. https://www.amazon.com/dp/B08MKZPD66 EDIT - Getting a different one than this. See details below.

TOTAL so far: $1117

These were the big chunks. There will be more things added... things that will go into the boat like fuses, circuit breakers, wire, lugs, and sensors. There will also be some things I need to do the build like AC charger, capacity meter, etc. I'll flesh these out as I go. I want to have a final number that people can see what they're biting off ahead of time.

[Inquisitor]

• 300V 100A DC digital voltmeter, ammeter, battery capacity tester $29 - This allows me to validate the cells. After topping them off, they will be discharged through this and on to the inverter. Something big like a heat gun can supply the load. After they are fully discharged, this board will report the total Watt-hour capacity. Ordered on ebay from China.
  
  

Outlay Summary: For boat $1117 Test gear $29

[Jimmyt]

Great project! Thanks for posting the details. Very informative!

[Inquisitor]

I imagine our forum has experts and novice in many fields. I am not an expert in this one. This is my trail of discovery (and money savings). I hope the experts will keep me between the lines and it will help others take the leap. If you are an expert and can shed light on something, please do. If you are more novice than I, and I use a term you don't understand, message me and I'll elaborate either privately or in this thread.

• AC Charger $58 (Cyber Monday Sale) - https://www.amazon.com/gp/product/B087TK6ZM2 This is a work-bench type, variable AC-DC converter. It's maximum rating is 30V and 10A. This was the "Amazon Choice". Although it is not specifically designed to charge LiFePO4 batteries, it can be used in several ways:
  1. to charge the cells individually - Nominal voltage 3.65V. The cells I'm getting can be charged up to 270 Amps. 10 Amps is considered a trickle charge in comparison. Wires will be the limiting factor.
  2. to charge them in parallel - Nominal voltage 3.65V. It'll take more amps than you could ever safely deliver.
  3. to charge them in series - 14.6V. The cells I'm getting can be charged at 270 Amps this way.
  4. I play around with microelectronics - Raspberry Pi, Arduino and primarily ESP8266 / ESP32 boards. I can use this on my electronic work bench.
  5. Also read this makes a great power supply for doing aluminum anodizing. I can see doing some more MX projects that involve anodizing some aluminum... maybe even the color kind.
  6. What do you all use to convert shore power to charge? Can I use this? Although I don't plan to add shore power ability, it might be an option for someone. In my case, I hope the panels will be enough.

Outlay Summary: For boat $1117 Test gear $84

[Jimmyt]

Just going back through your components, and I see your battery monitor/meter is 100 amp. You also discuss the possibility of running a 1500 watt inverter load. Although you didn't specify your bank voltage (and since you're building it from scratch it could be anything), I'm assuming it won't be over 13 volts so you can run 12 volt accessories. All of that rambling to say, you're at the limit of your battery monitor at 13 volts and 100 amps, so 1300 watts direct load off the bank should probably be your plan limit. After running through the inverter, you'll probably be able to use a bit less than 1300 watts due to losses.

Since you didn't show how all of this is planned to be connected, I am assuming that your battery monitor would be covering all bank loads. If your inverter is wired around the monitor, ignore this comment.

[Inquisitor]

Just going back through your components, and I see your battery monitor/meter is 100 amp. You also discuss the possibility of running a 1500 watt inverter load. Although you didn't specify your bank voltage (and since you're building it from scratch it could be anything), I'm assuming it won't be over 13 volts so you can run 12 volt accessories. All of that rambling to say, you're at the limit of your battery monitor at 13 volts and 100 amps, so 1300 watts direct load off the bank should probably be your plan limit. After running through the inverter, you'll probably be able to use a bit less than 1300 watts due to losses.

Since you didn't show how all of this is planned to be connected, I am assuming that your battery monitor would be covering all bank loads. If your inverter is wired around the monitor, ignore this comment.

Thank you JimmyT! You are a gentleman and scholar... and are very observant. SOMEONE definitely needs to keep me in line. An overview is definitely called for and will give people a chance to show me the error of my ways. I like pictures and will started generating one up.

As for the battery monitor (described in viewtopic.php?f=8&t=28020#p346304) - This monitor is intended for testing of the battery only. If you were to buy a pre-built LiFePO4 battery like the one in my previous thread, it comes with the 4 cells and a BMS inside the plastic or metal shell. Building the battery from the raw cells, I need to verify I'm getting what is promised. The pros/conns are:

Cons

• I need to purchase some test equipment that wouldn't be needed otherwise. I rationalized those away for other projects or other battery builds. Maybe take my house solar powered and off-grid.

Pros

• Way cheaper / way larger / way lighter - Depending on how you tally it up. The pre-built LiFePO4 battery is only 100 Ahr, 35 lbs for $650. This battery will be 270 Ahr, 55 lbs for about $600 depending on what I do for a case. Some reference on this website had 100 Ahr, 120 lbs worth of high-quality AGM around $600.
• AGM soap-box - Consider a LiFePO4 using full 100% discharge will last 300 cycles and an AGM must only be dropped 40% to get the same number of cycles, you can easily see that Lithium is far cheaper in the long run! Let's calculate: To get the 300 cycles of 270 Ah, I'd need almost 7 AGM batteries... $4200 and 800 lbs.
• When lithium batteries die (way down the road) it tends to be just one cell that goes bad. If I build them, I'll know how to check and replace that one cell. As originally mentioned. I expect these to be of use to my descendants.

Before I ramble too far (to late) lets get back to actually answering your question - It's my current understanding that the BMS (#4 above) will supply all the information I can ever need in a system via an app for iPhone, Android and/or PC. That is what I intend to use for battery monitoring on the boat. The BMS is rated up to 120 Amps (IN or OUT). That is where I sized the 1500W inverter. Steve at Overkill Solar assures me that the BMS will easily handle the Inverter's 3000 surge watts.

For LiFePO4 chemistry 100% is at 3.65V per cell. I will be building a 12V nominal system and for 4 cells, full voltage will be 14.4V. I am currently researching reducing that peak voltage. There are some references that indicate that thousands of battery cycles is achievable if capacity is cycled between say... 20% and 90%.

Back to the testing aspect - The battery monitor is for testing. Typically, LiFePO4 batteries are rated for discharge at 0.1C. That means you take the rated capacity in Ahr and multiply by 0.1 and that gives you the rate of output that SHOULD achieve the rated capacity. For my 4 cell battery that capacity is 270 Ahr. So... for discharge testing, I'll be running them through this battery monitor at 27 Amps.

[Inquisitor]

This is just a cluttered snapshot of my brain.

ITEMS

1. Solar Panels (2) 100W, 12V Nominal - What you get at high noon in the Caribbean. Anywhere else, at any other time and depending on what load is being required, the voltage varies from 0 to 22.6V and the current varies from 0 to 5.86A. I will be placing them in series for 24V nominal. These will be placed on an arch over the transom, with the panels hanging back over the motor. The arch is currently project MX-9.
2. Charge Controller - This takes the wildly changing output of the panels and converts it to a voltage that the battery likes for charging. Some controllers only work to downgrade voltage (ie. 24V down to 14.4V) meaning they crap-out when the voltage falls below battery voltage. This controller also boosts voltages from 0 to 14.4 up to the 14.4 required. Thus it will start charging earlier in the day and later into the afternoon than other chargers and is less susceptible to partial shading. This will be placed in the M's battery compartment if possible.
3. BMS - Battery Management System - This make sure the individual cells are treated properly. Although the battery cells are capable of charging at 270 Amps and discharging at 540 Amps, the BMS limits both to 120 Amps. It also charges the individual cells to keep things all balanced between cells and checks for minimum and maximum temperatures. This will be placed inside the battery cells case.
4. LiFePO4 battery cells. 4 Cells with a maximum nominal charge of 3.65V and 270A. This will be placed inside the battery cells case and placed in the M's battery compartment if possible.
5. Inverter 1500W maximum / 3000W surge - Has display for status, GFCI and a remote switch so electricity is not wasted when not in use.
6. TBD fuse or circuit breaker panel.
7. Separate circuits for:
   • Fridge
   • Fresh water pump
   • Bilge pump
   • Wash-down pump
   • Lighting
   • USB Ports for phones, tablets
   • Radar, Sonar, Chart Plotter, Autopilot
   • TBD - Other things

CONNECTIONS

1. TBD - About 20' worth of wire with special connectors that the panel uses to run from arch to under M's steps.
2. TBD - Short run of less than 2' with in-line 20 Amp fuse. Fuse will likely be integrated into the battery box.
3. Wiring included with BMS that bolts directly to the cells posts all within the battery case.
4. TBD - Multiple positive terminal connection points built into the battery case.
5. TBD - Short run to inverter with in-line ~150 Amp fuse. Fuse will likely be integrated into the battery box.
6. TBD - Likely to run AC lines from Inverter to a couple of places in the boat.
7. TBD - Short run to fuse/circuit breaker panel with in-line master fuse.
8. TBD - Runs and fuse sizing as necessary

NOT SHOWN

• Motor cables, standard deep-cycle starter battery inside the M's battery compartment.
• TBD - Perko switch. May permit switching over/combining batteries. Haven't determined if its a good idea yet. Can't pull more than 120Amps so it can't start the motor, and its not a good idea to charge LiFePO4 batteries from the alternator without other significant hardware.
• TBD - Electrical converter to trickle charge the starter battery from the house system if the engine isn't run for long periods - https://www.amazon.com/Converter-13-8V- ... B07X9Y5MXT

[Inquisitor]

I know you're all just waiting with baited breath.

• (4) 272Ah Battery Cells $450 - The China cells are having trouble getting across the pond. I do have a tracking number and they're on the way. Apparently shipping containers are in short supply and being used for storage around the world. Delays are expected.
  
• Solar Panel extension cables $27 - These will route the electricity from the solar panels somewhere on the aft arch (TBD) down to the charge controller that will be placed somewhere near the M's battery compartment. (TBD) https://www.amazon.com/gp/product/B08K4SFWV4/
  

I've started researching, purchasing and testing various things that all this electricity will be used. Depending on how much data I generate, I'll either add it in this thread or create a thread just for it.

• Aspenora 54 quart Fridge / Freezer $363 - Extensive testing going on here:
  viewtopic.php?f=8&t=28046
  
• 300 watt Giandel pure sine wave inverter $48 - After quite a bit of research, I found that the large (1500+ watt) power supplies have pretty bad efficiencies when running at low wattages. In my use case for the Mac, I'll be driving most electrical things with 12VDC.
  • LED lighting
  • Marine electronics - Chart plotter, autopilot, radios, maybe radar and sonar some day.
  • USB chargers for phones and tablets, Bluetooth stereo speakers, etc.
  As for 120 VAC, I will have one class of items that will be short term, but high wattage items. For these, I'll need the 1500+ watt Inverter.
  • Power tools
  • Shop vac
  • Blender
  • Microwave - Because I will have such a large capacity system (4 kWh) I'm starting to look into getting rid of the propane stove inside and substituting a Microwave oven. Will report back.
  A second class of items, have low wattage. It is this second group, I have purchased this small inverter. Based on some test data, the large inverters are only 75% efficient when running sub 100 watt items, while this 300 watt inverter is supposedly 95% efficient. This indicates nearly a 30% longer run time than running these devices off the large inverter. Will report back once I've tested things.
  • Laptop
  • Large screen LCD/LED TV - This will be a Roku TV connected to a Raspberry Pi hosting PLEX to stream a movie library AND to act as the monitor for the computer running chart planning, boat system status information and other programs.
  https://www.amazon.com/gp/product/B07SLPWBK3
  

Current Expenditures for the Electrifying Project

[chipveres]

I think (I'm not sure) that the BMS needs to be connected to each individual cell in case it has to cut one out.

Chip V.
s/v Sand Dollar

[Inquisitor]

I think (I'm not sure) that the BMS needs to be connected to each individual cell in case it has to cut one out.

Chip V.
s/v Sand Dollar

You are correct in the general case. These days, there is a huge market and they come in all kinds of flavors. Many are designed to be connected to just one cell... and will protect it from undercharge, overcharge, overcurrent including shorts and over heating. Others, like the one I'm using is a four-cell version. For all the protect modes, it will cut out the entire battery (4 cells) in one direction or the other. Besides connecting to the series to supply 12VDC, it also has leads going to each cell to facilitate balancing the cells to improve longevity. It also limits the maximum current to 120 amps. It has an additional feature of keeping from charging the cells in cold temperatures. LiFePO4 cells are damaged if charged under 32F. This one also has a Bluetooth interface and an iPhone / Android app to monitor SOC, Current, Voltage cell balance and temperature and more.

Basically, beside protecting the battery, it'll give me all the data of a battery monitor. How much do those typically run for lead-acid?

[Starscream]

Ok, it's official. I'm changing my pre-conceived notions about people who live in the hills of North Carolina (JimmyT already forced me to do the same thing about Alabamians).

I'm an engineer but I'm not smart enough to make a meaningful contribution to THIS thread.



***Internet disclaimer: The opinions stated in this post are meant to be humorous and taken in good nature. I pre-apologize to anyone who may be offended by the stereotypical view of North Carolinians and Alabamians presented herein. Those views are in jest.

[Inquisitor]

Ok, it's official. I'm changing my pre-conceived notions about people who live in the hills of North Carolina (JimmyT already forced me to do the same thing about Alabamians).

- We talk slow because its hot, not because we're add'ld... well... most of us.
We UT people are not sure about Bama folk though... especially during football season. But, I'm thinking JimmyT's a transplant.

I got one of my degrees up north. The engineering was easy... translating the northern dialect was the toughest part. Once I figured, I could record it and play it back at half speed... I was good to go.

[chipveres]

I think (I'm not sure) that the BMS needs to be connected to each individual cell in case it has to cut one out.

Chip V.
s/v Sand Dollar

You are correct in the general case. These days, there is a huge market and they come in all kinds of flavors. Many are designed to be connected to just one cell... and will protect it from undercharge, overcharge, overcurrent including shorts and over heating. Others, like the one I'm using is a four-cell version. For all the protect modes, it will cut out the entire battery (4 cells) in one direction or the other. Besides connecting to the series to supply 12VDC, it also has leads going to each cell to facilitate balancing the cells to improve longevity. It also limits the maximum current to 120 amps. It has an additional feature of keeping from charging the cells in cold temperatures. LiFePO4 cells are damaged if charged under 32F. This one also has a Bluetooth interface and an iPhone / Android app to monitor SOC, Current, Voltage cell balance and temperature and more.

Basically, beside protecting the battery, it'll give me all the data of a battery monitor. How much do those typically run for lead-acid?

Thank you. I learned from this.
Chip V.

[Jimmyt]

Ok, it's official. I'm changing my pre-conceived notions about people who live in the hills of North Carolina (JimmyT already forced me to do the same thing about Alabamians).

- We talk slow because its hot, not because we're add'ld... well... most of us.
We UT people are not sure about Bama folk though... especially during football season. But, I'm thinking JimmyT's a transplant.

I got one of my degrees up north. The engineering was easy... translating the northern dialect was the toughest part. Once I figured, I could record it and play it back at half speed... I was good to go.

I guess you have to talk fast so your tongue doesn't freeze to the roof of your mouth. Down here, we don't want to move faster than necessary to avoid creating more heat.

Born and raised in Mobile AL. ME from Auburn University '81. Mom got her Masters at 'Bama. Dad got his ME at Auburn. The Alabama Auburn game days were tough times at our house... I never developed a strong love of the game for some reason.

[Inquisitor]

Born and raised in Mobile AL. ME from Auburn University '81.

Ahhhh... the Think Tank of Alabama. I detected some serious engineering behind that galley project.