Inqism-03: Electrifying

[Russ]

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.

My business partner lives in Mobile and played for Auburn in the late 80s and was drafted by Green Bay and played until he got injured.

He tells of the rivalry between Auburn and Alabama. These rivalries between local teams are always interesting.

[Inquisitor]

Got the 300 watt Giandel pure sine wave inverter in and wanted to test it. The premise was that if it really got 95% efficiency running low wattage items (< 100w) I could justify having this for small loads and a 1500 watt Inverter for the short deration/high wattage items.


The test uses...

• the old, beat up deep-cycle battery from viewtopic.php?f=7&t=28031&start=75#p346892
• running through the capacity tester from viewtopic.php?f=8&t=28020#p346304 to measure DC watt hours drawn from the battery
• through the Giandel Inverter
• through the Wemo Insight Smart Plug to measure AC watt hours used.
• To a load using several light bulbs

The Wemo Insight is a marginally accurate device which fluctuates quite a bit. Instead of trying to get an instantaneous reading I ran the tests over many hours so that those numbers can be averaged using the watt-hours tallied over the runtime of the test. Makes for a far more accurate test. Also... the Wemo draws some power to report and Bluetooth that information to the Android app. In a separate test, I determined its usage rate at 1.78 watts.

Results

1. At 71 watts load, I measure 85.2% efficiency. IOW, it uses 83.3 watts from the battery.
2. 144 watts, 85.9%
3. 279 watts, 90.5%

Summary

• From reading about Inverters, they tend to be more efficient at their rated capacity. This one also followed that trend. The lowest wattage efficiency was disappointing... in that marketing literature says "up to" 95% efficient. I was counting on a relative high efficiency at sub 100w rates to justify having two inverters. I will know better once I test these numbers against the 1500 watt Inverter.
• The good aspect, the Inverter was dead quite below 100 watt usage. The fan does not come on till over 100watts. It uses passive cooling. The case leveled out at 95°F.
• Above, 100 watts, the fan comes on and eats into the Inverter's efficiency. The fan is not loud, but I really don't have another Inverter to compare. I'd say its about as quiet as a desktop power supply fan. The case temperature drops to 78°F once the fan is going.

[Jimmyt]

This is fantastic information! I would have guessed the device would be better at the low end of its capacity. Guess I should have taken a few more EE classes.

[Jimmyt]

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.

My business partner lives in Mobile and played for Auburn in the late 80s and was drafted by Green Bay and played until he got injured.

He tells of the rivalry between Auburn and Alabama. These rivalries between local teams are always interesting.

It can get pretty dicey, depending on the company you keep. Had a couple of co-workers that started pranking each other over the game. Got worse with every iteration until they were about to come to blows over the whole business. These were freakin professional engineers...

I guess we all are passionate about something. I just don't feel it about football. Could be the fact that growing up; Saturday consisted of three televisions with different games on (volume off), and a radio of either one of the three on tv or a fourth game. Many a beautiful day wasted. I can enjoy watching a game with family or friends, but I'm not going to fight anyone over the outcome.

[Inquisitor]

This is fantastic information! I would have guessed the device would be better at the low end of its capacity. Guess I should have taken a few more EE classes.

The other forum, where I'm learning about all this off-grid powering, there were threads discussing being efficient at the top, but not the low end. It got me thinking about the wasted energy of a big inverter. Most of those members don't care since they over built. Filling a roof with solar panels is no big deal. I ran the numbers using marketing data efficiencies and found that I could run a laptop 30% longer on this little inverter versus the big one. That was enough for me to buy this one to test the theory. I put the results on that site as well and commented that this unit was not living up to its marketing data of 95% efficient. A response said,

"If it makes you feel any better, my $2000 Victron 48/5kW is about 65% efficient at 71W."

You'd think that these high-end Inverters would handle this better... even if it was two separate sets of electronics inside and some switching mechanism as the power usage went up. But like you... I only had one required EE class. Irrational Math is my brick wall! Just couldn't wrap my head around it.

[Inquisitor]

My first hastily run, impromptu test with the solar panels. Conditions:

• (2) 100 w panels set up in series.
• It was a clear sunny day.
• The panels were aimed pretty well.
• Time of season is near winter solstice.
• The sun was trivially shaded by limbs at the top of bare 100' Poplars.

Even with all the handicaps, they reached a peak of 154 watts.
From 2:30 to 4:30, they added a total of 108 watt-hours to the battery.

This image was taken when a large spruce tree was 100% shading one panel and 50% shading another. Here, it was outputting a mere 3 watts.



My pre-conceived notions about solar-panels was the latitude difference between NC and say the Bahama's alone would knock them down 50%. So I'm encouraged these will serve well.

[Ixneigh]

The idea of making ones own battery is interesting to me. I would like to eventually go to a lithium system. It’s lighter. I could make the batter in a different shape perhaps. I could locate them elsewhere than in a damp hard to access compartment. No venting needed. I’ll be following this thread for sure.

Ix

[Inquisitor]

The idea of making ones own battery is interesting to me. I would like to eventually go to a lithium system. It’s lighter. I could make the batter in a different shape perhaps. I could locate them elsewhere than in a damp hard to access compartment. No venting needed. I’ll be following this thread for sure.

Ix

Thank you for your kind words. Its nice to get recognized by the Admirals.

I had similar thoughts about combining in different geometry. I "believe" I can get the common configuration of cells (in a DIY case) next to my old type 24 battery that I'll keep just to start the motor. viewtopic.php?f=7&t=28031&p=346946#p346943

But... I also considered that I might put them side by side long-ways and place them under the steps in front of the other two standard shaped batteries. There is cavernous volume between the batteries and the wall that the steps mount. But hopefully 270 Ah will be "enough".

Here's the drawing for the ones I'll be using... if you're interested. I was originally going to get the 100 Ah cells, but these in the 270-280Ah range were only about 20% more delivered. I read somewhere that the reason these are so relatively cheap, is China's own electric bus/car/motorcycle industries use these and they make tons. Also the issue... half the delivered price is shipping.

[Ixneigh]

Cool. I guess the EV revolution will benefit us on sailing vessels also. At least those of us on small solar or wind systems. Maybe a solar panel battery combination will become more economical in a few years.
Ix

[Jimmyt]

Thanks for posting that. To recap, your 200 watts of panel put about 54 watts avg into the batteries when you aimed them as best you could (for your 2 hour period). Ergo, you aren't likely to get rated output on your boat while sailing. And, unless you have the panels on a two-axis mount, even in a calm anchorage you won't get rated output. Shading is a killer. Great stuff to know.

[Inquisitor]

Thanks for posting that. To recap, your 200 watts of panel put about 54 watts avg into the batteries when you aimed them as best you could (for your 2 hour period). Ergo, you aren't likely to get rated output on your boat while sailing. And, unless you have the panels on a two-axis mount, even in a calm anchorage you won't get rated output. Shading is a killer. Great stuff to know.

Yes to all you said. However, it was a half-ass test. Clouds just cleared out and I rushed outside to setup all the gear... I was just using lamp cord, and everything was held on by friction and I looked up and the sun was filtering through the treetops and sometimes larger trunks. I couldn't really move them without losing connections and restarting the test. Also, we live in a cove, so don't see the sun for that long during the winter.

I've also seen tests on the other forum that shading screws up the output. It is not linear proportional to the amount of area unshaded like I would have guessed. I want go WAG that a boom width stripe across will cut 80% off. So like... putting them on top of the sliding hatch is almost a waste of money. BUT...

I will set up some tests that are more to our situation. Try to find a more open field with no trees.

1. Lay them flat and do the full day's arc. Maybe adjust the angle so its at least a summer angle in Florida.
2. Also cast a boom shadow over one and both and get real time drops to see for sure.

Unfortunately, according to our weather predictions, we won't see the sun for the next seven days. Stay tuned.

[OverEasy]

Wow! This is a lot more involved than it first looks Inqism-03!

Please understand I’m not really up to speed on all this as you are.
You have put in a lot of work and time getting all this together.

The battery choice seems to be involved. The build vs. Weight vs. cost aspect has me a little confused.
It appears that the charge controller for four cells is built in the prefab cell pack as well as a casing, wiring and connections.
I’m curious about the all up weight aspect for the system being fabricated vs. the prefab system.
Have you figured out what the final weight difference is?

The DIY aspect is great and I well appreciate the sense of satisfaction of creating something for one’s self.
Have you an estimate of the time expended to create the battery fabrication your making?

I like what you have created so far and look forward to following your progress.

[Inquisitor]

Beware what you ask...
... but do ask. It makes this Covid winter more tolerable.
Thanks

Wow! This is a lot more involved than it first looks Inqism-03!

Please understand I’m not really up to speed on all this as you are.
You have put in a lot of work and time getting all this together.

The battery choice seems to be involved. The build vs. Weight vs. cost aspect has me a little confused.
It appears that the charge controller for four cells is built in the prefab cell pack as well as a casing, wiring and connections.
I’m curious about the all up weight aspect for the system being fabricated vs. the prefab system.
Have you figured out what the final weight difference is?

The DIY aspect is great and I well appreciate the sense of satisfaction of creating something for one’s self.
Have you an estimate of the time expended to create the battery fabrication your making?

I like what you have created so far and look forward to following your progress.

That is a great question and one that I "felt" might be an issue. This third project in my 's refurbishment/rebuild (Inqism-03) is about the total re-electrification of the boat. I didn't do a really good job on an overview and it has a lot of pieces, but it's pretty strait forward. I will do a better job of breaking it up into sections. It will include electric generation (solar), battery charging, the battery, DC circuits, outlets and devices, power Inverters, AC circuits and AC devices. I am not an EE or technician, but just an avid DIYer. Much of the information I am learning from an electric off-grid forum and sharing with this forum. I ask just as many questions there as I do here. So I search and if not satisfied, I post questions and pull the information out of experts or confirm my assumptions on that site before blathering them here. So far in this thread, I have ONLY started gathering the pieces.

When I do some testing on a component of this project, and it is pretty simple I will add it to this topic, like:

• the 300 watt inverter viewtopic.php?f=8&t=28020&p=347109&hili ... er#p347109.

If it is an extensive build or testing, I'll add it as a new topic under Repairs and Modification

• Refrigerator - viewtopic.php?f=8&t=28046
• Microwave - viewtopic.php?f=8&t=28102

I will definitely splinter out the battery build.

When I first pulled the Mac out of my father-in-laws field (3+ years sitting), it had two Walmart/Auto store level of deep-cycle batteries. One was dead as a hammer. The other still had a significant charge on it! Wow... no charging, no solar no nothing and kept charge for 3+ years. That is the battery I got advice for and tested in viewtopic.php?f=7&t=28031. CCA were still their, but capacity is down about half of original. I'll be using it for my boat motor starter battery.

Now to answer your specific questions about the battery. The answers can be involved, because it "depends" on how you want to look at it. Some might want to compare to what they have now. Others might want to see based on total life ownership. Others, might most bang for the buck. I'll try to hit all three.

My Time
Research - If you count research time, asking questions on the other forum, I've probably spent over 50 hours. Would someone else on this forum need to put that much time in? Depends on how much, you trust what I've done... or if you go for an off the shelf solution, how much time you typically invest in researching a product. Would I do it when I could be sailing... the answer would be Nooooo.

Ordering - Once decided in the research, ten minutes.

Waiting - I have not started the battery build. If you want to source a turnkey solution or even source parts here, it'll take the normal shipping times. Doing it as cheap as I am able and with a lot of support from the other off-grid forum, I am taking a stab at sourcing the cells directly from China. They are literally on the slow-boat from China. World events (shortage of shipping containers) have at least doubled the time to delivery. People on that site who ordered their batteries in mid October, got theirs in mid November. Those of us that started orders in mid November or later are just now starting to get their shipments. I ordered November 29 and am waiting still. I am hopefully... close.

Build - I will be doing extra testing to satisfy my curiosity about things. I also plan to design and 3D print parts to act as insulation and/or mounting points for some parts. I will also incorporate fuses for the main inputs/outputs to the battery as part of the battery case. On the other forum, they just screw these parts to a piece of plywood and don't really care how much room they take. If someone else on this forum decides to go for LiFePO4 batteries, they can spend:

• zero time - Just order a battery from BattleBorn and away you go. There are some other important considerations, so it can't be just substituted for lead-acid batteries. I'll discuss those as the project proceeds. It'll last longer on a charge AND several AGM replacements lifetimes over.
• 4 hours - Assembly is trivial. I'd say less than an hour for someone on their first time and doesn't get the shakes when a box is labeled, "Some assembly required". The other three hours is to do what I would consider to be the minimal amount of testing just to validate the cells. BattleBorn has supposedly done at least these tests. This does not include actual charge/discharge time. I don't watch grass grow, I'm not going to watch a battery charge. That might take days. Its a really BIG battery!
• 40+ hours - Just me! I want to know stuff. You all will get that stuff without having to do it. I want to make my own battery case out of fiberglass and wood. You can purchase a plastic case for ~$10. I want to design, CAD and 3D print components. You can tape things together. When doing the build, I'll try to isolate what are minimal and what are me being an anal-retentive engineer.

In all the following comparisons, LiFePO4 will far surpass high-quality AGMs on every metric.
Even price, if you are willing to DIY it. Before I do all the comparisons, you have to understand two very important factors before you can compare them. You can discharge (use) a LiFePO4 battery far deeper than an AGM battery and life expectancy is heavily based on how deeply you discharge the battery.

• Recommended discharge for AGM is 50% of capacity. If cuddled, and checked periodically it will last 1200 cycles. ref: http://www.trojanbattery.com/pdf/Signat ... eSheet.pdf
• Recommended discharge for LiFePO4 is 80% of capacity. No cuddling necessary. Will last 5000 cycles. ref: https://www.super-b.com/en/lithium-iron ... -batteries
• Another site indicates for LiFePO4 can be used 100% capacity and still get 3000 cycles

Thus, you can limit yourself to 80% and get 5000 cycles like off-grid people do... or get twice the capacity AND 2.5 times the life of high quality AGM.

Compare on Weight
Different ways of comparing:

• LiFePO4, 100 Ah (100 usable) battery like a BattleBorn is 31 lbs.
• Lead-acid, 100 Ah (50 usable) deep-cycle is 45 lbs. - Do you count needing two lead-acid to compare capacity or live with 50% less capacity.
• LiFePO4, 272 Ah (272 usable) like I'm going to build should weigh about 60 lbs.
• Lead-acid, 260 Ah usable using (2) Trojan 6V T-145 batteries (to make 12V) weighs 144 lbs.

Compare on Price
This is harder to compare since some people don't need much power and are quite happy with a Walmart deep-cycle battery at less than $100. Other will go top level AGM. And even that, I can't find a reliable price. On Amazon, (2) T-105s with shipping will set you back $840. But if you lived in a big city, you might avoid $300 of that right away due to shipping. Others on this forum have pointed out other 6 volt, golf-cart batteries that were around $300 before shipping. So... you have to compare the lead-acid side of your choice.

• BattleBorn 100 Ah delivered $900
• The one I will be building, 272 Ah delivered (by slow boat) $600

But, remember, LiFePO4 will last at least 2.5 times AGM! And if you discharge the LFP batteries to 80%, you'll need more than FOUR complete sets of AGM!

I think I've worn this subject out. If something doesn't make sense, just ask.

[Inquisitor]

For anyone seriously interested, here is a great article. It sums up the pros and cons of using Lithium batteries in a boat. Although he is a huge proponent, he would almost dissuade you. It is a very long read and most of the first part explains technically what needs to happen with LFP vs Lead-Acid. You might give up, thinking this is too big of a PITA. But about half way through, he finally get to the BMS which does most all of this work for you.

It also clearly (and technically) explains why you can't just replace a lead-battery... when it comes to your alternator and any critical systems.
https://marinehowto.com/lifepo4-batteries-on-boats/

[Starscream]

After reading that link, ima stick to my agm until a true drop-in LFP battery becomes available for $400 or less and can crank my engine and accept full amps from the alternator.

I'm generally an early adopter, but considering the way we use our Mac, I'm good with the status quo for a while.

But the link made me even more impressed that you're gonna take this on. I'll stick to sewing for now.


PS i have a buddy who performs songs about sewing. He's a Singer-songwriter, or sew it seams.