LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

[goboatingnow]

Originally Posted by PaulCrawhorn

600W is power capacity, no mention of energy.

Is that really used here as a battery spec? If so pretty irrelevant...

As the ad says , “must visit specsavers “

[newhaul]

Originally Posted by s/v Jedi

The document is actually good and states 600Wh… I have given up telling people that W is for power and Wh is for energy; they just don’t get it

Yep you me and StuM . 600Wh at 12v is 50ah .
At 24v it's 25ah . They m8ght understand it now .

[wholybee]

Originally Posted by CharlieJ

For all of you postulating that E-13 should have been only limited to LFP, Torqeedo, a company with thousands of lithium based batteries in the wild, uses NMC technology. To specify LFP only would have left their installations with not even the minimal coverage given by TE-13/E-13.
<snip>

Exactly. The document was written to not harm member manufactures.

[hjohnson]

Originally Posted by CharlieJ

For all of you postulating that E-13 should have been only limited to LFP, Torqeedo, a company with thousands of lithium based batteries in the wild, uses NMC technology. To specify LFP only would have left their installations with not even the minimal coverage given by TE-13/E-13.

My point was more that there should have been different treatment between the various chemistries. Having built one myself, I’m pretty comfortable with DIY LiFePO4 batteries, but wouldn’t trust myself with NMC pouches and the like at this scale.

[goboatingnow]

Originally Posted by hjohnson

My point was more that there should have been different treatment between the various chemistries. Having built one myself, I’m pretty comfortable with DIY LiFePO4 batteries, but wouldn’t trust myself with NMC pouches and the like at this scale.

Correct. In fact E-13 will further convince insurers that LFP is conflated with other volatile Li chemistries and that your boat will burst into flames at any minute.

It’s a travesty of a document as it makes no attempt to differentiate the chemistries.

[wholybee]

Originally Posted by goboatingnow

Correct. In fact E-13 will further convince insurers that LFP is conflated with other volatile Li chemistries and that your boat will burst into flames at any minute.

It’s a travesty of a document as it makes no attempt to differentiate the chemistries.

Which will be even worse when an ABYC compliant boat burns and someone dies.

[s/v Jedi]

About refrigeration: I have energy consumption numbers for the Snomaster Expedition Series EX95 fridge/freezer used as a freezer. You can put a hefty amount of food in these units, see attached picture. (https://www.snomasterusa.com/product...fridgefreezer/)

These are numbers from actual testing that I did a while ago. Numbers are in kWh for a 24h period and at a thermostat setting as shown:

0F: 960Wh/day energy consumption at 57% duty cycle
3F: 850Wh/day energy consumption at 48% duty cycle
6F: 760Wh/day energy consumption at 42% duty cycle

[newhaul]

Originally Posted by s/v Jedi

About refrigeration: I have energy consumption numbers for the Snomaster Expedition Series EX95 fridge/freezer used as a freezer. You can put a hefty amount of food in these units, see attached picture. (https://www.snomasterusa.com/product...fridgefreezer/)

These are numbers from actual testing that I did a while ago. Numbers are in kWh for a 24h period and at a thermostat setting as shown:

0F: 960Wh/day energy consumption at 57% duty cycle
3F: 850Wh/day energy consumption at 48% duty cycle
6F: 760Wh/day energy consumption at 42% duty cycle

Thanks for posting . Those numbers are kinda scarry to me at 0°F that works out to 75ah for me . I only have 200 watts solar so it would take everything to run it . But I'm also only 29 ft x 8ft.

[mitiempo]

Originally Posted by newhaul

Thanks for posting . Those numbers are kinda scarry to me at 0°F that works out to 75ah for me . I only have 200 watts solar so it would take everything to run it . But I'm also only 29 ft x 8ft.

Look at Engel - they use a lot less power.

[goboatingnow]

Originally Posted by newhaul

Thanks for posting . Those numbers are kinda scarry to me at 0°F that works out to 75ah for me . I only have 200 watts solar so it would take everything to run it . But I'm also only 29 ft x 8ft.

A freezer is rather impractical in your case. Dometics prepackaged freezers are typically about 60 Ah over 24 hours.

[s/v Jedi]

Originally Posted by newhaul

Thanks for posting . Those numbers are kinda scarry to me at 0°F that works out to 75ah for me . I only have 200 watts solar so it would take everything to run it . But I'm also only 29 ft x 8ft.

This is a 95 liter freezer, which is very large. You must measure your box and adjust for volume.

Originally Posted by mitiempo

Look at Engel - they use a lot less power.

Why do you think that? The Snomaster boxes have an extra inch of insulation so they use much less power than an Engel. Also, the Snomaster is constructed from stainless steel while Engel is not.

There is a difference in compressors: the Snomaster has a bigger compressor, so more powerful but at higher running amperage at high speed mode. This is good. The Engel compressor probably has a longer lifespan as it is a simpler design with less moving parts.

Originally Posted by goboatingnow

A freezer is rather impractical in your case. Dometics prepackaged freezers are typically about 60 Ah over 24 hours.

These boxes have less insulation but it is very high quality, plus they have magnetic seals. You will find better performance over the lifespan of the system. I think you’re talking about the portable Dometic boxes just like the Snomaster? I have one of those as well and it uses much more energy than a Snomaster box.

[newhaul]

Originally Posted by mitiempo

Look at Engel - they use a lot less power.

Actually I just purchased a used cool blue holding plate system and converted my ice box to refer. Hope to get installed by Christmas.
The conversion is on my refit page . I have from 2 to 4 inches of cryogel-z ( R8 per 10mm )
Have even more between outside of the box and the hull. Just threw all the scraps back there . Used about 35ah per 24 in the 2cf freezer and 4 cf fridge install on my spencer .
This install will be 2 cf and 3 cf spill system as well.

[newhaul]

Originally Posted by goboatingnow

A freezer is rather impractical in your case. Dometics prepackaged freezers are typically about 60 Ah over 24 hours.

Freezer is necessary for me as an average yellow fin or Bonito is to much for me to eat with just refrigeration.

See above

[goboatingnow]

Originally Posted by newhaul

Freezer is necessary for me as an average yellow fin or Bonito is to much for me to eat with just refrigeration.



See above

Then it’s the case you’ll need to add lots of solar and batteries to match or eat less fish !!

[newhaul]

Originally Posted by goboatingnow

Then it’s the case you’ll need to add lots of solar and batteries to match or eat less fish !!

I'm doing just fine . had 200 watts and 440ah Fla on the spencer and did just fine now I have 200 an mppt and 250 lfp. So far my non refer use average is under 20ah a day .

And don't ya mean eat more fish ? Would leave less to store