Low Budget Lifepo4 Experiences anyone?

[Dave9111]

Originally Posted by newhaul

Actually Adele made the chart for us and I'm assuming all are published specs yes

I do know the specs and real word for my lfp cells . well above specs and I fully expect over 10k cycles due to my light usage of them . rarely use more than a 30% dod. Ie between 95% charge and 70% charge with max of .3C charge and even lower discharge rates

Thanks Newhaul,

10,000 cycles is a bit over 27 years if you do one cycle per day.

That seems like a dream at best. If I bought a new diesel engine for my boat and said I expect it to be alive and functional in 27 years, what would you think?

No one knows.

Heck, the chances of me being alive in 27 years is highly questionable!



That's why I was surprised to see the Trojan Carbon battery come up with such good specs in that chart. Trojan has a very long history. They do a lot of testing. I suspect some Trojan batteries are in my future.


Dave

[Adelie]

Dave9111:
Where are you? If in SoCal I’ll tell you where I got the battery prices for the T-1275s and the SPRE 06 255, I bought 1275s for my boat at that price and they have the SPREs.

I would suggest updating your profile with your general location and your boat make & model or “Looking” in the "Boat" category. This info shows up under your UserName in every post in the web view. Many questions are boat and/or location dependent and having these tidbits under your UserName saves answering those questions repeatedly. If you need help setting up your profile then click on this link: https://www.cruisersforum.com/forums...ml#post3308797

I would happily help more if the link above is not enough.

[newhaul]

Originally Posted by Dave9111

Thanks Newhaul,

10,000 cycles is a bit over 27 years if you do one cycle per day.

That seems like a dream at best. If I bought a new diesel engine for my boat and said I expect it to be alive and functional in 27 years, what would you think?

No one knows.

Heck, the chances of me being alive in 27 years is highly questionable!



That's why I was surprised to see the Trojan Carbon battery come up with such good specs in that chart. Trojan has a very long history. They do a lot of testing. I suspect some Trojan batteries are in my future.


Dave

I'm a retired shipwright I take extreme care of my systems . the westerbeke I'm putting in is 35 years old now and I expect at least another 20 before I rebuild . And got a good deal on that kit as well.
27 years old on a sailboat diesel could mean worn out or could mean barely broke in . I put less than 20 hours on my last boats engine annually. They are called a sailboat for a reason

[GoneDiving]

Originally Posted by Simi 60

The EVE type, with laser welded studs bought through a "trusted seller" I can get a 580ah @24v build for $3700 or a massive 840ah@ 24v for just over $5000

Where are you getting your prices from, Alibaba or AliExpress? Like for like, my cells are now A$1500 to $2000 more expensive than when I bought them just 6 months ago. And that's despite a currently pretty strong Aussie Peso.

Just a reminder that real savings can be had by waiting for the AliExpress sales. They are reasonably frequent and ~20% off isn't rare.

[Simi 60]

Originally Posted by GoneDiving

Where are you getting your prices from, Alibaba or AliExpress? Like for like, my cells are now A$1500 to $2000 more expensive than when I bought them just 6 months ago. And that's despite a currently pretty strong Aussie Peso.

Just a reminder that real savings can be had by waiting for the AliExpress sales. They are reasonably frequent and ~20% off isn't rare.

Amy Wan on Alibaba
Shenzhen Luyuan Technology Co., Ltd

https://www.google.com/search?q=amy+...e-gws-wiz-serp

[goboatingnow]

My EU solar supplier ( and winston agent ) now has own brand LiFePo4 at around $60per 100aH cell ( they price in dollars )

https://shop.gwl.eu/en/By-Brand-Manu...earchparam=EX-

I was thinking of replacing by 300aH lead acid set

What would be the equivalent Li amp hour capacity ( 200? )

I’m think of a 3P4S config to deliver 300aH with cell based BMS and passive cell balancing

I’ve just about to finish building my new Li compatible alternator controller so that needs to be installed and tested , but I’m going to do that on a bench based test rig.

[newhaul]

Originally Posted by goboatingnow

My EU solar supplier ( and winston agent ) now has own brand LiFePo4 at around $60per 100aH cell ( they price in dollars )

https://shop.gwl.eu/en/By-Brand-Manu...earchparam=EX-

I was thinking of replacing by 300aH lead acid set

What would be the equivalent Li amp hour capacity ( 200? )

I’m think of a 3P4S config to deliver 300aH with cell based BMS and passive cell balancing

I’ve just about to finish building my new Li compatible alternator controller so that needs to be installed and tested , but I’m going to do that on a bench based test rig.

300ah fla gives approx 150 usable ah so 200 lfp would give a bit more at 175 to 180 usable ah however at that price I would install an equivalent volume of lfp whatever ah that ends up being. Never heard of anybody complain about to much power available.
Just remember you need enough charging capacity to replace whatever you use .

[goboatingnow]

Originally Posted by newhaul

300ah fla gives approx 150 usable ah so 200 lfp would give a bit more at 175 to 180 usable ah however at that price I would install an equivalent volume of lfp whatever ah that ends up being. Never heard of anybody complain about to much power available.

Just remember you need enough charging capacity to replace whatever you use .

I have 400W solar , 70A Max alternator ( 40A usable ) and a small mains battery charger 10A

All are ( or will be ) Li compatible with programmed instant disconnect.

Currently the panels replace the overnight consumption by midday

[newhaul]

Originally Posted by goboatingnow

I have 400W solar , 70A Max alternator ( 40A usable ) and a small mains battery charger 10A

All are ( or will be ) Li compatible with programmed instant disconnect.

Currently the panels replace the overnight consumption by midday

Sounds good . Side question why only 60% of alternator available?
Should have up to 80 % with internal regulation when thermally throttled.

[goboatingnow]

Originally Posted by newhaul

Sounds good . Side question why only 60% of alternator available?

Should have up to 80 % with internal regulation when thermally throttled.

My tests to date suggest that with temperature rise and ambients over 40 degrees C about 40 A is the practical limit. I am looking at increased cooling so maybe will improve things.

[newhaul]

Originally Posted by goboatingnow

My tests to date suggest that with temperature rise and ambients over 40 degrees C about 40 A is the practical limit. I am looking at increased cooling so maybe will improve things.

This thread may provide some useful assistance

https://www.cruisersforum.com/forums...o4-209089.html

[goboatingnow]

Originally Posted by newhaul

This thread may provide some useful assistance



https://www.cruisersforum.com/forums...o4-209089.html

Thanks. I’m actually looking at building an external diode pack , forced air cooled this autumn. It might be a way to push more out of the alternator. ( not that I rely on it anyway )

[newhaul]

Originally Posted by goboatingnow

Thanks. I’m actually looking at building an external diode pack , forced air cooled this autumn. It might be a way to push more out of the alternator. ( not that I rely on it anyway )

In that thread we have discussed and tested several cooling options for alternators .
Worth the read

[SV THIRD DAY]

[SV THIRD DAY]

https://www.facebook.com/groups/4273...5927837497195/