LiFePO4 Lithium Battery Vs AGM for House Bank "Pros" and "Cons"

Poey50 said:
I'm a bit puzzled as to who is making it sound impossible but, leaving that aside, I think its possible to make a good argument that the most cost-effective and suitable systems for boats are DIY builds. Expensive integrated systems like those of Victron are fabulous but there is a danger that those buying the system and the installation haven't educated themselves sufficiently, but have just thrown money. Fine until things go wrong. Worst of all, I I think, are likely to be drop-in systems using cheap LFP batteries. Those are superficially the most attractive, are heavily marketed and supported by some woefully inadequate sailing magazine articles.
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Lol? poey I didnt mean you make it sound impossible,
It some of the posting I read from some actually as it happen not here on ybw .
 
Poey50 said:
I'm a bit puzzled as to who is making it sound impossible but, leaving that aside, I think its possible to make a good argument that the most cost-effective and suitable systems for boats are DIY builds. Expensive integrated systems like those of Victron are fabulous but there is a danger that those buying the system and the installation haven't educated themselves sufficiently, but have just thrown money. Fine until things go wrong. Worst of all, I I think, are likely to be drop-in systems using cheap LFP batteries. Those are superficially the most attractive, are heavily marketed and supported by some woefully inadequate sailing magazine articles.
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I would love a Vitron setup. I think their kit is great and I love their support of Open Source. However at around £1k per battery+ lots gubbins (Battery protect) it starts to get very expensive!

Maybe if I win the lottery I can get a Boreal with blue stuff inside :-)

On a minor point, Victron default LifePO4 profiles charge to 14.1V (3.525 per cell) which allot of people consider is "high". I assume they do that to get to a point that balancing kicks in.

I have not seen those sorts of magazine articles.
 
And here's a typical terrible advert for LFP. This one annoyed me so much I wrote and complained to SVB. The reply was clueless.

Lithium Battery 12 V / 100 Ah buy now | SVB

Anyone buying it as a replacement drop-in battery as advertised and charging at those rates will very soon have their first high voltage disconnect when motoring. The voltage transient will take out their alternator regulator. If marine electronics are on the same circuit then those can also get fried. And if the boat is crossing a busy shipping lane at night when the battery goes into a non-communicative stage then ....

If there are sufficient loads to keep the voltage just under the level of high voltage disconnect (which may be fixed at a high level) then the continuously full battery at that high float will progressively lose capacity.

But ...it looks like a battery and it's lithium so ... cool!
 
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Poey50 said:
And here's a typical terrible advert for LFP. This one annoyed me so much I wrote and complained to SVB. The reply was clueless.

Lithium Battery 12 V / 100 Ah buy now | SVB

Anyone buying it as a replacement drop-in battery as advertised and charging at those rates will very soon have their first high voltage disconnect when motoring. The voltage transient will take out their alternator regulator. If marine electronics are on the same circuit then those can also get fried. And if the boat is crossing a busy shipping lane at night when the battery goes into a non-communicative stage then ....

If there are sufficient loads to keep the voltage just under the level of high voltage disconnect (which may be fixed at a high level) then the continuously full battery at that high float will progressively lose capacity.

But ...it looks like a battery and it's lithium so ... cool!
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I don't disagree.

Thinking about it; Dropping these into our, or any 3xft sailing yacht and doing a motored channel or other motored crossing (e.g 10hrs) and your are likely to hit the high voltage disconnect. Lets say 50A from the alternator at fullish output for only a few hours will likely take the 100Ah batteries from empty to full and disconnect levels.

If my maths if vaguely right, we should be seeing more to allot of those sorts of events post covid issues.
 
gregcope said:
I don't disagree.

Thinking about it; Dropping these into our, or any 3xft sailing yacht and doing a motored channel or other motored crossing (e.g 10hrs) and your are likely to hit the high voltage disconnect. Lets say 50A from the alternator at fullish output for only a few hours will likely take the 100Ah batteries from empty to full and disconnect levels.

If my maths if vaguely right, we should be seeing more to allot of those sorts of events post covid issues.
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This is a common US experience according to Rod Collins. Those buying LFP drop-ins are all up and loud on social media. When they go wrong they slip quietly into his marine electrical business with depleted drop-ins and melted alternators. "But Rod, the adverts made it sound so easy!"
 
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