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12 hours ago, Guest said:

Don't recall any of my cars having fuse in main start cable, so why have it on boat. Switching circuit does, but not heavy cable to SM.

My bmw has an explosive battery lead among other safety features.

Nope, that's not a typo! It's meant to cut power to the engine bay in event of accident to reduce fire risk....

 

Now that might be a be a bit overkill for my little boat, but at least having a starter circuit fuse probably makes sense in a lot of vessels. I've seen a few tractors and utes melt their battery leads due to things like short circuits from chafing, or even alternator issues melting cable insulation!

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12 hours ago, Island Time said:

So that is a $29 fuse that is small enough to sit on the battery terminal lug, doesn't get in the way and protects your boat from electrical clusterfucks?

Think I will get one. I was expecting something like an anchor winch isolator that needed to be mounted separately and would then need specific leads to and from it etc.

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1 hour ago, K4309 said:

So that is a $29 fuse that is small enough to sit on the battery terminal lug, doesn't get in the way and protects your boat from electrical clusterfucks?

Think I will get one. I was expecting something like an anchor winch isolator that needed to be mounted separately and would then need specific leads to and from it etc.

Thats on the start battery. On the house, as I have LifePo4, I have a class T fuse;

Class T Fuse Holder with 2 Additional Studs

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On 15/05/2024 at 2:52 PM, CarpeDiem said:

Plenty of LTO start batteries from european cars at the wreckers ;-)

 

Tried several, didn't know what I was talking about.🤔

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On 15/05/2024 at 2:52 PM, CarpeDiem said:

Plenty of LTO start batteries from european cars at the wreckers ;-)

 

Extensive check revealed none. $600 for 6x  yinlong LTO's with Balance board.

I'm told 14.2V target V will keep them to 95% SOC. (MyLiFePO4 setting) Must have weird V/SOC curve for that to happen.

Ummm, just looked -below. Make that 75%!  Don't have glowplugs, start battery is sad, weight is irrelevant, like tinkering and thinking on bailing marina.🙄

Will compensate VD to windlass. So 40Ahr will be 30 if I get house to 14.2V? Maybe not as LTO's will charge way faster?

The OCV-SOC characteristic of the LTO-based battery measured ...

 

 

The OCV-SOC characteristic of the LTO-based battery measured ...

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I wouldn't bother with a balance board.  You're not going to reach a charge point where balancing is required.

I feel quite strongly that the LFP will reach I=term long before the LTO reaches I=0A.  So you'll end up dropping the charge voltage to prevent overcharging the LFP, that will happen long before the LTO reaches equilibrium. So I believe you will need a DC/DC to top up the LTO.  Without a DC/DC I suspect that 60% SOC is more likely - BUT that would still be way more than adequate for starting purposes and you would also be able to run the windlass for quite a few ups/downs. 

It certainly intrigues me and would be a cool project I have thought about this quite a few times and if I didn't have glow plugs I would of been all in 3 years ago when I replaced my start battery :-)

Let me know if you want a second pair of hands to get in the way!

 

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Sorry mods, please delete duplicate image. Cheers.

An actual Yinlong graph below, above generic LTO. Also erroneous above as at 14.2V it will not charge any higher.  

Your post appeared as I was hitting send!  Cool, Thanks.

discharge characteristic curve

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Talking with my neighbour in the marina on Saturday and he casually mentioned he was delayed leaving for Fiji as his lithium batteries had swolllen up and he was waiting to get them looked at. He said he thought that there was no charge controller on them.   Sounds like a disaster waiting to happen so I asked him to disconnect his cables and perhaps move his boat away from mine. Perhaps I should also move mine away from his?

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1 hour ago, Addem said:

Talking with my neighbour in the marina on Saturday and he casually mentioned he was delayed leaving for Fiji as his lithium batteries had swolllen up and he was waiting to get them looked at. He said he thought that there was no charge controller on them.   Sounds like a disaster waiting to happen so I asked him to disconnect his cables and perhaps move his boat away from mine. Perhaps I should also move mine away from his?

Yep! Sounds like over charging. I've seen a couple of installs without any control in yachts that have come from offshore.:shock:. It's crazy. I re-iterate, there is, in  IMO, no such thing as a drop in lithium! And batts without BMS at all should not be used anywhere.

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