CarpeDiem 430 Posted April 14 Author Share Posted April 14 50 minutes ago, mcp said: Then custom set your absorption voltage to 13.9v. LFP must have tail current termination if the voltage is held at any value above 13.35v. 13.9v will over charge a lfp if left for long enough. The Balmar 614 allows a timeout parameter to be set on the absorbation cycle, not paying specific attention to this value could result in over charging. Without doing experiments on the actual batteries to determine a safe absorption hold timer I could never recommend a value. Hence I suggest dropping straight from bulk to hold (aka float) and skipping absorb altogether. IMO it's not worth the risk. Charge to 14.2v then hold at 13.35v - you can now safely run your engine for 10minutes or 10days without any risk of overcharge. Quote Link to post Share on other sites
CarpeDiem 430 Posted April 14 Author Share Posted April 14 25 minutes ago, B00B00 said: Yup my battery monitor is a Victron BMV 702 as well as my 3 Solar regulators. All Bluetooth on my phone. see attached screenshot of all victron units. Note that screenshot was taken in at night and the top one is on the start battery hense the different voltage readings. Yes there is alternator and battery temperature sensors on the regulator. Also a picture of the alternator type and boat for reference. You could do well to install a Victron SmartShunt. These can network with the Smart MPPT units turning them into a syncronised charger. The synchronisation occurs over Bluetooth. A boat I helped on recently had three chargers like you and they were all all over the place. By networking them to the SmartShunt they are now able to fully charge the LFP every time. We've set a charge voltage of 14.2v with a tail termination of 0.03C and it works a treat. Just need to confirm that the model mppt you have is compatible with the Bluetooth networking option... Quote Link to post Share on other sites
Adrianp 120 Posted April 15 Share Posted April 15 Keeping the alternator cool makes a huge difference for these small frame Balmar alternators. We have 2x 175a Balmar XTs and they very quickly overheat (our 614 is programed to not let them get hotter than 90c) and they very quickly reach that point, then cut their output to about half. To keep them running with a decent output, I have to have an bilge blower sucking the hot air right off the alternator. If that fan stops, the alternator will throttle itself back within a minute or two. 3 Quote Link to post Share on other sites
Island Time 1,239 Posted April 15 Share Posted April 15 Just a note here. That install does not meet ABYC or AS/NZS standards for a Lithium install. That COULD cause an insurance problem. Most of the issue it it has no external comms to "provide visual and audible" warning of an impending shutdown - but it's unlikely to ever shut down as there are, in effect, 4 BMS's making 4 banks... Quote Link to post Share on other sites
CarpeDiem 430 Posted April 15 Author Share Posted April 15 2 hours ago, Island Time said: Just a note here. That install does not meet ABYC or AS/NZS standards for a Lithium install. That COULD cause an insurance problem. Most of the issue it it has no external comms to "provide visual and audible" warning of an impending shutdown As the standard is not legislated in leisure craft it would only cause an issue with your insurance if and only if your insurance company required compliance with the specific (or latest) standard. My insurance policy has no such wording. 2 hours ago, Island Time said: but it's unlikely to ever shut down as there are, in effect, 4 BMS's making 4 banks... As the banks are in parallel then if the voltage goes high, eg, 14.7v all 4 BMS's will shutdown within seconds of each other. Likewise a continuous current draw of merely a few amps that brings a single cell to the low voltage disconnect level will have a cascading effect across all 4 BMS's and they will all shut down within minutes of each other. Having multiple batteries in parallel does not reduce the likelihood of a BMS shutdown across all the batteries due to high or low cell voltage. Quote Link to post Share on other sites
Island Time 1,239 Posted April 15 Share Posted April 15 2 minutes ago, CarpeDiem said: As the standard is not legislated in leisure craft it would only cause an issue with your insurance if and only if your insurance company required compliance with the specific (or latest) standard. My insurance policy has no such wording. As the banks are in parallel then if the voltage goes high, eg, 14.7v all 4 BMS's will shutdown within seconds of each other. Likewise a continuous current draw of merely a few amps that brings a single cell to the low voltage disconnect level will have a cascading effect across all 4 BMS's and they will all shut down within minutes of each other. Having multiple batteries in parallel does not reduce the likelihood of a BMS shutdown across all the batteries due to high or low cell voltage. The standards makes no allowance for "leisure craft". ABYC E13 OR AUS/NZS 3004. Just because a craft is not inspected doesn't exempt it . Yes I realize a standard itself is not law. Yes, there are situations that could take out all the BMS units together. High (or low voltage) is an example. Much more likely is a single cell tripping one BMS - high or low temp, high or low voltage due to balance or other issues. IMO. Quote Link to post Share on other sites
CarpeDiem 430 Posted April 15 Author Share Posted April 15 Just now, Island Time said: The standards makes no allowance for "leisure craft". ABYC E13 OR AUS/NZS 3004. Just because a craft is not inspected doesn't exempt it . Yes I realize a standard itself is not law. Yep. My point is that the standard isn't a requirement for leisure craft. Because is not cited by the regulations that apply to leisure craft. However, it is legal requirement for commercial vessels that operate under Maritime NZ Rule 60. Quote Link to post Share on other sites
CarpeDiem 430 Posted April 15 Author Share Posted April 15 7 minutes ago, Island Time said: Yes, there are situations that could take out all the BMS units together. High (or low voltage) is an example. Much more likely is a single cell tripping one BMS - high or low temp, high or low voltage due to balance or other issues. Agree 100%. Quote Link to post Share on other sites
ballystick 73 Posted April 15 Share Posted April 15 12 hours ago, Island Time said: The standards makes no allowance for "leisure craft". ABYC E13 OR AUS/NZS 3004. Just because a craft is not inspected doesn't exempt it . Yes I realize a standard itself is not law. Yes, there are situations that could take out all the BMS units together. High (or low voltage) is an example. Much more likely is a single cell tripping one BMS - high or low temp, high or low voltage due to balance or other issues. IMO. I have checked the fine print in my insurance policy and I can't find any reference to the above standard or anything regarding Lithium batteries, there must be heaps of Lithium batteries installed already especially with the promotion of Drop-In units, we'll see what the future brings Quote Link to post Share on other sites
harrytom 648 Posted April 17 Share Posted April 17 On 16/04/2024 at 8:16 AM, ballystick said: I have checked the fine print in my insurance policy and I can't find any reference to the above standard or anything regarding Lithium batteries, there must be heaps of Lithium batteries installed already especially with the promotion of Drop-In units, we'll see what the future brings Until you make a claim, the insurance companies are a law under themselves. Its there job not to pay out! Quote Link to post Share on other sites
Black Panther 1,591 Posted April 17 Share Posted April 17 Insurance is a piece of paper to get you into marinas. Quote Link to post Share on other sites
ballystick 73 Posted April 17 Share Posted April 17 Why is it so critical to have an audible alarm for low voltage? This seems to be a regulation for commercial operations or similar. Quote Link to post Share on other sites
K4309 268 Posted April 17 Share Posted April 17 All the above is why I went for lead-carbon over lithium. Much the same reason as why Aardvark when for a kerosene stove over LPG. It avoids a whole lot of compliance issues. Standard charging profile and voltage profile, no need for a BMS and no risk of blowing the alternator in an uncontrolled load dump. Quote Link to post Share on other sites
Island Time 1,239 Posted April 18 Share Posted April 18 5 hours ago, ballystick said: Why is it so critical to have an audible alarm for low voltage? This seems to be a regulation for commercial operations or similar. Because the battery will turn off, possibly at a critical moment - no lights, no nav gear etc. Known as "dark ship". That's what the regs are trying to avoid. 2 Quote Link to post Share on other sites
Island Time 1,239 Posted April 18 Share Posted April 18 4 hours ago, K4309 said: All the above is why I went for lead-carbon over lithium. Much the same reason as why Aardvark when for a kerosene stove over LPG. It avoids a whole lot of compliance issues. Standard charging profile and voltage profile, no need for a BMS and no risk of blowing the alternator in an uncontrolled load dump. I have taken multiple sets (3) of lead carbon batts out of customers boats this year - premature failures, all approx 2 years old.. All have gone Lifepo4 1 Quote Link to post Share on other sites
K4309 268 Posted April 18 Share Posted April 18 2 hours ago, Island Time said: I have taken multiple sets (3) of lead carbon batts out of customers boats this year - premature failures, all approx 2 years old.. All have gone Lifepo4 What brand? Quote Link to post Share on other sites
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