ABYC and ISO Li reference diagram

[newhaul]

Originally Posted by goboatingnow

Sorry typo 240 Wp not Kwp

And yes I’m at 100 percent Soc as I have full tail current monitoring.

Sorry but I have a hard time believing that as I'm using 10ah less and with 200 watts running through a tracer MPPT I'm finally full by noon .

Now with any lead I would say you are close by 3pm with 240 and 35ah usage,
If your up by the time you say then your not using what you think you are.
Laws of physics and all

[newhaul]

Originally Posted by goboatingnow

I have a small system 240 AH VRSLA


.

Wait your running valve regulated sealed lead acid batteries ?

Why do you need all the BMS that we running LIFEPO4 are discussing ?
Just wondering . I have been running lfp house for 3 years full time liveaboard.

[goboatingnow]

Originally Posted by newhaul

Wait your running valve regulated sealed lead acid batteries ?



Why do you need all the BMS that we running LIFEPO4 are discussing ?

Just wondering . I have been running lfp house for 3 years full time liveaboard.

I have a LFP upgrade project underway. I use LFP in several commercial projects I was involved in. My upgrade is waiting for me to finish my alternator controller and my own BMS.

I’ve been involved in battery tech for decades as I developed in areas that relied on battery power.

[goboatingnow]

Originally Posted by newhaul

Sorry but I have a hard time believing that as I'm using 10ah less and with 200 watts running through a tracer MPPT I'm finally full by noon .



Now with any lead I would say you are close by 3pm with 240 and 35ah usage,

If your up by the time you say then your not using what you think you are.

Laws of physics and all

I consume 25 Ah over night hours , ie no solar

That’s loss is restored in summer by approx 11am , thus would be about 6 hours of solar which is well able to replace that. The battery system has extensive monitoring so I’m entirely happy I’m getting 100 SOC

I’ve the LFP system in my lab for some time. Mainly running lots of tests and characteristics

My main issue is I’m negotiating with my insurers to get them to accept my qualifications and regard the system as professionally designed and installed. ( which it Is ) I’m now hopeful no deductible will be applied. ( Things are delayed due to lightening strike electronics replacement. ) but it looks like the insurers are coming around. ( ISO conformant install )

I used lithium including LFP a lot in projects and I’m a great fan of lithium.

We did some really high speed lithium chargers that were crazy quick.

By the way. As I said at the start this thread was to post and demonstrate RGleasons proposed install not mine. This was never about mine ( I have very different approaches )

LFP in my case will add little. But as I have the batteries ( from an industrial project ) and it’s my electronics so it integrates into the boats monitoring system , I might add well do the install soonish.

[goboatingnow]

By the way I think one of the most useful and authoritative sources is “Battery Management Systems for Large Lithium-Ion Battery Packs” by Davide Andrea cover the topic in great detail

[rgleason]

Amazon Kindle $104

Battery Management Systems for Large Lithium Ion Battery Packs 1st Edition, Kindle Edition
https://www.elithion.com/

"Lithium-ion Batteries and Applications" - Li-ion book by Davide Andrea

[s/v Jedi]

Originally Posted by rgleason

Amazon Kindle $104

Battery Management Systems for Large Lithium Ion Battery Packs 1st Edition, Kindle Edition
https://www.elithion.com/

"Lithium-ion Batteries and Applications" - Li-ion book by Davide Andrea

Pricey book! I hope they include LiFePO4 in it.

I think there has been some misunderstanding about the ML-RBS. The manual override it has is for switching off only. You can not manually override the BMS by forcing it on… only off. So even that fully complies with ABYC.

[rgleason]

S/V Jedi. Thanks for clarifying this. Sorry to have mislead.

[hjohnson]

Originally Posted by s/v Jedi

Pricey book! I hope they include LiFePO4 in it.

I think there has been some misunderstanding about the ML-RBS. The manual override it has is for switching off only. You can not manually override the BMS by forcing it on… only off. So even that fully complies with ABYC.

Hmm? Maybe your ML-RBS is conveniently defective I know that I can manually turn my 7713 on by pressing down in the middle part of the knob and it will stay that way until I either manually turn it off, or it is operated electronically. Ie, after manually turning it on, if the BMS turns it on, then off again, it will power off. But it can be locked in the off position.

This is part of the reason I like it; if my BMS takes a dump, I can manually power my system back on and just have to watch the battery closely while I limp home to dock.

[s/v Jedi]

Originally Posted by hjohnson

Hmm? Maybe your ML-RBS is conveniently defective I know that I can manually turn my 7713 on by pressing down in the middle part of the knob and it will stay that way until I either manually turn it off, or it is operated electronically. Ie, after manually turning it on, if the BMS turns it on, then off again, it will power off. But it can be locked in the off position.

This is part of the reason I like it; if my BMS takes a dump, I can manually power my system back on and just have to watch the battery closely while I limp home to dock.

That is not how it works, but it appears that way to you. When the yellow lever is turned to the left, the BMS has full control. You can manually switch on and off, but the BMS can do as well plus it knows if you did so manually.

When you turn the yellow lever to the right, you override the BMS, it can no longer operate the solenoid, but the solenoid is locked in the off position and the only way to turn it on is by turning the lever left again, canceling the manual override of the BMS

[hjohnson]

Originally Posted by s/v Jedi

That is not how it works, but it appears that way to you. When the yellow lever is turned to the left, the BMS has full control. You can manually switch on and off, but the BMS can do as well plus it knows if you did so manually.

When you turn the yellow lever to the right, you override the BMS, it can no longer operate the solenoid, but the solenoid is locked in the off position and the only way to turn it on is by turning the lever left again, canceling the manual override of the BMS

Other than inference, there’s no way for the BMS to know that it’s been overridden. Yes, the BMS can take back control if it’s still alive, but it would have to cycle the solenoid to take control. If the BMS is failed, or powered off, you can manually force the circuit back on, which is what I would consider an override. But yes, it also has a lock-off position which you described (and another reason why I like it; I like my LO/TO mechanisms.

[s/v Jedi]

Originally Posted by hjohnson

Other than inference, there’s no way for the BMS to know that it’s been overridden. Yes, the BMS can take back control if it’s still alive, but it would have to cycle the solenoid to take control. If the BMS is failed, or powered off, you can manually force the circuit back on, which is what I would consider an override. But yes, it also has a lock-off position which you described (and another reason why I like it; I like my LO/TO mechanisms.

The BMS should read the state of the solenoid from the yellow wire. If this wire is 12V (or 24V for a 24V version) then the solenoid contact is OFF. If it is 0V/grounded, then the contact is ON.

So let’s assume the BMS opened the solenoid because of HVC. Then when you push in the knob to turn it on, the BMS should check voltage and if it’s still too high, turn it off again. Simple as that. An override is different, there you turn it on manually and the BMS can’t turn it off. This is how the diagram of this thread works, and why I don’t like it.

The RBS does it exactly right, but I know not all BMS’s do it right. Also, the mod from CatNewbee won’t work well: those need the 7713, auto releasing version to comply with ABYC, because the BMS expects to work with levels rather than with pulses. I know that REC sells an adapter but I am not sure if that works right either. If I had a REC BMS, I would use an ATTiny and programmy own adapter for the 7700 solenoid. It is 3 lines of code.

[PUDDLE JUMPER II]

Originally Posted by s/v Jedi

Okay, here is what I would change;

- at the house battery, attached straight to the positive terminal, this fuse block: https://www.bluesea.com/products/519...k_-_30_to_300A with this 250A fuse: https://www.bluesea.com/products/518...al_Fuse_-_250A

This eliminates a cable and brings the fuse as close to the battery as possible. All ABYC conform.

- from that fuse holder, a 2/0 cable, as short as possible, to this RBS: https://www.bluesea.com/products/770..._-_12V_DC_500A
followed by another 2/0 cable, straight to the Lynx distributor input terminal.
Note: this is the pulsed-control version, which can be found for less than $100 in places and ordered online for $160 every day or $120 during sale. To connect this to the REC BMS, you can use the very simple schematic developed by CatNewBee in his big LiFePO4 thread so that you don’t have to buy the adapter from REC.

Now you have “battery - fuse - cable - solenoid - cable - busbar” instead of “battery - cable - fuse - cable - switch - cable - solenoid - cable - manual switch - cable - cable - busbar”, eliminating 50% of components (only 6 instead of 12!)

Now for SLA:

- at SLA battery positive terminal, a short 1/0 cable to this fuse block: https://www.bluesea.com/products/519..._Common_Source

- from that fuse block same input terminal, another (2nd) short 1/0 cable to this switch: https://www.bluesea.com/products/600...th__Knob_-_Red and from that switch another 1/0 cable to the engine starter. Label switch as “engine start”
You can use a fuse for this circuit but traditionally it isn’t fused.

- on that same fuse block, a 250A fuse to a 1/0 cable to a second switch: https://www.bluesea.com/products/600...th__Knob_-_Red and from that switch another 1/0 cable to the Lynx distributor input terminal on the upper right side (like done for the negative cable) Label switch as “emergency parallel”

- on that same fuse block, a 30A fuse to a 6 AWG cable to an Orion Tr Smart 12-12 non-isolated. You do not have an isolated negative so no need for an isolated converter. This also eliminates one negative cable and you only need a thin diameter negative cable (input and output currents eliminate each other).

I guess this addresses the points?

Originally Posted by s/v Jedi

No, it is not exactly the same. First of all, the diagram has a fuse, a manual switch, a solenoid, and another manual switch, all in the primary circuit between battery positive and main bus bar.

Second, the solenoid with manual switch in the diagram are two separate components, interconnected with two extra cables. That is four items, where the RBS replaces all that with just one item.

Third, the solenoid in the diagram has a 130mA power consumption 24x7. The RBS has 0mA (that is zero mA). Thatis a big difference.

Fourth, the combination of solenoid with manual override switch, provides an incentive to manually bypassing the BMS to stop that 130mA consumption. The RBS has no consumption, so that incentive isn’t there.

As other have written: for such situations a momentary switch that can’t be defeated by sticking something in to hold it without touching is used for that. I have that in my motorhome.

Show us you solenoid powered on continuously for a week, temperature measured with an IR tempgun. A picture, just like I post all the time.

If you have 10Ah parasitic draw and don’t care to throw in another 3Ah then really, something is wrong. I know you’re gonna be happy with that but you obviously can not understand that others are not. I have a big solar array and big batteries, but I still care about this and find it unacceptable. Smaller boats care more about it.

There are plenty boats with 100Ah or 200Ah LiFePO4 batteries. I have a much bigger battery as well, but I don’t see the need to ridicule thise with smaller batteries! Many cruisers don’t want to have much electric at all.

Anyway, I tried my best to help and actually put an hour of my time into it. I wonder why I bothered.

I do appreciate your commentary and banter... As a newbie to Lithium, you would be surprised at what I am cutting and lasting out of these chats to create my own system shortly and more importantly -- I am able to understand everyone's different and unique perspective on risk, risk aversions and safety. Invaluable information I personally cherish--- for the safety if my family, those souls onboard I am accountable to God for, and my beloved fat bottom girl I sink so much time, and care keeping g her safely above Davie Jones locker...
A simple thank y'all for the discussion--- it not for naught...

[goboatingnow]

To suggest a person is going to engage a clearly labelled emergency override to save a 1-2 ah ( assuming net night time only consumption ) is simply a absolute nonsense argument. It’s deserves no place in a rational engineering arguments. Those battery switches can be padlocked anyway if really you think like this

I had a close look at the blue sea switch in my chandlery. Despite the crazy price. I can confirm the manual overuse effectively bypasses the relay.

Technically this is not fully ABYC compliance but but iso and ABYC use the condition “ under normal operation “so one could argue a bypass activation. Is not “ normal “

As I said thd ML as far as I can see uses electronics to effective a safety disconnect. To me this relay is not fail safe and PERSONALLY for me that’s a show stopper

Others may have alternative priorities , that’s fine but stop trying to connivence others your solution is “ best “ it ain’t , it’s just “different “

[goboatingnow]

To suggest a person is going to engage a clearly labelled emergency override to save a 1-2 ah ( assuming net night time only consumption ) is simply a absolute nonsense argument. It’s deserves no place in a rational engineering arguments. Those battery switches can be padlocked anyway if really you think like this

I had a close look at the blue sea switch in my chandlery. Despite the crazy price. I can confirm the manual overuse effectively bypasses the relay.

Technically this is not fully ABYC compliance but but iso and ABYC use the condition “ under normal operation “so one could argue a bypass activation. Is not “ normal “

As I said thd ML as far as I can see uses electronics to effective a safety disconnect. To me this relay is not fail safe and PERSONALLY for me that’s a show stopper

Others may have alternative priorities , that’s fine but stop trying to connivence others your solution is “ best “ it ain’t , it’s just “different “