Lithium Batteries installation

[magnetman]

1 hour ago, MtB said:

 

FTFY!

 

 

What is the object of a battery isolator switch? 

 

is it just for fun or a piece of safety equipment? 

 

What happens if there is a large unexpectedly large loaf on the battery and the switch gets welded closed by high currents? 

 

This could be a bit nasty and call for disconnection. 

 

 

[nicknorman]

1 minute ago, magnetman said:

 

What happens if there is a large unexpectedly large loaf on the battery and the switch gets welded closed by high currents? 

 

Well at least you will be able to have a nice luncheon. Or several in fact.

[rusty69]

31 minutes ago, magnetman said:

What happens if there is a large unexpectedly large loaf on the battery and the switch gets welded closed by high currents? 

I expect it will rise to the occasion 

Currant bread is rather nice 

[Alan de Enfield]

49 minutes ago, magnetman said:

What happens if there is a large unexpectedly large loaf on the battery and the switch gets welded closed by high currents?

 

It's toast !

[magnetman]

The red key on the top might make People think it does something. 

Just now, Alan de Enfield said:

 

It's toast !

Crumbs ! What have I done. 

 

 

[MtB]

1 hour ago, magnetman said:

What is the object of a battery isolator switch? 

 

is it just for fun or a piece of safety equipment? 

 

 

Neither.

 

Its purpose is to get you a BSS pass, obviously.

 

 

So you can get  licence.

 

 

 

[IanD]

3 hours ago, nicknorman said:

Generally the advice from here for disconnecting a battery, is to disconnect the negative first. This is because if you touch the hull with the spanner, it doesn't matter. If you disconnect the positive first and touch the hull, you have a molten spanner. Once the negative is disconnected you can remove the postive connection and if the spanner touches the hull, nothing happens.

 

 

 

You really should write a book. After all, you have designed almost everything from the entire Apollo moon landing software (which lets face it was pretty simple!) to the latest AI systems that can recognise a face from orbit. And everything in between. It would be fascinating, although rather long.

Although I do curse you when I find that on my iPhone the ringer volume and the alarm volume are inseparable. What were you thinking of when you designed that bit?

This is exactly what I said earlier.  To paraphrase "just as well I decided not to have any ground connections through any data cables as there would be a risk of harm to them or the PCB tracks (or the BMS accuracy) if I had done."

Having a ground connection would be the default, not having a ground connection was the result of considering the alternative current paths issue. This is the incredibly basic point of logic that you don't seem to get. Perhaps you are a badly trained AI after all?

By your logic, I avoided a problem with alternative ground paths by not having an alternative ground connection, therefore the potential issue of alternative ground connections doesn't exist. Ever. At all.

Does not compute. Back to the training data for you! Oh and forget the ad hominem attack thing, that only applies to humans.

<sigh> exactly the response I predicted... 😞

 

Apart from personal abuse and insults, do you have anything useful to contribute to the subject of the thread?

Edited February 13 by IanD

[nicknorman]

10 hours ago, IanD said:

<sigh> exactly the response I predicted... 😞

 

Apart from personal abuse and insults, do you have anything useful to contribute to the subject of the thread?

I suppose I could continue to repeat myself, but what would be the point? Your interpreter algorithm is malfunctioning. Maybe you should stick this into your OS, being binary your parser might understand it more easily:

 

01000001 01110110 01101111 01101001 01100100 01101001 01101110 01100111 00100000 01100001 01101100 01110100 01100101 01110010 01101110 01100001 01110100 01101001 01110110 01100101 00100000 01100111 01110010 01101111 01110101 01101110 01100100 00100000 01110000 01100001 01110100 01101000 01110011 00100000 01101001 01110011 00100000 01100001 00100000 01100111 01101111 01101111 01100100 00100000 01110100 01101000 01101001 01101110 01100111 00101110

Edited February 14 by nicknorman

[rusty69]

The quick brown 🦊 jumps over 13 lazy 🐶.

[magnetman]

LTO batteries are interesting

I am also intrigued about the suggestion of using resistors and heatsinks to alter the voltage and current out of the alternator. It seems that if done nice and tidy this could be a better solution than the iece of wire .

Putting the resistor in a water heating system seems interesting even if it is not going to be much power .

[nicknorman]

34 minutes ago, magnetman said:

LTO batteries are interesting

I am also intrigued about the suggestion of using resistors and heatsinks to alter the voltage and current out of the alternator. It seems that if done nice and tidy this could be a better solution than the iece of wire .

Putting the resistor in a water heating system seems interesting even if it is not going to be much power .

 

Yes just add a resistor into the field circuit. Around 4.25A maximum current at 14v seems fairly typical for a boat alternator field current, ie a field resistance of 3.3ohms. To limit the current to 2.5A (alternator limited to 60% of maximum output) you would need to increase the resistance to 5.6 ohm, ie add 2.2 ohm resistor. 2.2 ohms at 2.5A will dissipate ~14 watts. You could use a 25w resistor but I would choose a 50w wirewound chassis mount one, and it would need to be on a heatsink/metal plate because it would get extremely hot even at 14watts if not so mounted. I've been saying this for years, but I don't think anyone has ever tried it.

[Tony Brooks]

16 hours ago, GUMPY said:

There were no double pole high current switches available then.

 

I take the general point but I think incorrect. For as long as I can remember, CAV produced double pole master switches for buses, coaches and vehicles that had to be wired insulated return because of dangerous cargoes. I accept they were not readily available at the local chandler and most boaters would not pay for them.

[magnetman]

15 minutes ago, nicknorman said:

 

Yes just add a resistor into the field circuit. Around 4.25A maximum current at 14v seems fairly typical for a boat alternator field current, ie a field resistance of 3.3ohms. To limit the current to 2.5A (alternator limited to 60% of maximum output) you would need to increase the resistance to 5.6 ohm, ie add 2.2 ohm resistor. 2.2 ohms at 2.5A will dissipate ~14 watts. You could use a 25w resistor but I would choose a 50w wirewound chassis mount one, and it would need to be on a heatsink/metal plate because it would get extremely hot even at 14watts if not so mounted. I've been saying this for years, but I don't think anyone has ever tried it.

Water cooled could be interesting. 

[dmr]

11 minutes ago, nicknorman said:

 

Yes just add a resistor into the field circuit. Around 4.25A maximum current at 14v seems fairly typical for a boat alternator field current, ie a field resistance of 3.3ohms. To limit the current to 2.5A (alternator limited to 60% of maximum output) you would need to increase the resistance to 5.6 ohm, ie add 2.2 ohm resistor. 2.2 ohms at 2.5A will dissipate ~14 watts. You could use a 25w resistor but I would choose a 50w wirewound chassis mount one, and it would need to be on a heatsink/metal plate because it would get extremely hot even at 14watts if not so mounted. I've been saying this for years, but I don't think anyone has ever tried it.

 

A good idea but that "just" is a bit of an over-simplification. You will have to mess about with the innards of the alternator to break the field circuit and bring wires from both sides of the break out of the alternator, so a fair bit more difficult than the usual Adverc type mod (difficulty depends on design of alternator/regulator).

 

Maybe its time for you to update and open-source your regulator design to compete with the Zeus? 😀

 

Just now, magnetman said:

Water cooled could be interesting. 

 

Many years ago a mate of mine moved the power transistors from his hifi out of the enclosure on longish wires and had each one sat in a saucer of water.

[magnetman]

 

It seems an interesting approach to me. 

 

[nicknorman]

23 minutes ago, dmr said:

 

A good idea but that "just" is a bit of an over-simplification. You will have to mess about with the innards of the alternator to break the field circuit and bring wires from both sides of the break out of the alternator, so a fair bit more difficult than the usual Adverc type mod (difficulty depends on design of alternator/regulator).

 

Maybe its time for you to update and open-source your regulator design to compete with the Zeus? 😀

 

 

Many years ago a mate of mine moved the power transistors from his hifi out of the enclosure on longish wires and had each one sat in a saucer of water.

 

The "just" also applies to the expensive Wakespeed, Zeus, Alpha Pro etc in that you need to disconnect the existing regulator and access the brushes directly. Much the same amount of work, and although I would agree it is not an entirely trivial thing, someone with reasonable mechanical and electrical competence should be able to do it. I did! The advantage over the above alternator controllers is that it is a massively cheaper solution! You could of course also add a switch into the field circuit to "disable" the alternator gracefully once the Li was charged.

 

I am always happy to share my alternator controller design but one problem is that it was designed to be integral to a system, not stand alone. It currenly looks at individual cell voltages and battery temperature (which it gets from the custom BMS), and battery current and SoC (from BMV712) to control charging, as well as being aware if the BMS is about to emergency disconnect the battery. The software could be re-written to be blind to all that but then there is the risk that a drop-in BMS would decide to disconnect the battery with the alternator controller being unaware until it detects a rapid rise in system voltage.

 

[peterboat]

1 hour ago, Tony Brooks said:

 

I take the general point but I think incorrect. For as long as I can remember, CAV produced double pole master switches for buses, coaches and vehicles that had to be wired insulated return because of dangerous cargoes. I accept they were not readily available at the local chandler and most boaters would not pay for them.

You are right Tony  I do a day a week in a bus museum or transport museum depending on who you speak to. Anyway they are doable pole as I asked Dave the manager of service and repair 

[dmr]

36 minutes ago, nicknorman said:

 

The "just" also applies to the expensive Wakespeed, Zeus, Alpha Pro etc in that you need to disconnect the existing regulator and access the brushes directly. Much the same amount of work, and although I would agree it is not an entirely trivial thing, someone with reasonable mechanical and electrical competence should be able to do it. I did! The advantage over the above alternator controllers is that it is a massively cheaper solution! You could of course also add a switch into the field circuit to "disable" the alternator gracefully once the Li was charged.

 

I am always happy to share my alternator controller design but one problem is that it was designed to be integral to a system, not stand alone. It currenly looks at individual cell voltages and battery temperature (which it gets from the custom BMS), and battery current and SoC (from BMV712) to control charging, as well as being aware if the BMS is about to emergency disconnect the battery. The software could be re-written to be blind to all that but then there is the risk that a drop-in BMS would decide to disconnect the battery with the alternator controller being unaware until it detects a rapid rise in system voltage.

 

 

I disabled the regulator in my 100amp Iskra recently and it was a right pain, quite thick pins and not enough clearance to get in with any of my snips so a slow and fiddly dremmel job.

 

My comment on open sourcing your design was a bit light hearted. There are several electronic engineers on this forum so we could have done a good job, but the Arco Zeus is close enough to what is needed so much less justification for a DIY alternative (and if we value our time even at half minimum wage it would still cost more than £850).

 

Something like an alternative to the Victron Gerbo/GX might be a good open source project as it would be good to have a bit more flexibility than Victron provide.

 

Current plan is to get the Zeus, maybe later this week, get it going with the Trojans then get a Lithium. The battery box does not fit any off the shelf lithiums too well so its either a lot of wasted space or making my own from cells.

 

Making up for the lost weight of the Trojans will be an issue. 😀

 

Phase two will be to replace the Travel Power with a big inverter and second alternator with its own battery bank but can't decide between 24 or 48 volts. I suspect things might change quite a bit in the next year or two so will delay on this unless the TravelPower fails.

[magnetman]

Some of the rack mounted 48v LFP batteries look nice. 

 

 

[nicknorman]

14 minutes ago, dmr said:

 

I disabled the regulator in my 100amp Iskra recently and it was a right pain, quite thick pins and not enough clearance to get in with any of my snips so a slow and fiddly dremmel job.

 

My comment on open sourcing your design was a bit light hearted. There are several electronic engineers on this forum so we could have done a good job, but the Arco Zeus is close enough to what is needed so much less justification for a DIY alternative (and if we value our time even at half minimum wage it would still cost more than £850).

 

Something like an alternative to the Victron Gerbo/GX might be a good open source project as it would be good to have a bit more flexibility than Victron provide.

 

Current plan is to get the Zeus, maybe later this week, get it going with the Trojans then get a Lithium. The battery box does not fit any off the shelf lithiums too well so its either a lot of wasted space or making my own from cells.

 

Making up for the lost weight of the Trojans will be an issue. 😀

 

Phase two will be to replace the Travel Power with a big inverter and second alternator with its own battery bank but can't decide between 24 or 48 volts. I suspect things might change quite a bit in the next year or two so will delay on this unless the TravelPower fails.

 

I will be really interesting to hear how you get on with the Zeus. It certainly looks a good product, although possibly a somewhat immature one. One of those products that has been taken to the market before all the intended features are actually functional. Seems to be the way of things these days!

 

Definitely an issue with the weight lost, we had to get a couple of 28lb weights to replace the Trojans, even though we went up from 450Ah to 600Ah

 

You could of course just get cells like I did, and add a cots BMS. At least that allows you to locate the cells in the existing space (and in our case, the 600 Ah Li had a smaller footprint than the 450 Ah Trojans, although they were taller). I used https://blslifepo4battery.com/  without any issues, pleased with the product and price although that was a couple of years ago. And has the advantage that you have direct access to the BMS and its configuration.

[dmr]

18 minutes ago, magnetman said:

Some of the rack mounted 48v LFP batteries look nice. 

 

 

Yes, but there is very limited choice of 48 volt alternators, and a DC-DC converter/charger between the 12v and 48v banks would be good and these are also a bit limited at present. I suspect more 48 volt stuff will become available quite soon. The proposed Victron bi-directional unit mention somewhere in this thread might be good.

The rack mounted batteries do look good but boat batteries are often tucked away out of sight so any displays would be invisible and so standard boxed up batteries are probably a better choice. Also the racks are intended for domestic use so its just possible that they wont handle the bangs quite as well.

9 minutes ago, nicknorman said:

 

I will be really interesting to hear how you get on with the Zeus. It certainly looks a good product, although possibly a somewhat immature one. One of those products that has been taken to the market before all the intended features are actually functional. Seems to be the way of things these days!

 

Definitely an issue with the weight lost, we had to get a couple of 28lb weights to replace the Trojans, even though we went up from 450Ah to 600Ah

 

You could of course just get cells like I did, and add a cots BMS. At least that allows you to locate the cells in the existing space (and in our case, the 600 Ah Li had a smaller footprint than the 450 Ah Trojans, although they were taller). I used https://blslifepo4battery.com/  without any issues, pleased with the product and price although that was a couple of years ago. And has the advantage that you have direct access to the BMS and its configuration.

Yes, I am concerned about the "bleeding edge" thing but as long as they have got the hardware right then firmware updates should fix things. I have had a play with the phone app in demo mode and it does look like functionality is missing.

 

I don't have a lot of choice really, have just had to replace the alternator (and improved the cabling) and it now runs a little hotter going from just about ok to just about not ok, so I need something with temperature control.

 

Ive got 6 Trojans but can only get 560Ah of lithium in the box unless I do my own from cells. Thats 168kg down to 60kg and right at the far edge of the boat.

[IanD]

1 hour ago, dmr said:

 

I disabled the regulator in my 100amp Iskra recently and it was a right pain, quite thick pins and not enough clearance to get in with any of my snips so a slow and fiddly dremmel job.

 

My comment on open sourcing your design was a bit light hearted. There are several electronic engineers on this forum so we could have done a good job, but the Arco Zeus is close enough to what is needed so much less justification for a DIY alternative (and if we value our time even at half minimum wage it would still cost more than £850).

 

Something like an alternative to the Victron Gerbo/GX might be a good open source project as it would be good to have a bit more flexibility than Victron provide.

 

Current plan is to get the Zeus, maybe later this week, get it going with the Trojans then get a Lithium. The battery box does not fit any off the shelf lithiums too well so its either a lot of wasted space or making my own from cells.

 

Making up for the lost weight of the Trojans will be an issue. 😀

 

Phase two will be to replace the Travel Power with a big inverter and second alternator with its own battery bank but can't decide between 24 or 48 volts. I suspect things might change quite a bit in the next year or two so will delay on this unless the TravelPower fails.

 

I'm not sure how much more flexibility you'd get -- the Cerbo as it stands can do quite a lot with the standard Victron software, a lot of third party hardware (e.g. batteries/BMS/alternators/generators) is supported, there are a lot of assistants to do various boaty things and they're all documented, supported and debugged. If you want to do more complex sensing/control/sequencing then Node Red is a standard additional install, again documented and with a lot of community support. There's a big advantage to having things that many other people have tried and debugged, even if your system is different to theirs... 😉

 

The other point is that the firmware/software is regularly updated, either to fix bugs or to add new features, and that this is all documented/supported too. Two examples I can think of are the recent additions of solar/wind priority and much enhanced generator control, and there's a big new GUI upgrade coming soon which will make the UI much easier to use and adds in a lot of the features that users have added over the years through packages like GuiMods.

 

Then there's remote monitoring/control/alarms and data logging via VRM on both PCs and smartphones/tablets -- this is especially useful if the rest of your gear is also Victron, but many people use Cerbos with third party gear as well and use VRM to monitor/control this too. I've had notifications from VRM for shoreline disconnection (marina error) and also when my mobile provider cocked up SIM renewal and the router went down, via an alarm timeout if comms disappears for more than a few hours (which could be bad weather).

 

It's not absolutely perfect but it all works pretty well and can do an awful lot. Of course it would be possible to recreate all this yourself -- just like you could write your own PC OS -- and some people have, but it would be a lot of effort, and you wouldn't get the benefit of free updates and debugging by other people who spot problems/bugs before you do... 😉

 

(you can of course run Venus OS on something like a Raspberry Pi as well as a Cerbo and many other platforms, then you'd get a lot of the software support but much less hardware support).

 

The 24V vs. 48V question very much depends what you want to power from it (and charge it) and what you have already. 48V is cheaper for big inverters/combos (lower current) but almost nothing DC runs off this other than the inverter, unless (like me) you have a 48V motor and bow thruster. A lot of onboard electrical gear (lights, pumps...) is easily available in 24V if you're starting from scratch, but unless you're going to swap out all your 12V stuff you'll need a 24V-12V DC-DC converter anyway to supply this -- and in that case you could equally have a 48V-12V DC-DC. If you're planning to charge from an alternator then 24V ones are widely available and a lot cheaper than specialist 48V ones -- and you can put 2 24V ones in series if your engine allows this. But if you can only fit in one alternator with a polyvee drive 48V will give you more power, albeit at higher cost.

 

As so often, it all depends on your individual circumstances... 😉

 

Edited February 14 by IanD

[magnetman]

If there is a travelpower unit then it seems possible to run a 48v LFP charger from it. 

 

Maybe not very efficient. 

 

Other option is use less energy on the Boat. 

 

 

[IanD]

13 minutes ago, magnetman said:

If there is a travelpower unit then it seems possible to run a 48v LFP charger from it. 

 

Maybe not very efficient. 

 

Other option is use less energy on the Boat. 

 

 

The travelpower can be directly connected to an AC input of the charger or charger/inverter if you have one, depending on how many AC sources you have -- if only two (shoreline and Travelpower) this is trivial to do with something like a Victron Quattro, mine does the same with shoreline and generator and deals with switchover/control and prioritising and current limiting. Or you can add an external changeover switch if it only has one AC input, this is a bit more of a pain if you want switchover to happen automatically, especially if the different AC sources have different current limits.

 

Using less energy is an option, unless of course this doesn't suit your requirements... 😉

Edited February 14 by IanD

[dmr]

4 minutes ago, magnetman said:

If there is a travelpower unit then it seems possible to run a 48v LFP charger from it. 

 

Maybe not very efficient. 

 

Other option is use less energy on the Boat. 

 

 

The TravelPower is pretty much essential to our boaty lives, its the lovely old black box incarnation, but there is really now only Mr Cox who knows how to fix it and he admits that his spare parts will run out at some stage. I want a PlanB ready in case it dies (or Cox's loose interest) and this would be a dedicated 24/48 volt alternator/inverter/battery to completely replace the TravelPower.

I should really convert the whole boat to 24/48 and run the 12 volt system off a dc-dc dropper but I like the redundancy obtained from totally separate systems.

We did witness a boat fire a couple of years ago and this was down to running a washing machine off a 12 volt system. My own rule of thumb is 100amps max, 150 absolute max, so 24 or 48 is the way to go for washing machine.

 

We manage on 100Ah per day on the 12 volts so are not excessive users of leccy, but do like the washing machine.

I am also trying to do my bit for the environment and in our case more batteries works better than lots of solar.