Li-0n, these look interesting

[MtB]

9 minutes ago, magnetman said:

Tranzorbs sound pretty cool. 

 

 

 

 

I thought so too. Sounds like the sort of clothes shop you might find in Camden, like Cyberdog. 

 

 

[David Mack]

3 hours ago, David Mack said:

Are these simply drop-in replacements for lead acid batteries, or would other changes/equipment be needed?

So the general answer to my first question is 'no' then.

The context is that Belfast's electrics have all been removed for major hull work, and I am about to start putting it all back. Kit I already have and was proposing to (re)use includes single 175A alternator, dual sensing VSR 180W solar panel with Tracer 20A mppt controller. I have enough work (and cost) on with refitting so I am not really interested in bespoke solutions involving expensive controllers or home-built bits of interface kit. I will be getting an inverter and probably a mains charger, or maybe a combi (make and model(s) not determined) but my intention would be not to have the charger connected long term, relying on solar to keep the batteries topped up when the boat is not in use. Boat intended use is extended leisure cruising, with the boat left away from from home for up to a fortnight, or on the home mooring (which has power available) for longer periods.

Sounds like I should be going for conventional lead acid batteries.

[Alan de Enfield]

44 minutes ago, Tony1 said:

At 38kg its going to be a bugger to shift around, so you'd want to be careful with your back.

 

My batteries are 53kg-55kg each (and I have 6 of them), which have to be manhandled with me lying down, and lifting them over my stomach and lowering down into the battery box.

As the years go by I'm having to lift them higher and higher !!

[nicknorman]

29 minutes ago, dmr said:

I think Wakespeed only does CANbus rather than Victron, but they are pretty similar????

A good project would be to make a "system integrator" box based on a micro controller, a bit like an open source version of the Victron system. This could talk to the batteries and the various charge devices using VE bus and CANbus etc, and have a good display. But there is still the issue that most battery BMS systems only do Bluetooth.

Trouble is I just don't have any time. Took last year off to build a mooring so neglected the boat a bit. Next year need to come out of the water to do the baseplate, an engine rebuild (or replacement), quite a lot of painting, and investigate a big land based solar setup at the mooring. And I am still doing a bit of software writing to earn a bit of money. And I want to go and look at the Lee and Stort and Wey 😀  

Wakespeed advertise compatibility with the Cerbo GX which is one of Victron’s “data concentrator” (aka system integrator) devices along with the Venus etc. so I would hazard a guess that with a BMV712 connected to the Cerbo connected to the Wakespeed, you could set it up to stop charging at a specified SoC. You would need some means to fully charge to 100% from time to time, to resynchronise the BMV.

[Tony1]

6 minutes ago, Alan de Enfield said:

 

My batteries are 53kg-55kg each (and I have 6 of them), which have to be manhandled with me lying down, and lifting them over my stomach and lowering down into the battery box.

As the years go by I'm having to lift them higher and higher !!

 

In all honesty Alan, I would get some help with that job. 55kg is a big weight to be hauling around. 

You're obviously familiar with this job, but in many cases the problem is that when getting very heavy batteries into place, you sometimes have to twist, or lift them in an unexpected way, or extend your arms a bit further than expected- and the temptation is to go for it, put that extra effort in, and just get the job done. 

I would probably risk it with one big battery to move, but I would be worried that it only takes a fraction of undue strain or force to cause a back injury. 

Having seen the results of a back injury at close quarters, and the suffering that this poor guy went through, it has made me pause many times, and give thought to back safety. 

 

[n-baj]

3 hours ago, GUMPY said:

What does the team think?

 

https://www.fogstar.co.uk/products/lithium-leisure-battery-fogstar-drift-105ah

105_SpecSheet_V.2_1.pdf 309.38 kB · 7 downloads

I have the 460ah version simply because it’s the cheapest per ah and is roughly the same size as 3 120ah lead acid. 
 

I’ve only done a dozen cycles on the battery so it’s very early days but I no longer have to nanny the battery bank making sure they’re fully charged, obsessing about mooring for the best solar, etc. I'm personally happy so far that there’s no faults from what I can see and it hasn’t spontaneously combusted.

 

There’s also an app which connects to the battery bms via Bluetooth (see attached pics)

[Tony1]

35 minutes ago, David Mack said:

. Boat intended use is extended leisure cruising, with the boat left away from from home for up to a fortnight, or on the home mooring (which has power available) for longer periods.

Sounds like I should be going for conventional lead acid batteries.

 

If you're going to spend most days doing long cruises then yes, a set of lead acids would perform well enough. All you need is enough charge to run your fridge overnight, plus some TV/laptop running, etc. Then next morning you're off and cruising (and charging) again.

If you were going to be spending 4 or 5 days per week not moving, then lithiums and a strong charging system would have some advantages. 

I did find that my lead acids didnt run the kettle or microwave very well at all, but to be fair the batteries were a bit shot at the time, so it wasnt a fair test of them. 

 

[beerbeerbeerbeerbeer]

1 hour ago, dmr said:

Victron actually have a float setting and a maintenance setting that is a fair bit lower than float

after a float of 13.5v (I think) my Victron charger then goes into ‘storage’ mode and charges at 13.2v for lead batteries. 



 

 

[dmr]

13 minutes ago, Goliath said:

after a float of 13.5v (I think) my Victron charger then goes into ‘storage’ mode and charges at 13.2v for lead batteries. 



 

 

Yes, Storage mode, that is the word I was looking for. I think sometimes maintenance is used to mean equalisation but not sure about that?

[PeterF]

5 hours ago, dmr said:

I need to learn more about this (Maybe Nick Norman will comment).

If lithium is a drop in replacement with solar/mains charging then I am thinking that a full drop in replacement is possible, just need to take the regulator out of the alternator and fit something like the Wakespeed controller.

Is it possible to have a safe lithium system using a system that measures charge voltage and goes into float? or is communication with the battery BMS essential?

 

The Wakespeed is biggish money but not that big as part of a full Lithium system.

The Wakespeed system is good in that is measures current as well as voltage so cuts absorption stage off based on tail current and goes to float. However, if the BMS in a drop in battery shuts off charge acceptance whilst the alternator is at high current delivery then you could still get damage due to the lack of communication.

 

When linked to such as a Victron BMS, REC BMS or 123BMS via CAN BUS, the BMS tells the Wakespeed what charge current to supply, so on shutdown they get told to stop charging. Additionally, many of these also have disable charge relays which you connect to a "feature in" wire on the Wakespeed which can be configured to also stop charging. If you have a full Victron system with their Multiplus inverter/charger and MPPT solar controller all connected to a Cerbo GX then any of the 3 BMSs listed above the Cerbo Gx can be configured to manage the charging of the all charging sources.

 

I have a Wakespeed ready for install. If I was going to use drop in lithiums with the Wakespeed I would still use a system with a lead acid buffer battery to absorb any voltage spikes on BMS detect.

 

If you have a BMV700 battery monitor then you can connect the SOC controlled relay on this to the "feature in" wire on the Wakespeed so that you terminate charging by going to float. You can also do this from the Cerbo GX relay but need to do a workaround as the relays are not directly controllable by SOC. You have to set the relay up as a generator auto start/stop so perhaps set it up to start charging below 60% and end charging at 80%. As NickNorman said above, you need to go to 100% every so often to eliminate drift in the BMV700.

Edited September 21, 2023 by PeterF

[nicknorman]

26 minutes ago, PeterF said:

The Wakespeed system is good in that is measures current as well as voltage so cuts absorption stage off based on tail current and goes to float. However, if the BMS in a drop in battery shuts off charge acceptance whilst the alternator is at high current delivery then you could still get damage due to the lack of communication.

 

When linked to such as a Victron BMS, REC BMS or 123BMS via CAN BUS, the BMS tells the Wakespeed what charge current to supply, so on shutdown they get told to stop charging. Additionally, many of these also have disable charge relays which you connect to a "feature in" wire on the Wakespeed which can be configured to also stop charging. If you have a full Victron system with their Multiplus inverter/charger and MPPT solar controller all connected to a Cerbo GX then any of the 3 BMSs listed above the Cerbo Gx can be configured to manage the charging of the all charging sources.

 

I have a Wakespeed ready for install. If I was going to use drop in lithiums with the Wakespeed I would still use a system with a lead acid buffer battery to absorb any voltage spikes on BMS detect.

 

If you have a BMV700 battery monitor then you can connect the SOC controlled relay on this to the "feature in" wire on the Wakespeed so that you terminate charging by going to float. You can also do this from the Cerbo GX relay but need to do a workaround as the relays are not directly controllable by SOC. You have to set the relay up as a generator auto start/stop so perhaps set it up to start charging below 60% and end charging at 80%. As NickNorman said above, you need to go to 100% every so often to eliminate drift in the BMV700.

There is talk in the Wakespeed manuals about the use of avalanche diodes (similar idea to zener diodes) on modern alternators. Our Iskra 12v 175A has such diodes. This should result in no more than about 36v transient from a full output load dump. Still, 36v is quite a lot hence why I fitted the tranzorb bank. Or Sterling do a similar thing for more £££s. I would caution against the hybrid system (lead acid in parallel) since it seems that for some reason, BSS are dead against it and at some point in the future this might become problematic.

[magnetman]

I'd be putting in a small lithium battery like the one in the OP for the solar and an AGM battery for the engine alternator. 

 

One of the main consumers on boats is often a fridge so it makes sense to run this from the solar during the bright season and add a small inverter to take advantage of any extra power available through the solar panels.

 

You can link the two together with wires if needed for certain situations. 

 

 

Bit of a fan of separate systems and redundancy. 

 

Also in this scenario if the BS scheme gets uppity you have a simple lead based system in place already. 

 

Quality AGM such as Victron supercycle are actually very good batteries.

[David Mack]

2 minutes ago, nicknorman said:

I would caution against the hybrid system (lead acid in parallel) since it seems that for some reason, BSS are dead against it and at some point in the future this might become problematic.

And would that preclude systems in which a domestic lithium bank is paralleled with a lead acid engine battery when charging by means of a charge relay or VSR? So you would need twin alternators and completely separate domestic and engine systems (or a lithium start battery).

[nicknorman]

5 minutes ago, David Mack said:

And would that preclude systems in which a domestic lithium bank is paralleled with a lead acid engine battery when charging by means of a charge relay or VSR? So you would need twin alternators and completely separate domestic and engine systems (or a lithium start battery).

Who knows what the BSS might end up with! They don’t seem particularly well up on the issues. But I would have thought your proposal was a reasonable compromise. The batteries would not be directly in parallel.

The issue originates from various Li manufacturers who say “do not mix with batteries of a different chemistry” as an arse covering comment in the installation manuals.

[GUMPY]

I think that all this paranoia about not going over 80% is just that paranoia mainly due to not having a decent charge controller/BMS.

My SolaX system at home,  yes the batteries are 234vDC, regularly charges to 100% then it shuts down.

At 90% it starts to reduce the current from the panels then at 96% it's down to almost zero and the BMS shuts the battery down at 100%

I'm away at present so using very little battery power maybe 15% between sunset and sunrise.

 

 

Edited September 21, 2023 by GUMPY

[dmr]

27 minutes ago, nicknorman said:

There is talk in the Wakespeed manuals about the use of avalanche diodes (similar idea to zener diodes) on modern alternators. Our Iskra 12v 175A has such diodes. This should result in no more than about 36v transient from a full output load dump. Still, 36v is quite a lot hence why I fitted the tranzorb bank. Or Sterling do a similar thing for more £££s. I would caution against the hybrid system (lead acid in parallel) since it seems that for some reason, BSS are dead against it and at some point in the future this might become problematic.

Looking at the Wakespeed docs, there is an option to shut it down from a relay or similar so a BMV could be arranged to stop it an any desired state of charge? So as long as the BMV stays in synch there should be no need for the battery BMV to ever do an emergency disconnect so no real need for the lead acid buffer.

 

Its interesting that for many years much of this forum has said never mix old and new batteries, but many are now happy to put a lead acid into a hybrid Lithium system with the great liklihood that one day that will be an old lead acid in a relatively unaged lithium system, and no easy way to detect the state of health of that lead acid.   Transorbs look like a better approach to handling the surge voltage, but won't solve the problem of the lights going out 😀

[nicknorman]

4 minutes ago, dmr said:

Looking at the Wakespeed docs, there is an option to shut it down from a relay or similar so a BMV could be arranged to stop it an any desired state of charge? So as long as the BMV stays in synch there should be no need for the battery BMV to ever do an emergency disconnect so no real need for the lead acid buffer.

 

Its interesting that for many years much of this forum has said never mix old and new batteries, but many are now happy to put a lead acid into a hybrid Lithium system with the great liklihood that one day that will be an old lead acid in a relatively unaged lithium system, and no easy way to detect the state of health of that lead acid.   Transorbs look like a better approach to handling the surge voltage, but won't solve the problem of the lights going out 😀

Yes I think the BMV relay turning off the wakespeed would be a fairly effective system. You would lose “float” ie keeping the alternator working at a reduced voltage, but that is not a showstopper. You would just have a switch to break the signal, ie stop the alternator shutting down, when you wanted to charge to 100% to sync the BMV

[dmr]

5 hours ago, nicknorman said:

Well you can of course do PID with analogue electronics, it’s just so much easier to do it with digital. The chip I use only starts to decrease current when within about 100mV whereas a conventional alternator regular the same thing is more like 0.5v or maybe more. I would imagine that both the wakespeed and Alpha Pro have digital regulation at their hearts.

I have designed an analog PID position control system in the distant past. It did some very odd things. It would setlle with a slight error (due to friction) and then do a nudge as the "I" term integrated that small error enough to get it moving again.

 

An alternator controller is to some extent a sampled data system because of the voltage ripple. A modern system will sample the voltage at the same point in the ripple cycle. I think you made a good choice in getting a chip to do the voltage control. The Wakespeed needs a phase input, maybe just for speed or maybe for voltage sampling.

 

Adverc shave the numbers off all of their chiips so I don't really know whats inside it.

 

A good approach might be to get a Wakespeed and BMV now to work with the Trojan bank, learn all about them, and then move to Lithium when the Trojans need replacing.

[PeterF]

2 hours ago, nicknorman said:

..... I would caution against the hybrid system (lead acid in parallel) since it seems that for some reason, BSS are dead against it and at some point in the future this might become problematic.

Yes, the potential upcoming unknown changes are an issue.

 

I was reading some stuff on Nordkyn Design who appear to be knowledgeable. Taking one extract from the page I link to below

 

The simplest safe lithium installation: leaving a sealed lead-acid battery in parallel with the lithium bank at all times allows disconnecting the lithium capacity in case of problem without any issues. The additional SLA doesn’t contribute to any meaningful capacity; its function is ensuring charging sources always see a battery in circuit.

 

https://nordkyndesign.com/electrical-design-for-a-marine-lithium-battery-bank/

[BEngo]

IIRC the Wakespeed, in it's original guise,   was open source and all the information and code is still out there.  That should make getting a deep understanding of if a bit easier.

 

N

[dmr]

16 minutes ago, BEngo said:

IIRC the Wakespeed, in it's original guise,   was open source and all the information and code is still out there.  That should make getting a deep understanding of if a bit easier.

 

N

Looks like you are correct, thanks. Looks like the hardware and software were both available and that it was initially based on an Arduino but moved to something bigger and better. Went "private" in 2019.

53 minutes ago, BEngo said:

IIRC the Wakespeed, in it's original guise,   was open source and all the information and code is still out there.  That should make getting a deep understanding of if a bit easier.

 

N

After a quick bit of www......

This was a project from a full time liveaboard in America. One of several projects. Although open source (hardware and software) it was down to one man rather than a team. It sounds like he had no great past expertise in alternator controllers but rapidly became quite an expert. It was originally Arduino based but moved to something with more power.

Balmar were taken over by some sort of investment company and their main marketing man (who was probably not happy about this) suggested starting a new company to comercialise this controller and this became Wakespeed.

[nicknorman]

3 hours ago, dmr said:

I have designed an analog PID position control system in the distant past. It did some very odd things. It would setlle with a slight error (due to friction) and then do a nudge as the "I" term integrated that small error enough to get it moving again.

 

An alternator controller is to some extent a sampled data system because of the voltage ripple. A modern system will sample the voltage at the same point in the ripple cycle. I think you made a good choice in getting a chip to do the voltage control. The Wakespeed needs a phase input, maybe just for speed or maybe for voltage sampling.

 

Adverc shave the numbers off all of their chiips so I don't really know whats inside it.

 

A good approach might be to get a Wakespeed and BMV now to work with the Trojan bank, learn all about them, and then move to Lithium when the Trojans need replacing.

The chip I use also has a phase input, it’s used for various things including rpm awareness, keeping any tacho drive alive (by not reducing field current too much) and it’s state machine ie when power is applied to the “turn on” terminal, just a small field current is supplied until rpm is sensed and only then is full field current (or whatever the programmed limit is ) authorised.

2 hours ago, dmr said:

Looks like you are correct, thanks. Looks like the hardware and software were both available and that it was initially based on an Arduino but moved to something bigger and better. Went "private" in 2019.

After a quick bit of www......

This was a project from a full time liveaboard in America. One of several projects. Although open source (hardware and software) it was down to one man rather than a team. It sounds like he had no great past expertise in alternator controllers but rapidly became quite an expert. It was originally Arduino based but moved to something with more power.

Balmar were taken over by some sort of investment company and their main marketing man (who was probably not happy about this) suggested starting a new company to comercialise this controller and this became Wakespeed.

I did see the circuit, it was very complicated with lots of analogue stuff, op amps etc. as well as the microcontroller. Seemed a huge lot of hassle when you could get a single chip device to do all that and more for £8, hence my strategy (mainly because I’m not great at analogue electronics)

3 hours ago, dmr said:

I have designed an analog PID position control system in the distant past. It did some very odd things. It would setlle with a slight error (due to friction) and then do a nudge as the "I" term integrated that small error enough to get it moving again.

 

An alternator controller is to some extent a sampled data system because of the voltage ripple. A modern system will sample the voltage at the same point in the ripple cycle. I think you made a good choice in getting a chip to do the voltage control. The Wakespeed needs a phase input, maybe just for speed or maybe for voltage sampling.

 

Adverc shave the numbers off all of their chiips so I don't really know whats inside it.

 

A good approach might be to get a Wakespeed and BMV now to work with the Trojan bank, learn all about them, and then move to Lithium when the Trojans need replacing.

On the ripple thing, I find there isn’t any. The BMS chip reads cell voltages to 3 decimal places and the sample time is tiny compared to alternator frequency. There is no detectable ripple. Which is perhaps odd but then again the Combi has chunky electrolytics. But probably mainly because the BMS AtoD cell voltage inputs have 0.1uF and 10k ohm time constant, which is 0.001 seconds / 1000hz.  The alternator chip has similar (no time constant specified, it just says “low pass filter) and one needs to remember that the inductance of the field winding means the field current can’t change quickly and so one might as well have a similar time constant on the voltage measurement.

Edited September 21, 2023 by nicknorman

[MtB]

2 hours ago, dmr said:

Balmar were taken over by some sort of investment company and their main marketing man (who was probably not happy about this) suggested starting a new company to comercialise this controller and this became Wakespeed.

 

That's interesting because there was a firm back in the day IIRC called Wakespeed that did engine tuning, chip design etc for rally cars, and I always imagined the Wakespeed LFP controller was them branching out.

 

But apparently not! 

 

 

[matty40s]

22 hours ago, n-baj said:

 

There’s also an app which connects to the battery bms via Bluetooth (see attached pics)

I am being told that you cannot control/change settings on the BMS, even using the app, as Fogstar will not give the password out. This is ok for 12v system in parralel, but for a 24v system causes problems balancing the batteries. 

[n-baj]

On 22/09/2023 at 12:22, matty40s said:

I am being told that you cannot control/change settings on the BMS, even using the app, as Fogstar will not give the password out. This is ok for 12v system in parralel, but for a 24v system causes problems balancing the batteries. 

That is right, the only thing I can do on the app is turn charging and discharging off and on, the app is really just to monitor.
 

I’ve never felt the need to change the bms settings but I get the impression that if I wanted to then I contact Fogstar and explain the reason why I need to change the settings to keep the warranty. I imagine they will eventually give out the password if they get pestered enough but they will state that the warranty will be invalid in that case.