magnetman
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Posts posted by magnetman
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I was confused when you said 'it was honour and offer'. Did 'it' have gender assignment issues.
Being rather naive around this I had assumed it was a 'he' in this situation but I can see your use of the word 'it' may be more PC in these times of gender fluidity.
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2 minutes ago, Alan de Enfield said:
She offered her honour, he honoured her offer, and all night long it was honour and offer.
1 hour ago, magnetman said:She offered her honour, he honoured her offer and all night long he was on her and off her.
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Radio Spares seem to think there are safety considerations
https://uk.rs-online.com/web/c/power-supplies-transformers/voltage-converters/dc-dc-converters/
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DC-DC Converters
Isolated DC-DC converters convert a source of direct current (DC) from one voltage to another and contain an electrical barrier between the input and output to improve safety. They are suitable for a range of applications, including telecommunication equipment, industrial equipment, and consumer electronics.
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I once heard about an experiment done with cyclists and joggers.
can't remember exactly how it went but it was something like staging a violent and noisy fight between two people beside the path then stopping the cyclist or jogger a bit further on and asking them if they had seen anything unusual. Apparently most of them said they did not notice anything.
Too much attention taken by the task in hand.
I once had a pair of idiot joggers going along the towpath they could see we had a toddler walking beside us but they carried on running and one of them ended up having to partially jump over the child, fell over and had a pained look as if she had sprained her ankle.
Why not just slow down and walk past the obvious hazard ?
Is it thick people or just the workload required to maintain the activity means they can't multitask?
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Some Boats have insulated return alternators. Also not all Boats are metal.
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I got wires crossed. I bet its more durable but the lack of the app control would be a mark against.
For the purposes being discussed anyway.
36 minutes ago, Tony1 said:Well I do declare. The poor B2B would be on and off all night.
Victron better get their act together or there'll be a warranty claim on their hands.
She offered her honour, he honoured her offer and all night long he was on her and off her.
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I see it is the Orion 50 not the Orion 50XS. My mistake !
Not one of their blue box offerings
- Programmable on/off can be from a built in vibration sensor or a programmable input (D+, CANbus or (+)15 connection
Very similar name but the XS is cheaper.
2 hours ago, magnetman said:The orion 50 seems to have a vibration sensor so it goes on and off with the engine.
Actually technically correct in this particular situation but not the product being discussed
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2 minutes ago, IanD said:
Dunno where you got that idea from, it's not in the manual -- engine run/stop detection is either via input voltage or a switched power connection (engine run)...
Google
it has a vibration sensor.
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I had an electric tap once. It was rubbish.
Electric chairs are much better.
Its just easier to get unwanted guests to wash their hands.
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1 hour ago, Tony1 said:
If someone was to throttle a ferret- just as a hobby, say- is the B2B sensitive enough to pick up that sort of vibration?
A friend was asking.
He wouldn't want the B2B switching on every time he offed one of his wee beasties.
Victron will have surely thought of that.
I wondered if they had considered that diesel heaters like the neverspacher often get installed in engine bays.
Windy nights with poor fendering.
Ladies and gentleman activities.
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2 minutes ago, IanD said:
The vast majority of boats round here moored online don't move much, don't have washing machines, don't have shore power, and run either their engine or generator regularly for hours in winter to keep their batteries charged. If they could afford to switch to LFP they'd probably halve generator/engine running time.
AGM still have most of the same problems as standard LA, they just cost more and -- if treated properly -- last longer. If not treated properly they still die an early death, as many boaters have found... 😞
It was @David Mack who said he might reluctantly buy lead acid. We are not talking about 'most of the Boats' I was referring to a comment by a single contributor.
I'm not arguing about whether lithium is better. It obviously is but it is not the only valid option for a Boat which is used for Boating such as a historic might be.
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Some of the earlier Teddesley Boats were built by at Allens of Oldbury* and are very high quality if ageing narrow Boats.
Built for their hire fleet.
* ETA correction not quite right.
From the Allens register
Horton Boats-
A section on boats built by John Horton who worked at the yard leaving just before the yard closed. After leaving John firstly built shells at Teddesley for the hire fleet, then moved to Oldbury Boat Services where he built a number of boats for private customers. John moved again to larger premises away from the canal where he built a number of boats until he to retired in about 2006. All of his boats look like Allens because thats the way he learn't to build them at the Allens. He stamped his own identity on them but they nevertheless continiued the classic shape for a few years after the Allens stopped.I had an Allens Boat once. One of the best.
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15 minutes ago, IanD said:
Nothing to do with being set up like an apartment -- of course LA do the job, but you have to run the engine for hours to get them fully charged/equalised as current falls off and prevent sulphation if you don't want them to die an early death.
LFP accepting full current up to 100% SoC and then stopping -- plus higher cycle efficiency -- means maybe half the engine running time and wear and less fuel burned, which is why a lot of boaters are fitting them even in non-apartment boats... 😉
Some people run their engines for several hours while moving the Boat and don't have washing machines. The Boat may well be on mains power when not being used.
Yes lithium batteries are a lot better but -depending on how one uses the Boat- decent AGM is still a valid option. Particularly for someone who has an alternator which is currently doing nothing. This seems to indicate a low energy consumer or maybe an unfinished Boat.
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The orion 50 seems to have a vibration sensor so it goes on and off with the engine.
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In the specs it is written non isolated for the Orion 50 but not written on the blue casing.
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The Orion XS 50A is non isolated. The 30A version is isolated.
BuckBoost 50 is the previous name of the Orion XS 50A.
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1 hour ago, David Mack said:
Well currently I have nothing bar an unconnected alternator on the boat. So it's a reasonable question what to install.
But the choice seems to be between a costly professional install, a simple DIY hybrid system with a long bit of wire, getting up to speed with some sort of self-developed electronic control system or sticking with lead acid, the 2nd and 3rd options apparently falling foul of battery manufacturers' instructions, relevant standards and insurance requirements. Hence, slightly reluctantly thinking of heading down the LA route.
Incidentally, have any of the hire boat firms gone down the lithium route, or are they all sticking with tried and tested technology, widely understood and easily fixed if something goes wrong?
Victron AGM batteries are very good quality. Not cheap but if you don't want to do lithium because it is complicated AGM is still a valid solution specially for a Boat which is cruising rather than moored when occupied.
Obviously being able to cram in as much charge as possible in a short time is desirable for someone who moors for two weeks then moves because the law says they should.
For someone whose Boat tends to be moving for several hours per day the advantage is less significant.
People always used to do OK with lead batteries and they can still do the job on a Boat which is not set up like an apartment.
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The Victron 50A B2B does look good to be fair as it seems to allow user settings for charge profile and current.
Quite attractive. Easy enough to have an alarm for alternator case temperature.
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17 minutes ago, cheesegas said:
This would make it possible to severely damage the battery by trying to start the engine when the battery is discharged and the BMS is about to do a discharge disconnect. It’s also the most likely time that someone’s going to start the engine - leisure battery low, need to run engine to charge batteries.
The timer would work for a lead battery but not lithium, and it would still be a bad solution. Say you’ve worked out that you need to put in 100ah with your 100a alternator, which works out to 1hr. Then, you go inside, switch the inverter on, charge your laptop and put on the washing machine…this all takes say 20ah so you end up with only 80ah in the battery. And if you were to start the engine in summer at 3pm to cruise, you’d need to check that the alternator is off or else you’d be holding the lithium battery at full charge which isn’t good for it.
A better solution which is what myself and a couple others do on here is to use the relay output on a Victron BMV to disable the alternator at 100%. This is better but not great - without a float voltage, if you were to draw high power with the batteries full and alt off, it goes into a loop of short charge, short discharge and repeat.
LTO is an interesting option. I have been experimenting with 6S LTO modules and they don't seem to be bothered about much. I've had one of them down to about 4v (no BMS) and it charged up normally cells are still within 3mV of each other.
Also the top voltage is 16.8v. Mid range maintenance voltage between 14 and 15v.
Not done any alternator testing its just been solar so far but I will be doing some experiments.
Also excellent for engine starting I use a 40Ah module charged to 15.2v to start the Perkins P4 its does it happily.
They are generally rather expensive batteries but if one were to have a multi cycle charge discharge regime the battery banks can be smaller.
I have marked the module which went right down (lights left on) and interesting to see if it suffered at all. It appears not.
LTO have very high cycle life and also huge C rating. 10C is easy.
i took apart a Suzuki Swift mild hybrid battery. It has a 3Ah 5S LTO battery which is nominal 12v 3Ah. Tiny. The battery has a 150A fuse despite being so small. This is used in the car to add power while moving from a standstill then recharged. I believe the in/out rate is probably something like 20C in use which would mean it was supplying nearly 1HP for a short time.
It might be more. The 150A fuse was interesting.
Yes 6S is a bit high for normal 12v loads but easy to put a buck converter on lights and pumps circuit. Inverters cut out at over 15v which is about 85% charged so a happy battery.
LTO ocv soc graph . So roughly 40-90% is 2.2-2.5v which for a 6S would be 13.2-15v. Not too terrible. Space above for safety.
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24 minutes ago, cheesegas said:
The issue with a lithium starter battery is that most BMSs are rated for 100-200 amps, whereas the starter motor can draw 300+ amps. You'd need either a contactor based BMS, or massive FETs to pass the current. It's fairly common in the cafe racer motorcycle scene as their starter motors draw a lot less current.
Most alternators we see on boats at the moment are based on car designs, which have no need to adapt to lithium batteries - it's only marine-specific models like Balmars etc which have lithium compatible regulators, and those are expensive external ones. You'd usually see Balmars on dual engined cruisers with a big house battery bank. I think the market is very small for an alternator with an internal lithium regulator so it'll be many years before one comes out.
There are however some large non-automotive alternators aimed at the modified car market with massive audio systems - they're built very well to withstand heavy loads at a low engine speed so it would be good to see them adapted for marine use. Some even have remote rectifiers and regulators to keep the heat in the case down. Again though, not cheap as the market is pretty small!
It would be very easy to have two negative terminals. One attached to the BMS for loads which may discharge the battery while unattended and the other one for heavy discharge such as starter motor and connected directly to the terminals.
I have a battery like this.40A BMS or connect direct. It was home made by someone who is an EV industry professional. Seems an interesting approach I think.
5 minutes ago, Alan de Enfield said:Why not ?
If a small market wants (needs) something they have to pay the design, set up and low volume production costs amortised over a small number of customers.
Yes that is basic economics but if lithium batteries become universal then it seems demand would go up.
Is it not plausible just to have say a 65A alternator which will charge a LFP battery and switch itself off after a certain amount of time? If one knew how many Ah one wanted would it not make sense to put a timer onto the regulator.
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I wonder how many others use lithium batteries for starting the engines.
Alternators do need to adapt to lithium batteries at some stage and it should not mean a regulator costing hundreds of pounds.
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Is there any reason why the MPPT would object to a voltage which was not jumping around? Presumably with solar panels with no shade and a sunny day this would be quite a common outcome.
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I have endless room in my head for batteries.
I suppose people do have space constraints which is why the drop in thing exists in the first place.
One day these problems will be solved when infernal combustion engines are banned.
1 minute ago, Alan de Enfield said:MPPT fed by 24v alternator ?
See above
33 minutes ago, magnetman said:Maybe A 24v alternator, 2 LA batteries to make a 24v bank and the MPPT repurposed for winter to charge the LFP batteries via alternator-LA battery-MPPT.
In summer the solar does the job and the other alternator is still 12 volts.
33 minutes ago, IanD said:I'm not sure using an MPPT controller as a B2B is a good idea, the nature of the beast is different -- an MPPT controller is expecting to have solar panels on the input, and to adapt the input current and voltage to maximise output power from the panels. Not sure how this will react when the input side is an LA battery being charged by an alternator, maybe it'll just provide maximum output current all the time...
Its an interesting question.
i wonder if it is good for the makers (lets say Victron) to keep these two products separate in order to shift more blue items in flash boxes. They might be electronically very similar. I don't know but have difficulty working out why the output from an alternator through a battery would be so different from a solar panel.
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24v Alternator 55A is £150 (prestolite lucas a127)
Couple of cheap lead acid batteries £150.
I already have a 50A MPPT which is surplus in winter. In summer the vast majority of the electric is dealt with by solar panels.
50A b2b would be £300.
It costs the same. I think the 24v alternator might be better for thermal management as there are fewer amps coming out of it.
Which would mean one could eke out more power with less risk of overheating.
I expect a good alternator controller solves these problems but how much do they cost?
Lithium Batteries installation
in Boat Equipment
Posted
So why does the Victron 30A B2B have an isolated option but the 50A version doesn't?
It can't be an oversight because the 30A version is available with or without.
If anything one could think that the higher current device might want it more than the lower current device.
Is it something which adds to the cost significantly ?