Drop in Lithium Batteries - the basics?

[shanemax]

Google Lithium Batteries and Airlines by the International Air Transport Association. I dare say such an organisation, which represents every airline in the world have not bothered to do their research.properly. You are talking rubbish and I dare say a person like you will not Google what i suggest but will carry on with your head under the sand.

 

[B27]

How much engine charging do you actually need?
The bigger the DC-DC charger, the bigger the wiring, the more heat to get rid of.

Indeed.
Hard to quantify the exact benefit of 'more is better'.
I can only estimate that on a typical cruise, if there's nice sailing breeze I might want to shove in say 30Ah in as little as 40 minutes of motoring, If running the engine for a bit longer saves me hundreds on a B2B, I'm likely to go for a smaller B2B which will be adequate on maybe 3 cruises out of 4?

 

[B27]

Google Lithium Batteries and Airlines by the International Air Transport Association. I dare say such an organisation, which represents every airline in the world have not bothered to do their research.properly. You are talking rubbish and I dare say a person like you will not Google what i suggest but will carry on with your head under the sand.

I regularly fly with my lithium powered phone and laptop.
I don't think they'd let me on the plane with a big lead/acid battery.

 

[Poey50]

Google Lithium Batteries and Airlines by the International Air Transport Association. I dare say such an organisation, which represents every airline in the world have not bothered to do their research.properly. You are talking rubbish and I dare say a person like you will not Google what i suggest but will carry on with your head under the sand.

Best to keep quiet, now. Kelpie is correct.

 

[shanemax]

Hand luggage is fine as the crew are trained( and have to be as lithium fires are becoming more common) to handle phones, laptops etc. Now Sadler, instead of being rude from a distance, which tells me alot about you, Google the site I refer to and then give me your answer. I suppose they are wrong and you are right. Best you get in touch with the International Transport Association and tell them they have got it wrong.

 

[Kelpie]

Google Lithium Batteries and Airlines by the International Air Transport Association. I dare say such an organisation, which represents every airline in the world have not bothered to do their research.properly. You are talking rubbish and I dare say a person like you will not Google what i suggest but will carry on with your head under the sand.

Which bit of my post is talking rubbish?

I do not in any way disagree with you about whether you can take a lithium battery on a plane. My wife recently flew long haul and brought me back a new Makita battery, and I already checked to make sure of the rules around that. Her airline allowed her to take a battery of up to 100kwhr in hand luggage only.

IATA will also not let you take a gallon of petrol or a large lead acid battery on a plane either. Yet we routinely carry these things on our boats.

 

[dgadee]

Worry not! I will buy batteries in Greece!!

 

[dgadee]

How much engine charging do you actually need?
The bigger the DC-DC charger, the bigger the wiring, the more heat to get rid of.

I don't suppose I need a lot in Greece with solar panels in operation but we are intending to slowly return home.

I have a vision of my slternator outputting electrons and they have nowhere to go. But - thinking about it - the slternator will just reduce output. And if it does that will it take less hp?

 

[Kelpie]

I don't suppose I need a lot in Greece with solar panels in operation but we are intending to slowly return home.

I have a vision of my slternator outputting electrons and they have nowhere to go. But - thinking about it - the slternator will just reduce output. And if it does that will it take less hp?

Hopefully somebody else who takes engine charging seriously can answer, but my understanding is that most alternators can't output their rating continuously without overheating. Both the alternator and the DC-DC will generate a lot of heat, and that's where some of your hp will end up.

One advantage of the Sterling units is that they have a half power mode, although they don't seem as easy to use as the Victrons.

 

[dgadee]

Of course, the elephant is the watermaker run off the inverter. Almost forgot that. A B2B system or larger lithium would be the two options?

I do like your practical approach, Kelpie!

 

[Kelpie]

Of course, the elephant is the watermaker run off the inverter. Almost forgot that. A B2B system or larger lithium would be the two options?

I do like your practical approach, Kelpie!

No point adding more lithium if you're taking out more power than you're putting back in.
If you need to run the engine to keep up with demand from the watermaker, I'm not sure that a DC-DC is the most efficient way of doing that.

 

[rogerthebodger]

Of course, the elephant is the watermaker run off the inverter.

One of the things you need to consider with single phase motors is the inrush current with direct on line starting.

Have a look at variable speed motor inverters that can vary the frequency to adjust the speed of the motor and the reduce the instant current draw with a DOL motor starter

Variable speed 3 phase inverters are more common then single phase inverters and may be more cost effective to go 3 phase

 

[dgadee]

One of the things you need to consider with single phase motors is the inrush current with direct on line starting.

Have a look at variable speed motor inverters that can vary the frequency to adjust the speed of the motor and the reduce the instant current draw with a DOL motor starter

Variable speed 3 phase inverters are more common then single phase inverters and may be more cost effective to go 3 phase

I bought a low power start up motor and it has worked well for 3 years with the Honda and the 2kw inverter. I also have a three phse motor and invertor to control it but have not changed over. I made the mistake of buying a US pump and the motor frame had to suit, so that was a hassle to overcome.

Like all of these things you often become expert after making mistakes.

Which is why I want to get the lithuium system worked out before I purchase.

 

[B27]

Hopefully somebody else who takes engine charging seriously can answer, but my understanding is that most alternators can't output their rating continuously without overheating. Both the alternator and the DC-DC will generate a lot of heat, and that's where some of your hp will end up.

One advantage of the Sterling units is that they have a half power mode, although they don't seem as easy to use as the Victrons.

What an alternator can do will vary.
I don't even know who made the alternator on my Beta.
Will it shut down if it overheats, or will it fail?

If you over load it, will it limit current to its design value or just put out fewer volts?

How hot it gets will depend on how hot the air is in the engine box, the air flow through the alternator and the current it's delivering.

Boat engine alternators are like car alternators from about 20 years ago. Mostly they are intended for plant which runs continuously. When Kubota choose an alternator, they probably expect it to be connected to a starter battery with some loads like lights and motors drawing from it. They probably don't ask it if will be happy with a huge B2B or inverter strapped to it.
People don't generally have alternator problems when running big loads like thrusters and windlasses, but these are normally short durations.

It's common to de-rate stuff for either continuous operation, or high ambient temperature.
We don't seem to have all the information you'd need to do a professional job.

 

[Tranona]

Boat engine alternators are like car alternators from about 20 years ago. Mostly they are intended for plant which runs continuously. When Kubota choose an alternator, they probably expect it to be connected to a starter battery with some loads like lights and motors drawing from it. They probably don't ask it if will be happy with a huge B2B or inverter strapped to it.
People don't generally have alternator problems when running big loads like thrusters and windlasses, but these are normally short durations.

Beta fit alternators appropriate to the type of application the engine is aimed at. Up to 25hp, 40amp, 30-43hp 70amp. Larger are options on the whole range, either 70amps for the small engines and 120amp for all. Above 43hp there is no standard but a wide range of options including second alternators.

It is pretty clear from all the discussions that the value of lithium really comes if you are not reliant on the alternator alone for charging - or even not at all. So, no reason for having a super large output for charging lithium as it is more appropriate to avoid charging direct from the alternator

 

[noelex]

It is pretty clear from all the discussions that the value of lithium really comes if you are not reliant on the alternator alone for charging - or even not at all. So, no reason for having a super large output for charging lithium as it is more appropriate to avoid charging direct from the alternator

Lithium can work better than lead when charging via an alternator. The high acceptance rate of lithium until almost 100% full means more charge can be squeezed into the battery bank with only a short amount of motoring. This is a significant advantage.

The drawback is a more sophisticated and expensive system is needed, although these steps are also used on some larger lead acid systems.

If you want to keep things simple and inexpensive this can be done with lithium, for example by incorporating a battery to battery charger. This can be a good solution, but this generally results in a lower charge rate and a more complicated and expensive system than with a simple lead acid system, leading to the somewhat misleading impression that lithium batteries cannot work well with alternator charging.

 

[B27]

Lithium can work better than lead when charging via an alternator. The high acceptance rate of lithium until almost 100% full means more charge can be squeezed into the battery bank with only a short amount of motoring. This is a significant advantage.

The drawback is a more sophisticated and expensive system is needed, although these steps are also used on some larger lead acid systems.

If you want to keep things simple and inexpensive this can be done with lithium, for example by incorporating a battery to battery charger. This can be a good solution, but this generally results in a lower charge rate and a more complicated and expensive system than with a simple lead acid system, leading to the somewhat misleading impression that lithium batteries cannot work well with alternator charging.

Indeed.
Sometimes, it's not sunny, there is no shore power and you don't run the motor for long periods.

Being able to a) stuff in a useful amount of charge quickly
and b) not have to worry about leaving the battery part-charged
is quite attractive.

ISTM all that's actually required is to limit the charging current to a value both the alternator and the battery (and its inbuilt BMS) are happy with. That might be possible with a fairly simple FET circuit.

 

[mattonthesea]

We have a sterling b2b. We have it on half power because the fan is very loud on full power. Not noticed when engine running but cor when first charging from shore power. Once we have full solar complement we will go full power again.

Yes programming it is a bit like setting an electric cooker. Press button A with your hand on your hip while tapping Bolero on button B sort of thing.

 

[noelex]

ISTM all that's actually required is to limit the charging current to a value both the alternator and the battery (and its inbuilt BMS) are happy with. That might be possible with a fairly simple FET circuit.

A very basic approach such as this may work, but ideally a few more parameters need to be controlled. The charging voltage is particularly important for lithium. The dumb regular built into the alternator is not suitable for this.

An external alternator regulator will control the voltage and modulate the output based on the alternator temperature. This allows the maximum energy to be extracted without damaging the alternator.

You also need a system to protect the alternator if the BMS decides to disconnect the battery while the engine is running.

 

[B27]

A very basic approach such as this may work, but ideally a few more parameters need to be controlled. The charging voltage is particularly important for lithium. The dumb regular built into the alternator is not suitable for this.

An external alternator regulator will control the voltage and modulate the output based on the alternator temperature. This allows the maximum energy to be extracted without damaging the alternator.

You also need a system to protect the alternator if the BMS decides to disconnect the battery while the engine is running.

Hardest part of all that is probably knowing what temperature the alternator can cope with and how to measure it. Do we need to measure the diodes, the windings or what?
If the current and volts are in correct limits, the BMS should not switch off, but give or take a few zeners, transorbs etc, the alternator should be happy just seeing the starter battery.

This kind of thing is going to have the charge current tailing off quickly somewhere near 90% SOC, (maybe 85% with achievable voltage losses?) which doesn't seem too bad a place to give up on the alternator and leave things until the solar tops it up.

It won't work if your alternator can't deliver a genuine 14.4V on load.
I've seen a lot less than this on older boat alternators, because 14.4 is a good voltage for a car which gets used one hour a day, not so good for a generator or digger intended to run 8 hour shifts.
So if you don't have the source volts and add in some cable resistance etc, it probably goes to rats'.

Also the '14.4V DC' output of the alternator is probably a dirty spiky mess which may upset the BMS.
If the BMS is designed to work in some pretty narrow use-cases based on mains and solar chargers, there's no guarantee when you show it an alternator.

Maybe they sell us expensive B2B solutions for a reason then!