Is it possible?

[T1 Terry]

I have no idea where you came up with the idea that every thing has to be replaced in the charging system if you go from lead acid batteries to lithium batteries.
You might need to upgrade cheap unrealistically rated charging equipment that may say perhaps 50 amps capability but in real life they can only handle that output for 20 mins at best. These generally have a battery capacity listed in the specs, they rely on the fact lead acid batteries can only handle so much fast charging before the terminal voltage rises to the point the charger throttles back the current to maintain the charging voltage.
Because quality lithium batteries will accept all you can throw at them and more, these cheap charging devices overheat and fail ..... it isn't that they are not lithium rated, it is that they are not actually capable of a 100% duty cycle at the output rate they claim on the label.

If you have a proper BMS system, the charger is controlled by the BMS, not what ever program the manufacturer put in there to claim they are lithium chargers. A decent charger has a function the user can program, either via a touch screen or a smart phone or it might need a patch cord to a laptop in some cases.

No idea where you came up with the idea a DC to DC charger was a lot more expensive than a pure sine wave inverter and battery charger would cost.
The battery charger that works from the generator is already built into the main inverter, why double it up with a second charger?

If the alternator can handle an inverter draw that is rated at 80% of the labelled capacity, why couldn't a DC to DC charger do the same job, far more efficiently and have all the safety features programmable in it to protect the alternator and start battery from being over worked?
Every one of the systems I've installed that also used a DC to DC charger, later sold their generator because they were only carrying it around for other people to use ......

You are trying to build a work around for a problem that doesn't exist ......

T1 Terry

[SOLAR SUPPORT]

Originally Posted by T1 Terry

I have no idea where you came up with the idea that every thing has to be replaced in the charging system

This idea you're talking about isn't mine, you're definitely confusing it. My thought and plan was born for the opposite purpose. This is an alternative and very economical plan for those who are just planning to make the transition rather than those who have already done the LA - LFP upgrade.

if you go from lead acid batteries to lithium batteries. You might need to upgrade cheap unrealistically rated charging equipment that may say perhaps 50 amps capability but in real life they can only handle that output for 20 mins at best. These generally have a battery capacity listed in the specs, they rely on the fact lead acid batteries can only handle so much fast charging before the terminal voltage rises to the point the charger throttles back the current to maintain the charging voltage. Because quality lithium batteries will accept all you can throw at them and more, these cheap charging devices overheat and fail ....it isn't that they are not lithium rated, it is that they are not actually capable of a 100% duty cycle at the output rate they claim on the label. it isn't that they are not lithium rated, it is that they are not actually capable of a 100% duty cycle at the output rate they claim on the label.

Companies that manufacture inverters may not be honest about continuous working power. We do not know this, but; We can expect it to work continuously at 40-50% below the power stated on the label. I think it is known enough that alternators are very inadequate for direct LFP charging.

If you have a proper BMS system, the charger is controlled by the BMS, not what ever program the manufacturer put in there to claim they are lithium chargers. A decent charger has a function the user can program, either via a touch screen or a smart phone or it might need a patch cord to a laptop in some cases.

This is a recommended solution plan for drop-in batteries. It is realy good to see every devivce's current values and performance on the mobile phone, but it is not cheap. I am fond of mobile phones and technology, but I do not feel dependent on them. I wouldn't want to neglect many things that I have to do on the boat by frequently following every device on my mobile phone.

No idea where you came up with the idea a DC to DC charger was a lot more expensive than a pure sine wave inverter and battery charger would cost.
The battery charger that works from the generator is already built into the main inverter, why double it up with a second charger?No idea where you came up with the idea a DC to DC charger was a lot more expensive than a pure sine wave inverter and battery charger would cost. The battery charger that works from the generator is already built into the main inverter, why double it up with a second charger? T1 Terry

If the primary charging source is solar, I recommend the alternator - inverter generator plan as an economical alternative one. I think it should be used when dc-dc charger is needed, especially when the primary charging source is alternator. Because it is important to fill the batteries in a short time. It is certain that dc-dc devices are more efficient than alternator-inverters. Carrying generators for boats with solar energy is now outdated, I agree with you on this matter.
I aim to solve multiple existing problems in an economical way.

.........

[SOLAR SUPPORT]

I ran the alternator-inverter couple on the boat. I connected the existing 1000W pure sine inverter to the alternator. I did not use any other device in the experiment. An AC extension cable was needed only because the inverter output connected close to the alternator and the AC battery charger were some distance away.

The AC current produced by a pure sine inverter is in the form of a sine wave with 3% total harmonic distortion (THD) and is not affected by the alternator speed. AC energy from the land grid has 5%THD. Therefore, any AC device with a power below the AC power produced by the pure sine inverter working with the alternator can be operated. Well, I guessed that EE people would know that. Just like DC-DC chargers, there is a 10-15% loss in pure sine inverter operated with alternator.

If you have an existing AC battery charger on board, you can use this device to charge your batteries. I have explained the points to be considered in detail in my previous post. The calculation I made here is valid. However, the efficiency percentages of the inverter and AC battery charger used may vary for devices of different quality. When calculating, you should consider the efficiency values ​​of these two devices separately and you should not exceed 50% of the highest current value specified on the alternator label.

If your primary energy source is solar energy, you can consider this system. If the alternator charge is used only when necessary and infrequently, such a low-cost scheme can be implemented. Especially if there is an AC battery charger capable of charging all battery groups on a boat with more than two battery groups, it is possible to charge all LFP batteries by using the AC power produced by the alternator-inverter, with the existing battery charging infrastructure, provided that necessary precautions are taken.

The hybrid inverter that I have explained before, which includes solar mppt and AC battery chargers, can also be used in the same way. You can make detailed settings of the chargers that can work integrated with each other in the hybrid inverter, and follow the production and operation of both devices on the hybrid device screen.

If your primary charging source is the alternator, using a DC-dc charger brings 10-15% increase in efficiency. Thus, you run up to 15% less engine to recharge your batteries.

[Franziska]

Question related to this. We have the following setup right now:

2.6 kw continous rated petrol inverter genset producing 220V.
220V AC Outlet of this genset connects to
Waeco 1250 50A charger.

Charger 12V outlet connects to charging busbar (with wind and solar connected to it via their controllers as well).

400A rated Daly BMS connects to the 840Ah LiFePo4 battery.

We use the genset only to top up in case there is not enough sun and manually switch the genset off at 80% charge status. I am aware that the Waeco is not ideal for charging LiFePo4 but as we switch the charger of at 80% I see no issue from that side.

Here is the question I have, is this setup risking damage to the petrol generator?

[goboatingnow]

I do think the future is boat specific hybrid invertors. Hopefully Victron and others will come forward. It’s on my mission list at METSTRADE in two weeks to review what’s on the market or coming

[SOLAR SUPPORT]

Originally Posted by Franziska

Question related to this. We have the following setup right now:

2.6 kw continous rated petrol inverter genset producing 220V.
220V AC Outlet of this genset connects to
Waeco 1250 50A charger.

Charger 12V outlet connects to charging busbar (with wind and solar connected to it via their controllers as well).

400A rated Daly BMS connects to the 840Ah LiFePo4 battery.

We use the genset only to top up in case there is not enough sun and manually switch the genset off at 80% charge status. I am aware that the Waeco is not ideal for charging LiFePo4 but as we switch the charger of at 80% I see no issue from that side.

Here is the question I have, is this setup risking damage to the petrol generator?

Common or inverter type generators must be manufactured in such a way that they can protect themselves in case of sudden power cut. This is a normal operating condition for a generator. A similar situation occurs when the BMS controlling LFP-Li batteries suddenly cuts off the charging current when the batteries are full.

If there is a high consumption at the same time while the batteries are being charged, the BMS, which has stopped charging, will want to continue charging after a short while. If there is no circuit in the BMS circuit or generator that delays this on-off cycle, an undesired on-off cycle may begin. I think it would be more correct to turn off the generator when the batteries reach 80%Soc.

[goboatingnow]

Inverter based generators have control loop responses faster then spike dynamics. Hence there is little issue with abrupt load disconnect.

[Franziska]

Well, for those with the cash for all brand new stuff from high end manufacturers like V. they will probably be, for folks with more modest funds it will take very long till that happens.

[Franziska]

Originally Posted by SOLAR SUPPORT

Common or inverter type generators must be manufactured in such a way that they can protect themselves in case of sudden power cut. This is a normal operating condition for a generator. A similar situation occurs when the BMS controlling LFP-Li batteries suddenly cuts off the charging current when the batteries are full.

If there is a high consumption at the same time while the batteries are being charged, the BMS, which has stopped charging, will want to continue charging after a short while. If there is no circuit in the BMS circuit or generator that delays this on-off cycle, an undesired on-off cycle may begin. I think it would be more correct to turn off the generator when the batteries reach 80%Soc.

Thanks.

The last phrase is exactly what we are doing. We turn the genset manually off at 80%SOC.

So in my above described scenario our genset should have no problem, correct?

[SOLAR SUPPORT]

Originally Posted by Franziska

Well, for those with the cash for all brand new stuff from high end manufacturers like V. they will probably be, for folks with more modest funds it will take very long till that happens.

The prices of Lifepo4 drop-in batteries have decreased to the level of AGM batteries. The advantages of long life, high performance and lightness of Lifepo4 batteries make a difference.

There are many economical ways to use this type of battery. Therefore, lifepo4 drop-in battery usage will increase with solutions that do not shake the budget. Thanks to the newly developed hybrid integrated devices, Drop-in Lifepo4 batteries will increase economical, budget-friendly installations and will create an alternative to quite expensive systems.

LA technology, on the other hand, will probably continue to be used only as an engine battery.

[Franziska]

Originally Posted by SOLAR SUPPORT

The prices of Lifepo4 drop-in batteries have decreased to the level of AGM batteries. The advantages of long life, high performance and lightness of Lifepo4 batteries make a difference.



There are many economical ways to use this type of battery. Therefore, lifepo4 drop-in battery usage will increase with solutions that do not shake the budget. Thanks to the newly developed hybrid integrated devices, Drop-in Lifepo4 batteries will increase economical, budget-friendly installations and will create an alternative to quite expensive systems.



LA technology, on the other hand, will probably continue to be used only as an engine battery.

I was actually referring to post #52.

We are a low budget boat and are all in with LiFePo4, it's much cheaper than FLA these days, especially if you educate yourself upfront enough to assemble the system yourself.
Works good and very reliable so far for us...

[T1 Terry]

Sorry, I posted this yesterday but it must have vanished into the ether.

Originally Posted by Franziska

Question related to this. We have the following setup right now:

2.6 kw continous rated petrol inverter genset producing 220V.
220V AC Outlet of this genset connects to
Waeco 1250 50A charger.

Charger 12V outlet connects to charging busbar (with wind and solar connected to it via their controllers as well).

400A rated Daly BMS connects to the 840Ah LiFePo4 battery.

We use the genset only to top up in case there is not enough sun and manually switch the genset off at 80% charge status. I am aware that the Waeco is not ideal for charging LiFePo4 but as we switch the charger of at 80% I see no issue from that side.

Here is the question I have, is this setup risking damage to the petrol generator?

Hi franziska, if you have a BMS that senses cell voltage and can cut the charging if a cell goes over 3.6v, then adding a "Finder" (https://www.digikey.com.au/en/produc...hoC7V0QAvD_BwE as an example of what I'm talking about) in the 240vac ac between the generator and the charger, it will also work when on shore power to do the same job.
This will stop the charging if the any cell in the battery goes over voltage, it will not damage the inverter/generator and you will hear when the generator is unloaded because the "Finder"has been opened by the BMS, so you can schedule in when you have a moment to turn the generator off.

T1 Terry

[smac999]

Get rid of all that bs.

Alt to start battery. No batt isolator.

StArt battery to victron Orion smart dc to dc. to lith bank. No silly inverters.

The solar / inverter. Whatever stays on lithuim bank. Has nothing to do with alt.

[goboatingnow]

Originally Posted by smac999

Get rid of all that bs.



Alt to start battery. No batt isolator.



StArt battery to victron Orion smart dc to dc. to lith bank. No silly inverters.



The solar / inverter. Whatever stays on lithuim bank. Has nothing to do with alt.

Or as I mentioned dc dc direct from alt to LFp get rid of all that SLA D.C DC BS

[SOLAR SUPPORT]

People can charge their batteries using the AC shore chargers available on their boats. This is a commonly used simple way to safely charge Lifepo4 batteries. To do this, you supply AC power using the shore mains or onboard generator.

Under this heading, I explained that there is a third way to obtain the required AC power as shown in the plan. You can use your pure sine inverter with suitable power just like a generator by connecting it to the alternator output. The important thing to be careful here is not to force the limits of the alternator.

Again, with this plan, you can use the existing fabricated alternator. You can have a system that can safely charge and monitor your drop-in Lifepo4 batteries with a hybrid inverter charger that you can buy by spending $250-300. By following this path, you will be able to upgrade your existing solar mppt controller and AC battery charger with Lifepo4 compatible ones in a short way and economically. Especially for a new system to be installed, is there a more economical and at the same time safe solution?