Is it possible?

[hjohnson]

Originally Posted by SOLAR SUPPORT

The largest area of ​​LA - LFP upgrade projects consists of solutions to problems arising from alternator charging of LFP batteries. You will have to replace the existing alternator on the boat or use a dc-dc charger.

Eh, I had my stock Hitachi 85A modified for external regulation and added a Wakespeed regulator. It works really well, and lets the 85A alternator not overwhelm my little one cylinder diesel.

[SOLAR SUPPORT]

Originally Posted by hjohnson

Eh, I had my stock Hitachi 85A modified for external regulation and added a Wakespeed regulator. It works really well, and lets the 85A alternator not overwhelm my little one cylinder diesel.

If a new electrical installation is not installed or your existing solar and shore chargers can work with LFP batteries, it is sufficient to solve only the alternator charging problem for an LFP battery upgrade.

You can buy the hybrid inverter with 1500 watt pure sine inverter, 40A mppt solar charger and 30A battery charger for $300. All devices are in the same box working in harmony. You can monitor the data of all charging sources and adjust their settings from the control panel of this device.

Add in the cost of the small inverter with 600-800 watts capacity that will work with the alternator which is purchased around $150. The total cost of this small but complete system solution, including the charging solution of the existing alternator, is around $450-$500.

[hjohnson]

Originally Posted by SOLAR SUPPORT

If a new electrical installation is not installed or your existing solar and shore chargers can work with LFP batteries, it is sufficient to solve only the alternator charging problem for an LFP battery upgrade.

You can buy the hybrid inverter with 1500 watt pure sine inverter, 40A mppt solar charger and 30A battery charger for $300. All devices are in the same box working in harmony. You can monitor the data of all charging sources and adjust their settings from the control panel of this device.

Add in the cost of the small inverter with 600-800 watts capacity that will work with the alternator which is purchased arround $150. The total cost of this small but complete system solution, including the charging solution of the existing alternator, is around $450-$500.

You can, yes, but those $300 integrated units tend to be 100% pure chinesium junk, and completely unsuitable for the marine environment. On a boat, there is little margin for error, especially when it comes to things that have the potential to burn your boat down. Unsafe and uncertified equipment has no place on a boat.

On my boat, I literally sleep on top of my power system. It’s installed, battery and all, in the lockers under the berth I normally sleep in. I like sleeping well at night.

[T1 Terry]

Originally Posted by SOLAR SUPPORT

If a new electrical installation is not installed or your existing solar and shore chargers can work with LFP batteries, it is sufficient to solve only the alternator charging problem for an LFP battery upgrade.

You can buy the hybrid inverter with 1500 watt pure sine inverter, 40A mppt solar charger and 30A battery charger for $300. All devices are in the same box working in harmony. You can monitor the data of all charging sources and adjust their settings from the control panel of this device.

Add in the cost of the small inverter with 600-800 watts capacity that will work with the alternator which is purchased around $150. The total cost of this small but complete system solution, including the charging solution of the existing alternator, is around $450-$500.

I'm very confused now, but that isn't all that unusual :lol: Are you hoping to power an inverter charger from another inverter via the 240vac input? The chances of getting that to work using a cheap inverter are close to nil, the sine wave pattern and voltage stability isn't good enough for the inverter/charger to accept it as clean power and will just ignore it. There are enough problems with even Onan gensets not having clean enough power for the inverter/chargers to accept, the output need to be as close to pure sine wave and stability as a load is applied as what you get from good shore power, they won't even accept shore power that isn't clean and stable.

Output from the likes of a Victron inverter is clean enough, but you aren't going to get one of those at the prices you are quoting, and remember inverter/chargers automatically switch the AC load to the input AC when they sense and connect to the AC input ..... so a big inverter would be required and that defeats the whole design.

A modified sine wave inverter powering a cheap 240v to 12v charger that isn't a transformer type, but in the long run as far as cost and reliability, a quality DC to DC charger will solve a whole host of problems you haven't even recognised yet.

T1 Terry

[SOLAR SUPPORT]

It is a reality that the costs of hybrid inverter devices available in the market are quite low. Before underestimating Chinese technology, it is necessary to test the working safety and capacity of these inexpensive devices. Of course, it is important to be aware of the destructive effect of the marine environment on all kinds of devices containing metal.

Instead of using cables and plug connectors to assemble devices with specific functions separately and to connect them with each other, combining them on a main board and producing them in a single box to work integrated with each other means reducing the disruptive effect of the marine environment.

The idea of ​​using an inverter for direct use of the existing alternators on board results in the generated energy changing AC-DC form three times. This is not efficient at all and I think it will negatively affect the operation of inverter devices. Instead, it is certain that a hybrid inverter that can use the alternating current produced by the alternator directly by eliminating other form converter devices will be much more efficient.

Production, packaging, transportation and assembly of each device separately creates extra costs. I'm sure Victron can produce such a device.

[T1 Terry]

Originally Posted by SOLAR SUPPORT

It is a reality that the costs of hybrid inverter devices available in the market are quite low. Before underestimating Chinese technology, it is necessary to test the working safety and capacity of these inexpensive devices. Of course, it is important to be aware of the destructive effect of the marine environment on all kinds of devices containing metal.

Instead of using cables and plug connectors to assemble devices with specific functions separately and to connect them with each other, combining them on a main board and producing them in a single box to work integrated with each other means reducing the disruptive effect of the marine environment.

The idea of ​​using an inverter for direct use of the existing alternators on board results in the generated energy changing AC-DC form three times. This is not efficient at all and I think it will negatively affect the operation of inverter devices. Instead, it is certain that a hybrid inverter that can use the alternating current produced by the alternator directly by eliminating other form converter devices will be much more efficient.

Production, packaging, transportation and assembly of each device separately creates extra costs. I'm sure Victron can produce such a device.

The problem is ripple and variation in both wave form and voltage as the alternator changes speed, as a young bloke I built a transformer to increase the 15vac coming out of the alternator to 240vac to power a soldering iron and a brush type 240vac drill. Set the hand throttle to 1500rpm and it worked a treat (there were no inverters commonly available back then) I scored a thermostically controlled soldering iron from someone who was moving up the chain of command so was no longer on the tools ..... I tried it on my special 240vac genset .... the smoke came out nearly instantly and that was the end of that ..... to control and smooth the wave pattern and stabilise the voltage would be quite a challenge and each and every alternator would require modifying to enable anything like this to be successful.

T1 Terry

[goboatingnow]

The suggestion to power an inverter from an alternator then re-invert to 12v to charge a lithium is just plain daft.

Why people go through hoops to avoid a simple alternator upgrade to use external smart regulators Is utterly beyond me.

( note that load dumping by the alternator going off line , would trigger an inductive pulse anyway. )

Also using highly integrated all in one charging systems usually designed for domestic markets is bad advice for a boat. A boat needs redundancy , bypasses etc.

[SOLAR SUPPORT]

Originally Posted by goboatingnow

The suggestion to power an inverter from an alternator then re-invert to 12v to charge a lithium is just plain daft.

Go Boating, I noticed that you made an arrogant statement directed at me in the first paragraph of your reply. I do not accept your statement and I consider it appropriate to return it to you directly.

[goboatingnow]

Originally Posted by SOLAR SUPPORT

Go Boating, I noticed that you made an arrogant statement directed at me in the first paragraph of your reply. I do not accept your statement and I consider it appropriate to return it to you directly.

As a professional EE I feel I should call as I see it. It’s daft.

Daft
“silly, foolish
1 chiefly British, informal : silly, foolish Don't do anything daft. 2 chiefly British, informal : mad, insane … he looks at me as if I were daft.”

It’s a very everyday expression where I’m from

Arrogant no , technically correct yes.

[goboatingnow]

Originally Posted by SOLAR SUPPORT

Go Boating, I noticed that you made an arrogant statement directed at me in the first paragraph of your reply. I do not accept your statement and I consider it appropriate to return it to you directly.

As a professional EE I feel I should call as I see it. It’s daft.

Daft
“silly, foolish
1 chiefly British, informal : silly, foolish Don't do anything daft. 2 chiefly British, informal : mad, insane … he looks at me as if I were daft.”

It’s a very everyday expression where I’m from

Arrogant no , technically correct yes.

I said it was a daft idea. I didn’t say you were daft.

[SOLAR SUPPORT]

Final version of my next humble LFP battery upgrade plan.

Battery isolator removed. The alternator feeds the LA motor battery and 600-800 Watt pure sine inverter. Loads on the alternator and the feeding inverter is fixed by the hybrid inverter's battery charge limit through the mains AC input.

There is no heating problem as there is no overload on the existing fabricated alternator.

The LFP battery bank is fed simultaneously with the mppt solar regulator in the hybrid inverter and the alternator-inverter feeding the hybrid inverter's AC mains input. Solar and mains battery charging can be 40A+30A, up to 70 Amps in total. 1200 Watt AC power also available at the same time from the hybrid inverter's AC output.

The voltage settings, power generation values ​​of the solar and AC charging units in the hybrid inverter can be easily adjusted with the help of the display and adjustment buttons on the hybrid inverter.

The alternative LFP upgrade solution I have described in the diagram is still in the planning stage.

I continue to use the existing chargers and alternator control circuits on my boat.

It has not yet been tested that the setup I have specified in the diagram is 100% secure. In addition, I should state that the capacity tests of the newly launched affordable hybrid inverters have not been done yet.

[goboatingnow]

Clearly the inverter will need interlocking with engine running only

Secondly the system is very inefficient as you have multiple conversion losses

Thirdly as you have a hybrid inverter , why have a second 1200 watt invertor ?

A simpler system is , dc dc from starter to lfp, conventional mppt to dc controllers and a inverter for AC outputs will be as cheap, more flexible and contains built in redundancy , ie no reliance on a single piece of equipment

[T1 Terry]

As Goboating now has said and has been said a number of times, forget about the starter battery fed inverter to the ac battery charger, I've ben there and done that and the problems far outweigh any benefits.
A DC to DC charger that can handle the constant output the lithium battery will demand, good ones you can even derate in the programming menu to avoid overload/over heating issues. The DC to DC charger, well a quality one anyway, will have start battery disconnect voltage as a programmable parameter as well, so if the alternator isn't spinning fast enough, the DC to DC charger will actually switch out until the start battery reaches the voltage you programmed into it. This way you do not drag the voltage down to a point the alternator is overloaded for the speed it is spinning due to lack of fan speed and burning out.
Just one of the things that need to be considered in you inverter to charger form of DC to DC charging.
The next issue that needs to be considered, an inverter powering a 30 amp battery charger will have to produce enough output to meet the inefficiency of the battery charger, so 30 amps x 14v = 420w plus a min of 10% losses = 462w. To supply the inverter with enough battery current to supply this 462w and allowing for the min 10% loss in the inverter brings the required battery power up to 510w. The inverter will continue to put to put out that 462w and require 510w to power it, right down to 10.5v allowing for cable losses you are now drawing 50 amps from the start battery to put 30 amps into the LFP battery ..... at low alternator speeds, as mentioned before, will really put a strain on the alternators ability to cool and also drop the motor system voltage very low and risk the motor cutting out and the start battery being drained to the point it can't restart the motor ....

Just another note, I see you plan to use the PIP inverter/charger set up, or at least one of the clones, they cause major headaches in land based systems and are only sort of reliable in the 48v form, the 24v and even worse the 12v models, suffer from heat building that finally destroys the lower quality electronics used in these things.
We used the 24v and 48v models for a number of yrs, after 5 motherboard failures in 5 different inverters using the 24v units, we gave up and moved up to the Victron units and the failures have stopped completely.
It is enough of a pain to have to travel all over the countryside to replace failed inverters and wear the cost, your reputation will suffer badly if they fail out at sea ......

T1 Terry

[SOLAR SUPPORT]

I have reviewed portable inverter generators. The system is the same until the alternator output on our boats. In these generators, pure sine inverter (PSI) is used as in the plan.

I will add a simple mechanism that works with the ignition switch warning for the automatic opening and closing of the PSI connected to the alternator.

Choosing the right inverter is important. It is reasonable to choose an PSI that has 70-100% power of the alternator tag rating. I think the PSI can operate continuously with a controlled load not exceeding 60% of its capacity. The PSI must be mounted outside of the engine room.

Since the working loads of the alternator-PSI couple are limited by the AC battery charging capacity of the HI, there would be no heating problem. Their current load levels can be easily adjusted in the HI menu already. It is possible to make adjustments in the HI menu to cut the charging voltages at the desired level lower than the drop-in LFP battery's BMS HVCutoff voltage level.

I've seen HIs improve a lot lately. They allow you to control the settings of multiple charging sources and change them as you wish. I think there is a central processor that controls everything.

It is perfectly normal for the alternator current load to be slightly higher than the AC battery charging current of the HI. The energy loss in AC cables will be much lower than in DC transmission.

I don't know which HIs work in 12-48 Volt systems that cause problems you mentioned Terry T1. I personally review HI models made specifically for RVs. Larger HIs are available for RVs with 24-volt installations. A 48 volt HI can also be used according to the same scheme, using the necessary voltage reducers.

I know the Victron brand very well. They produce highly superior modules in terms of reliability and quality. I think Victron will soon produce a device that combines and controls these modules in a single device.

[T1 Terry]

I think Victron will soon produce a device that combines and controls these modules in a single device.

I guess anything is possible, but I have my doubts and I know I wouldn't use such a set up. The PiP inverter/charger range (and their clones) have an inverter, shore power charger and MPPT solar regulator, in in the one unit. Here in Australia, it is the combined heat generated by all these devices that destroy components on the various boards, the big motherboard in the back is very susceptible as is the MPPT controller.
I understand why Victron include the shore power charger in the inverter, they are very clever devices and can actually drop the charge rate down to keep the load within the programmed shore power limits and add inverter power to the shore power to cover high loads that would exceed the shore power preset, then return to being a battery charger when the load drops down again.
They have systems that can combine all the charging and load equipment into a single management device, the the user can view and adjust as required, so I don't see a reason why they would put it all in one case .....

T1 Terry