LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

[transmitterdan]

Originally Posted by john61ct

Why should anyone care about country of origin?

Quality control can svck anywhere.

There are a host of reasons one might consider the country of origin important:

Respect for intellectual property rights
Respect for basic civil rights
Transparent quality standards and practices
Prevalence of fraudulent behavior

Not everyone cares about the same things but everyone cares about some things.

[Pelagic]

Originally Posted by Dockhead

There has been discussion about the warning signs of imminent Multiplus death (false "temp" and "overload" warnings) -- something common enough to have started conversations.

I was aware of a lot Multipluss failures in the beginning. Saw a lot of them here in Subic , with new Diesel Ducks from China.

On close inspection I concluded that it was because of poor wiring of the two Victron multi pluss units to manage the shore power feed. (Can't remember the details)

So I decided to bypass that feature and my shore power is either On or Off and is used only to power the "charger only" side.

[Dockhead]

Originally Posted by Pelagic

I was aware of a lot Multipluss failures in the beginning. Saw a lot of them here in Subic , with new Diesel Ducks from China.

On close inspection I concluded that it was because of poor wiring of the two Victron multi pluss units to manage the shore power feed. (Can't remember the details)

So I decided to bypass that feature and my shore power is either On or Off and is used only to power the "charger only" side.

Ah, but then you lose Power Boost -- one of the absolute best features of the Multiplus . . .



Well mine has been reliable now for what -- 5 years? Lots of heavy use. Perhaps there was a design flaw since remedied. When I sent mine back for service it was repaired no questions asked (it was a couple of months out of warranty IIRC), and they replaced the whole main board.


I want to love this gear -- although it's expensive, it works great when it works, and the UK distributor is great to deal with.


I always thought that in my next boat (or this one if I ever do a major refit) I would have TWO of them, ganged. That way if one went down, you'd still have the other.

[Pelagic]

[QUOTE=Dockhead;2699006]Ah, but then you lose Power Boost -- one of the absolute best features of the Multiplus . . .
/QUOTE]

Interesting....
.how often and when/where do you use it?

Yacht marinas are still pretty rare in Asia and shore power is also very expensive.

My thoughts were...
..You either had reliable power, or if you didn't...... Better not to use it!

With my large storage bank and large solar output it has become less of a convenience to be inside a marina (except if leaving boat when Solar is all I need)

I may be adding a 2nd Multi once we are back on board full time and using the induction stove full time.
3000W may not be enough.

If I do add a 2nd unit, I will reconsider Power Boost, if you can convince me its value does not compromise its 2 basic functions? [emoji4]

[Dockhead]

[QUOTE=Pelagic;2699371]

Originally Posted by Dockhead

Ah, but then you lose Power Boost -- one of the absolute best features of the Multiplus . . .
/QUOTE]

Interesting....
.how often and when/where do you use it?

I use it pretty often. Not as a UPS -- one of its features. At least, rarely for that.


But to limit power drawn from a small shore power connection, or a small generator.


It does "peak shaving" -- so short term large loads are accommodated by supplementing shore power with inverted power, then the power goes back in when the short term load is over.


It makes it possible to run the boat with a shore power connection which is sized not for MAXIMUM loads, but for AVERAGE loads -- a huge difference.



So if I'm using electric heat (for example), I don't need to shut it off to run the kettle.


Or if I'm on one of those puny 6 amp French or Swedish shore power connections, I can just run the boat as usual, knowing that any power I take out, will get put back in as soon as the loads are off. It's like a "line of credit" for electrical power , and interest free to boot!




The other thing about it is that it easily deals with inrush currents from large electric motors -- like air conditioning (which I don't have) or vacuum cleaners (which I do). Will keep you from popping breakers when a large motor starts up.




Lastly -- it really sets a hard limit on what you can draw from a shore power connection. The normal Victron algorithm is to cut power from the battery charger progressively as you approach the limit, but once you are using loads which, without the charger, exceed the limit -- then it's going to draw more anyway and possibly pop a breaker or blow a fuse or, God forbid, burn out something. If Power Boost is enabled, this can't happen. Sometimes getting the power back on involves more than just flipping a breaker on a pedestal -- for example, I more often berth in normal commercial harbors rather than marinas, and the electrical boxes are normally locked, so if I pop a breaker, I won't have power until the harbormaster is on duty. Sometimes they don't have normal blue 16 amp connections in commercial harbors, and I have to use a highly questionable Shuko socket, which is inside a locked electrical box. Preventing popping one of those on a rainy weekend can be a real blessing, and only Power Boost really guarantees it.




Then lastly -- depending on your generator capacity, all the same things can apply to that. Mine is 6.5kW so 29 amps, which is pretty hard for me to overload. But a smaller generator would be a different story, and you might be even more concerned to avoid overloading your generator, than you are about popping shore power breakers. You can not only prevent overloading a generator with Power Boost, you can DERATE it -- by setting the current limit to something lower than the full capacity -- a very good idea.




OK, that more clear? For my use case, and for probably very many cruiser use cases, Power Boost is tremendously useful. For yours -- you'll have to decide yourself!

[john61ct]

Maybe shutting the gate after the horse got out, but

people do still read through this thread to learn about LFP specifically.

Maybe branch more general other topics off to other threads?

Starting new ones is free. . .

[Pelagic]

Thanks for the explanation.
Something to consider if I get a 2nd Multiplus

[CatNewBee]

Originally Posted by Pelagic

Thanks for the explanation.
Something to consider if I get a 2nd Multiplus

I have the Quattro, use the assist function on shore power to run the A/C and other stuff exceeding the Amps available, also can use it to boost the 5000W Victron Quattro inverter by another 2000W from a second Mastervolt inverter.

Its very neat indeed.

[Ny-vern]

Hi Guys,

I've been researching Lithium for the past 5 months - the more you know the fewer the mistakes and the less expensive right. This is a massive thread and i'm on page 35 (still in 2012!!). I'd like to read it all before posting my questions but that would take months and i'd really like to get going on my system.

I know its cheating and a big ask as i'm sure it would have been covered somewhere in the depths of endless discussion, but i'd much appreciate any guidance from the community.

I have the advantage of starting from scratch so no pre existing systems. I have 8 x 200Ah GBS cells and as previous posts suggest will parallel them then series.

- I hope to have three charge sources, alt. solar. inverter/charger
- A lithium bank for house and a LA for start (with the ability to charge both and use one or both to run the house/start in an emergency).


I've seen the DC distribution board from Outback marine and think that would be ideal. But at around £1000 wonder if others have a similar setup they've made themselves for a fraction of the cost.

I'm pretty new to everything and recently purchased the boat after living on her for 2 years, now in the process of finishing her of. Loads to do and learn with the opportunity to do it right the first time.

Thanks!!

[CatNewBee]

Originally Posted by Ny-vern

Hi Guys,

I've been researching Lithium for the past 5 months - the more you know the fewer the mistakes and the less expensive right. This is a massive thread and i'm on page 35 (still in 2012!!). I'd like to read it all before posting my questions but that would take months and i'd really like to get going on my system.

I know its cheating and a big ask as i'm sure it would have been covered somewhere in the depths of endless discussion, but i'd much appreciate any guidance from the community.

I have the advantage of starting from scratch so no pre existing systems. I have 8 x 200Ah GBS cells and as previous posts suggest will parallel them then series.

- I hope to have three charge sources, alt. solar. inverter/charger
- A lithium bank for house and a LA for start (with the ability to charge both and use one or both to run the house/start in an emergency).


I've seen the DC distribution board from Outback marine and think that would be ideal. But at around £1000 wonder if others have a similar setup they've made themselves for a fraction of the cost.

I'm pretty new to everything and recently purchased the boat after living on her for 2 years, now in the process of finishing her of. Loads to do and learn with the opportunity to do it right the first time.

Thanks!!

This was my project during the winter / spring time:

lifeypo4-1000ah-winston-prismatic-cells-and-all-electric-galley Maybe you find it somehow useful.

Regarding DC distribution - I have used copper bars (30mm x 5mm x 1000mm), cut them with a grinder and drilled the holes for the screws, also bended angels if needed with a vice. Used the bars to create the cell bridges, connections to the shunt and the high-amp fuses. After connecting everything I used liquid rubber paint to protect and seal the connections and the bare copper and also insulate it to prevent accidental shortcuts when using tools. The main advantage of the rubber paint is, you can easy peel it off if necessary to unscrew or change something later.

I also use copper screws, washers and copper plated spring disks to connect the cable lugs of the wires.

[Ny-vern]

Great, thank you very much. I will go through it and get back to you.

Cheers!

[greg_kulosa]

A while back in this thread (Ha! - Maybe a year or two?) there were several discussions from folks that were designing their own Battery Protection Systems.

Did anything ever come from that?

My first system used a Cellog in a RV travel trailer, and it's worked great for several years.

I'm about to build a larger system for a Class-A motorhome, and I was wondering what the current recommended system is for a DIY type application.

I am NOT interested in a system with cell balancing, and NOT interested in any "drop-in" type system that arranges the cells in series before paralleling.

I'm probably aiming for 400-ish AH system, depending on what cells I can get to fit in the space available.

And yes, cost is a factor, plus it's more fun to build it myself.

Thanks.

[diugo]

In my RV I use a low-cost Arduino-like microcontroller to monitor cell voltages, handle charging, and (very rarely) trigger a shunt-trip circuit breaker to disconnect the batteries if the voltages get out of range.

[Mick C]

Our setup is 400a/h Winston based. I use the cellloggers as an alarm generator for cell level hi/Lo and pack level hi/Lo. I also have a bmv-712 for overall hi/Lo and temp. The alarms are all consolidated into a single alarm point which drives a large contractor 200amp and a piezo beeper.
Additionally I use an old PL20 as a monitor alarm that now starts and stops the generator when we are in a low voltage situation. Between all these the batteries are managed for low/hi volt and temp at cell pack and battery level.
Additionally I have a passive balancer in both packs that keepthe cells balanced within 0.01volts.

Hope this helps.
Mick
Full time in a 30foot Winnie and part time in a 38 foot Seawind!

Originally Posted by greg_kulosa

A while back in this thread (Ha! - Maybe a year or two?) there were several discussions from folks that were designing their own Battery Protection Systems.

Did anything ever come from that?

My first system used a Cellog in a RV travel trailer, and it's worked great for several years.

I'm about to build a larger system for a Class-A motorhome, and I was wondering what the current recommended system is for a DIY type application.

I am NOT interested in a system with cell balancing, and NOT interested in any "drop-in" type system that arranges the cells in series before paralleling.

I'm probably aiming for 400-ish AH system, depending on what cells I can get to fit in the space available.

And yes, cost is a factor, plus it's more fun to build it myself.

Thanks.

[greg_kulosa]

Originally Posted by Mick C

Our setup is 400a/h Winston based. I use the cellloggers as an alarm generator for cell level hi/Lo and pack level hi/Lo. I also have a bmv-712 for overall hi/Lo and temp. The alarms are all consolidated into a single alarm point which drives a large contractor 200amp and a piezo beeper.
Additionally I use an old PL20 as a monitor alarm that now starts and stops the generator when we are in a low voltage situation. Between all these the batteries are managed for low/hi volt and temp at cell pack and battery level.
Additionally I have a passive balancer in both packs that keepthe cells balanced within 0.01volts.

Hope this helps.
Mick
Full time in a 30foot Winnie and part time in a 38 foot Seawind!

Thanks - but this is what I already have in my current RV - A Junsi Cell logger controlling a contactor for High/Low pack voltage, High/Low cell voltage, etc.

I have a TM-2030 as my monitor instead of the BMV-712, but otherwise same concept.

What I was asking was if there was anything smarter available yet. I know the House Power guy stopped selling to DIY folks.

Thanks.