How do you charge your LiFePo4 Batterybanks?

[Simi 60]

Originally Posted by hjohnson

I don't have to tweak anything with my system, the BMS drives everything, and does it perfectly. Doesn't matter if it's the Multiplus, my MPPTs, or my alternator.

So you didn't set a lifepo4 charge profile?

The BMS does everything onboard on ours as well up to a point
But we still set max charge cutoff points on the Victron and the MPPT so as not to rely on the BMS to do it every time.

I am under the impression relying on the BMS for switching is a good way to kill them prematurely, especially if using mosfet for switching.

[goboatingnow]

Originally Posted by Simi 60

So you didn't set a lifepo4 charge profile?



The BMS does everything onboard on ours as well up to a point

But we still set max charge cutoff points on the Victron and the MPPT so as not to rely on the BMS to do it every time.



I am under the impression relying on the BMS for switching is a good way to kill them prematurely, especially if using mosfet for switching.

A good bms should have several cutoff control points including a charge stop voltage and above that a HVC trip.

[Simi 60]

Originally Posted by goboatingnow

A good bms should have several cutoff control points including a charge stop voltage and above that a HVC trip.

Yes, and it does
But I still don't see why it has to talk to victron stuff

[CaptainRivet]

Originally Posted by andre26

Hey Everyone, I was wondering if you have any advice for me.
I am looking for a charger to charge my future LFP batterybank, which will be 560 Ah at 24v for a whopping 13.440w, without waiting days for them to be charged.
I am going to equip my boat with a Northern Lights generator 7/9kw, the current one is 7kw, I am looking for something like 150Ah charge speed, so that in more or less 3.5h I can fully charge my battery bank (either from the generator or the shore power).
And the cheapest but reliable the better
Thanks in advance!

Eve cells can do 0.5C means you can max charge them with 280A. If you exceed 140A charge your cells bank will drift apart and you need a very good balancer to correct that. ..
24V drifts more then 12V as tolerances add 8x instead of 4x and charging it hard will support drifting.
2ndvote for Victron multiplus 24V/5000W with a 120A charger. Your solar will nearly always deliver something and that adds to the charge amps of your Shorepower charger

[fxykty]

Originally Posted by Simi 60

Yes, and it does

But I still don't see why it has to talk to victron stuff

As mentioned before: so you don’t have to set a charge profile in every piece of equipment: alternator regulator(s), solar controller(s), wind generator controller(s), hydro generator controller, shore power charger, generator. And even if you’re happy to do that, Victron charge settings only say on or off; surely you want more control than that? And what about your engine alternator?

A good BMS will provide lots of configurable triggers based on voltage, temperature, state of charge, and voltage and temperature differentials that will limit or stop charging, and also limit or stop load currents. In addition, you can set multiple charge profiles so you are optimally charging and load cycling regardless of whether you’re on shore power or intermittent solar/wind/hydro charging.

[Simi 60]

Originally Posted by fxykty

As mentioned before: so you don’t have to set a charge profile in every piece of equipment: alternator regulator(s), solar controller(s), wind generator controller(s), hydro generator controller, shore power charger, generator. And even if you’re happy to do that, Victron charge settings only say on or off; surely you want more control than that? And what about your engine alternator?.

My victron charge settings allow me to set more than that
And I don't use the alt to charge the LFP, only start.
I have been 2 years without an alt, replaced it a few weeks ago.

A good BMS will provide lots of configurable triggers based on voltage, temperature, state of charge, and voltage and temperature differentials that will limit or stop charging, and also limit or stop load currents. In addition, you can set multiple charge profiles so you are optimally charging and load cycling regardless of whether you’re on shore power or intermittent solar/wind/hydro charging

Yes
And I have all that as well
But the Victron and the MPPT are set to drop off and stop charge before the BMS has to stop it due to overcharging.

We have pretty conservative settings.
Plenty of battery, no need to squeeze every drop from them or jam that last little bit of charge in.

[CalmSeasQuest]

31.2Kwh Victron LFP (split 12V/24V system)
13.5Kw Onan Genset
2X 165ah 24V high output alternators
4X 3Kwh Multiplus charger inverts (280a nominal charging @ 24V)
~1800W Sunpower solar

https://www.cruisersforum.com/forums...ll-237840.html

[hjohnson]

Originally Posted by Simi 60

So you didn't set a lifepo4 charge profile?

The BMS does everything onboard on ours as well up to a point
But we still set max charge cutoff points on the Victron and the MPPT so as not to rely on the BMS to do it every time.

I am under the impression relying on the BMS for switching is a good way to kill them prematurely, especially if using mosfet for switching.

Nothing does any switching, at least on my boat. The only time the switches have ever fired is when I’ve done it manually to take the busses cold to work on them. What the BMS is doing is dynamically configuring the voltage and current limits on my various charge sources so that they properly charge the batteries.

As the batteries approach full, they ramp down the current and voltage settings to allow the battery balancing to do its thing (if needed) then eventually if the battery is full, it will limit things to just the load put by my boat’s systems.

[CaptainRivet]

[QUOTE=Simi 60;3622714

Yes
And I have all that as well
But the Victron and the MPPT are set to drop off and stop charge before the BMS has to stop it due to overcharging.

We have pretty conservative settings.
Plenty of battery, no need to squeeze every drop from them or jam that last little bit of charge in.[/QUOTE]

Sorry but thats a wrong way to achieve this as the BMS has to have the master control over charge and load. You always loose the game of charge settings on base of total voltage

First the BMS sees the individual cells, your MPPPT and Victron MP only the total voltage so you terminate charge on total voltage that include the voltage drop from bank till MPPT but need to be on cell level at the bank.

2nd your BMS never reaches 100% charge like this so balancing and his management is screwed up because it doesn't have/get a reference point like this.

The way to do this is set a lower end of charge parameter on the BMS and let it stop the charge earlier and it will define this as 100%SOC. The BMS knows best in your whole system when to stop charging and when you are overcharging to throw the HVC as your total voltage can be ok but one cell is much lower and one is over HVC limit then BMS disconnects while yor MPPT won't . Then compare the voltage between your BMS and MPPT and MP to find out the voltage drop. Then set your MPPT and MP end of charge paramter at 0.1V+voltage drop higher then your HVC. You can try +0.05V afterwards to get closer and can use if your BMS cuts out before MPPT does. Like this the charge parameter work as last borderline of security in case BMS fails and for that total voltage is the best you got.

[fxykty]

Also, for best longevity of an LFP battery you certainly don’t want to be regularly charging to 100% more than once a month or so. And ensure that whenever you charge above 80% that you have a reasonable load applied so that the battery doesn’t rest at that level.

[MARC D]

Originally Posted by andre26

Hey Everyone, I was wondering if you have any advice for me.
I am looking for a charger to charge my future LFP batterybank, which will be 560 Ah at 24v for a whopping 13.440w, without waiting days for them to be charged.
I am going to equip my boat with a Northern Lights generator 7/9kw, the current one is 7kw, I am looking for something like 150Ah charge speed, so that in more or less 3.5h I can fully charge my battery bank (either from the generator or the shore power).
And the cheapest but reliable the better
Thanks in advance!

I use a Mastervolt COMBIMASTER 3000w/160 amp. It will deliver exactly 160 amp to my battery bank when needed.

[hjohnson]

So I can report that my setup is working marvelously. We spent a good 36 hours on the hook, using electricity like drunken sailors, and ran our bank down to about 70%.

After some final tweaking to the configuration on the Wakespeed, I was able to get it running the way I want. With a toggle switch in one position, it will run the 85A hitachi alternator on my poor little 1GM10 all the way up to 85A, which it handles surprisingly well.

Anyhow, as the battery aproached full, the REC directed that it wanted fewer and fewer amps at 14.5V, until the alternator was only producing about 10A. At that point, for fun, I flipped on the breaker for my hot water tank, and that went right back up to 80A (until I turned it off again).

After that, the REC dropped the voltage limit to 13.9V, and the alternator followed suit, pushing in some more amps, but keeping a stable 13.9 as it ramped down to just powering the house loads.

All in all, an excellent piece of kit that is working remarkably well. Between that and the Solar power (somehow I occasionally get 160W out of 120W of panels?!) it’s a great setup.

[Simi 60]

Originally Posted by CaptainRivet

Sorry but thats a wrong way to achieve this as the BMS has to have the master control over charge and load. You always loose the game of charge settings on base of total voltage

.

It being wrong is your opinion
Many would disagree.

The BMS does have control of charge and load, never said it didn't
But the Victron and mppt have control on when to stop charge at around 27.2
BMS disconnect from overcharging @ 29v is a secondary and in theory, should never happen

[fxykty]

Originally Posted by hjohnson

So I can report that my setup is working marvelously. We spent a good 36 hours on the hook, using electricity like drunken sailors, and ran our bank down to about 70%.



After some final tweaking to the configuration on the Wakespeed, I was able to get it running the way I want. With a toggle switch in one position, it will run the 85A hitachi alternator on my poor little 1GM10 all the way up to 85A, which it handles surprisingly well.



Anyhow, as the battery aproached full, the REC directed that it wanted fewer and fewer amps at 14.5V, until the alternator was only producing about 10A. At that point, for fun, I flipped on the breaker for my hot water tank, and that went right back up to 80A (until I turned it off again).



After that, the REC dropped the voltage limit to 13.9V, and the alternator followed suit, pushing in some more amps, but keeping a stable 13.9 as it ramped down to just powering the house loads.



All in all, an excellent piece of kit that is working remarkably well. Between that and the Solar power (somehow I occasionally get 160W out of 120W of panels?!) it’s a great setup.

I’m very happy that you’re happy, but you’re going to kill your LFP battery treating it like a LA battery.

Why are you still charging the battery when it is basically at 100% SOC to hold it there? LFP is not LA - it is not good (in fact, quite bad in terms of retaining capacity) to charge and hold an LFP battery anywhere above ~50%.

Once you charge your battery to 100%, TURN OFF ALL CHARGING. Let the battery discharge to below 30%, then turn on charging again.

To repeat, LFP are not LA and the LA habit of getting to and holding at 100% is anathema for LFP. LFP likes to be held at 50% and cycle through 20-80%.

https://nordkyndesign.com/charging-m...battery-banks/

BTW, 14.5V charging and 10A trailing is pretty high - 13.9V and 2.5% of C trailing amps is more appropriate as a conservative 100% SOC.

[more]

Originally Posted by andre26

Thank you guys, for the quick replies and for your consideration.
I think that given how cheap the batteries are I can invest a bit more in the charger.
I will now have a look at the ones that you mentioned.
p.s. I don't know if it was relevant to mention that I'm in Europe so I run a 220v circuit shore/generator.

p.s.(2) any advice on an external alternator regulator? that I still don't know if my alternator will melt, so better to start already looking for something, I heard great things about the Balmars but they are expensive and hard to find in EU

@jimp1234 I plan on using the EVE 280 Ah, and as BMS a Daly 8s, I heard many different opinions on this BMS but seems to be reliable enough and at least not dangerous, I was initially planning to use the BMS from overkill but are sold out and difficult to get here in Europe sadly

https://www.svb24.com/en/mastervolt-...3000w-60a.html
for BMS this is best and cheap
https://www.aliexpress.com/item/1005...6e5f34%21%21sh

this is very,very advance BMS.
for example on app. you dont want charge simply select and you can spend eletric but not charging,or oposit.

i aded eva 280 ah cell for bowthruster,but this cell is not made for boat,car,camp this is stationery battery with super week terminal post m6

my navigation light have 2 m6 bolt.

winston,calb is cell wher you must go.


also i have 16S 280 ah for house solar i make wood box for keeping cell what if somebody fart,open window, close 00 wire connected m6 bolt to battery