Are these cheap lithiums ok to use??

[Scrimma]

Hi all.

I bought my victron smart solar 100/50 from these guys, and they sent through some paperwork on their lithium batteries that peaked my interest due to price. I'm looking at throwing 400ah of LFP on my boat to replace the 520AH AGM i have currently.

I'm quite new to the LFP tech, so i thought i'd throw some screen shots of their advertised batteries on here and get some feedback to see if anyone has used them, heard of them, has concerns about them, has positive things to say about them and so forth.

See attachments.

Cheers
Scrimma

[RaymondR]

I am dipping a toe in the Lithium pond and to that end purchased a 100 amp hour Victron branded battery and a BMS. However, about a week after taking delivery I noticed an add in an electronics magazine for an equivalent specs battery at about half the price. I'm tempted to put in a second home brewed system using the cheaper battery, the only problem being that if the cheapy lasts as long as it's more expensive cousin and they both live for six or seven years I'm going to be really pissed off at myself.

[Scrimma]

Originally Posted by RaymondR

I am dipping a toe in the Lithium pond and to that end purchased a 100 amp hour Victron branded battery and a BMS. However, about a week after taking delivery I noticed an add in an electronics magazine for an equivalent specs battery at about half the price. I'm tempted to put in a second home brewed system using the cheaper battery, the only problem being that if the cheapy lasts as long as it's more expensive cousin and they both live for six or seven years I'm going to be really pissed off at myself.

Yeah that's kind of my thinking. They claim to have the same specs virtually as the very expensive brands that were first on the scene. I'm feeling optimistic about these as they are in Aus and are more accountable somewhat...

[newhaul]

Sorry no specific info but the specs seem a bit off to me .

Raymond the life expectancy of the bank I built is estimated to be at about 15 to 20 years.
So you will have to wait a few more years to get mad :-):-):-):-)

[Scrimma]

Originally Posted by newhaul

Sorry no specific info but the specs seem a bit off to me .

Raymond the life expectancy of the bank I built is estimated to be at about 15 to 20 years.
So you will have to wait a few more years to get mad :-):-):-):-)

Hi, thanks for the comment. I'm intrigued how the specs seem off? I'm not so clever with this darn LFP things so any help is appreciated

[CatNewBee]

The battery aböve has no management system, at least not mentioned.
The rating is something odd too, charge voltage up to 15V, low voltage 10.5V?

the currents are also quite low for a LFP 100A maximum current and maximum short time current. I would expect 600A for a 200Ah battery as maximum current, (3C) and permanent current 200A (1C), charging current 50A is also quite low.

No idea, what is inside, maybe a 100A fuse? Life expectancy 2000 cycles indicate it is un-managed. managed LFP cells have 5000+ cycles. There are also no terminals for an external BMS.

I would not use it as a deep cycle battery without cell monitoring, maybe a good start battery. It is probably made of cylindric LFP cells inside. I would request more information before buying.

[Scrimma]

Originally Posted by newhaul

Sorry no specific info but the specs seem a bit off to me .

Raymond the life expectancy of the bank I built is estimated to be at about 15 to 20 years.
So you will have to wait a few more years to get mad :-):-):-):-)

Originally Posted by CatNewBee

The battery aböve has no management system, at least not mentioned.
The rating is something odd too, charge voltage up to 15V, low voltage 10.5V?

the currents are also quite low for a LFP 100A maximum current and maximum short time current. I would expect 600A for a 200Ah battery as maximum current, (3C) and permanent current 200A (1C), charging current 50A is also quite low.

No idea, what is inside, maybe a 100A fuse? Life expectancy 2000 cycles indicate it is un-managed. managed LFP cells have 5000+ cycles. There are also no terminals for an external BMS.

I would not use it as a deep cycle battery without cell monitoring, maybe a good start battery. It is probably made of cylindric LFP cells inside. I would request more information before buying.

Thanks for that info. I does say it has a built in bms in the first attachment. I'm not too concerned about the charge and discharge rates, but closer to 100A for continuous charge would be nice. Although other than my alternator, everything else I have to charge is maxed at 50A, so not really a big deal for me.

It lists it's cycles in attachment 2. 2000 cycles at 100% discharge. That seems quite typical from what I've read as LFP should never be 100% discharged. The cycles go up dramatically with less discharge like other more known brands. Unless I'm missing something there?

I'm not sure about the high and low charge voltages. Seems strange considering LFP batteries have a much narrower charging range than that dont they? 13.9v or so? Maybe they are saying what it can handle if things are not ideal at 13.9v?

[CatNewBee]

You need more information about the BMS if there is one inside.

Especially the values at what voltage it starts balancing would be interesting.

A LFP cell is best between 2.9V (empty) and 3.65V (full), you should never go above or below this values to prevent the cell from ageing and failures / run-offs.

That said, you should not discharge below 11.6V - 10.5V is way too low. They may include in this a voltage drop of high load devices. Anyway, set your external battery monitor to disconnect at 11.8V for safety of the battery.

You should stop charging at 14.5V, 14.6V is when the battery is 100% full, above this there is no reason for charging and will damage the cells. It is very interesting at what voltage the BMS starts balancing, so you allow to go over that threshold from time to time. Otherwise it is safe to stop charging at 14.2..14.3V, the battery is then 95% full and happy, set float to 13.4...13.5V on your solar controller and all your chargers to prevent slow overcharging.

Another very interesting thing I would ask is, what the BMS does when hi voltage or low voltage alarms occure, what happens at high temperature alarm and over-current. How can you reset the error state, does it auto-reset? Is there a manual reset button / procedure? Internal Fuse / current protection?

This is essential information.

[newhaul]

Originally Posted by Scrimma

Hi, thanks for the comment. I'm intrigued how the specs seem off? I'm not so clever with this darn LFP things so any help is appreciated

here is the spec sheet for my Lfp cells so multiply the numbers by 4
Hope this is helpful

[tanglewood]

Originally Posted by newhaul

here is the spec sheet for my Lfp cells so multiply the numbers by 4
Hope this is helpful

I'm confused. They say the cell capacity is 10,000mAh, so 10 Ah. Is that right, or did they drop a zero and the cell is actually 100Ah?


And they say Constant Charge is .5C, and 20A. That says the capacity is 40Ah.


Maybe I'm not reading it right? Very confused.

[tanglewood]

They say the same thing other "drop-in" batteries say, which is that you need to set up your charging sources for LFP. It's casually stated like it's no big deal, but ends up being a big part of what makes a drop-in not really a drop-in. I'd be real interested to see exactly what they call for from chargers.

[newhaul]

Originally Posted by tanglewood

I'm confused. They say the cell capacity is 10,000mAh, so 10 Ah. Is that right, or did they drop a zero and the cell is actually 100Ah?


And they say Constant Charge is .5C, and 20A. That says the capacity is 40Ah.


Maybe I'm not reading it right? Very confused.

ok these are calb cells and 10,000mAh is 100ah which is the capacity.
40ah is not mentioned.
you mis read the charging is 20 amp constant current
With a max recommended of .5C or 50 amp
Discharge current is 50 amp constant with 100 amp burst

These are the individual cells to build a custom bank with .
So it takes 4 of them in series to be a 12.5 volt nom battery.

A really important thing is never charge the Lfp battery if the battery temperature is below 0℃ it will damage the battery.

[CatNewBee]

Originally Posted by newhaul

ok these are calb cells and 10,000mAh is 100ah which is the capacity.
40ah is not mentioned.
you mis read the charging is 20 amp constant current
With a max recommended of .5C or 50 amp
Discharge current is 50 amp constant with 100 amp burst

These are the individual cells to build a custom bank with .
So it takes 4 of them in series to be a 12.5 volt nom battery.

A really important thing is never charge the Lfp battery if the battery temperature is below 0℃ it will damage the battery.

10,000mAh is not 100ah, but 10Ah, what makes sense to pulse current of 100A (10C)

There is still no information about the BMS used and the settings on what it reacts, nor on the reset in case of error.

[newhaul]

Originally Posted by CatNewBee

10,000mAh is not 100ah, but 10Ah, what makes sense to pulse current of 100A (10C)

There is still no information about the BMS used and the settings on what it reacts, nor on the reset in case of error.

very true and that information is needed to be able to formulate an opinion about these " drop ins"
I was triggered by that 15 volt charging voltage .
15 volts will kill them on the tail of the charge.
We really need more info .

[roland stockham]

"cheap" Lithium!! So it seams interesting to spend that sort of money on a cheap lithium to see if it works? to get anywhere near the lifetime cost of FLA this battery would have to last between 50 and 100yrs, are you planning to leave it to your children?
There are reasons to go lithium, particularly if you want very high discharge rates and charge rates in the 100's of amps or super light weight (ie racing) but it is, at this time, not a cost effective option for a 'normal' cruising boat so 'cheap' should not come into the equation.