Sterling Power LiFePO4 (Lithium) Leisure Batteries

[arthur49]

veletron - 2021-12-08 7:02 PM

 

Hi

 

A depleted lithium will pull whatever current it can get hold off. If there is decent cabling and a connection to the alternator via a standard split/charge system, then you end up with the BMS in the battery being the only thing present to limit the current.

 

Not all alternators are built the same most will be just fine feeding massive currents (assuming the fuse allows this), but you are putting huge stress on the alternator particularly at tickover and possibly also on the BMS depending on the current flowing.

 

Additionally, basic alternator charging has no means to reduce the voltage to 'float' once the lithium's are charged, in fact as the charge approaches completion and the current drops, the voltage from the alternator at the battery will increase, and once again, you are relying only on the BMS to prevent the battery becoming damaged.

 

Given the price of these batteries, I feel that spending the extra on a BMS designed to charge them optimally is a reasonable investment.

 

Karen

 

I've tried to present ideal voltages/current to the BMS and using it as the last resort/refinement

 

B2B max voltage 14.4 max current 30A. Mains charger 14.4v / 25A. Solar 120w 14.4v / 15A

[Pete7]

Weldted, I use a Victron Orion or DC>DC charger as they are sometimes called to regulate the amount of power going to the LFP. Without this, the LFP would draw full power and overheat the alternator in quick time. The B2 B also means I can set up a lithium profile to charge with. This enables me to set a limit at 13.8v and a float at 13.45v.

 

This means the LFP isn't fully charged all the way to the top of the knee, stopping just short. Now the float is set at 13.45v. If the LFP voltage is above this, no current is supplied to the battery. Only when the voltage drops below 13.45v plus the 0.05v offset does the B2B then supply power, mainly to feed the domestic loads and stop the LFP from being discharged further. The same applies to the solar MPPT, when using the van / boat set the float about 13.45 and use the solar to run domestic appliances. So I am using the Orion B2B to control the charging rather than the BMS.

 

I have just been watching John and Mandy who have a van You Tube channel https://www.youtube.com/c/JohnMandy/videos

 

A year ago they fitted Polynovel LFP batteries. Reading the updated comments, they have removed their recommendation and replaced the batteries already. I read through the comments but couldn't get to the bottom of the problem in such a short term. Sadly they won't be the last until this technology becomes bomb proof and trully drop in, which it isn't at the moment.

 

Pete

 

[weldted]

A slightly different take.

 

 

[veletron]

These keep appearing on my FB feed. 40A B2B with Lithium mode. Competitively priced Vs Sterling

 

https://uk.renogy.com/12v-40a-dc-to-dc-on-board-battery-charger

[arthur49]

veletron - 2021-12-16 12:18 AM

 

These keep appearing on my FB feed. 40A B2B with Lithium mode. Competitively priced Vs Sterling

 

https://uk.renogy.com/12v-40a-dc-to-dc-on-board-battery-charger

 

That is very cheap.

 

I can't see that it has a wake up function for a BMS shutdown? Having said that my Votronic 30A (£178) could not wake up the BMS at the weekend despite the fact it has, supposedly, that function - died when drawing 80A/40A per battery with voltage on app showing 11.8v under that load. None of settings were wrong. Set to cut out at 10.8v and Sterling don't know why, but got it going again with mains charger!

 

Sterlings 30A is £435???

[mikefitz]

arthur49 - 2021-12-16 5:36 PM

 

- died when drawing 80A/40A per battery with voltage on app showing 11.8v under that load. None of settings were wrong. Set to cut out at 10.8v and Sterling don't know why, but got it going again with mains charger!

 

Any voltage under 12v is less than 10% SOC. The cells used for the battery are not well matched ( cell imbalance is most pronounced at low voltage) and its probable that one cell went below the low volt cell protect, ( perhaps set at 2.5 volts), this would shut the BMS down.

 

The DALY BMS may need a charge current over a certain value to 'wake up' that the Votronics unit may not provide.

 

This feature of the DALY BMS may be a problem if you have a shutdown condition and are off grid. Some B2B chargers (Victron) have a power supply mode that would provide enough current.

 

The Renogy products are being heavily promoted, but reports on USA forums indicate that there may be reliability issues and poor support from Renogy.

 

Mike

 

[arthur49]

Thank you Mike. That could explain it - Sterling couldn't. It was cold, we had not driven far since previous night so batteries did not get a full charge

[arthur49]

I'm finding getting the last 10% of charge into these batteries is a challenge.

 

Using the Votronic 25A mains charger, on continuously for 3 days should have done the trick? Charging profile for LiFePO4:

 

U1=14.40 V 0.3-1 h

U2=13.80 V 24 h

U3=13.45 V Continuous

 

When I switched off charger after a couple of hours BMS was showing batteries at 13.4v (100%)

 

One day later, with no charge or load, its fallen back to 13.3v (90%) ? And 3 days later still sitting at 13.3V.

 

[veletron]

arthur49 - 2021-12-22 10:10 AM

 

I'm finding getting the last 10% of charge into these batteries is a challenge.

 

 

If they are in the van out in the cold then this is probably your answer. Also, unless they are physically isolated from the van, there will still be a small load.

 

Mine do the same, but when away, my AH counter shows that I am able to pull 180 AH from the pair so I am not too worried. The final 10% is also harder to get at because heavy loads (inverter) cause the voltage to dive, and then either the inverter cuts out or the BMS cuts the juice. They were still supplying juice after 180AH, but certainly not for running an inverter.

 

The BMS means that you don't get the gradual fade you get with LA - all of a sudden with lithium the lights just go out and the only way to get em back on again it to supply some charge!

 

Karen

[arthur49]

"..........all of a sudden with lithium the lights just go out and the only way to get em back on again it to supply some charge!"

 

Exactly what happened to us as we were having breakfast last week - I wasn't paying enough attention to discharge/charge and the batteries died!

 

Thank you Karen. Your input and that of Mike is really appreciated :-D

[arthur49]

Karen were you aware NASA Marine have a lithium version now

 

https://www.nasamarine.com/product/clipper-bm-1-lithium-lifepo4-battery-monitor/

 

But looking at instructions it looks like state of charge / sync will never be correct and can't be set as fully charged voltage will never reach 14.4v?

[veletron]

Hi. Interesting, but I don't think i'll upgrade. I have only ever used the NASA to count AH used, and current one will do that perfectly with lithium. When it gets to 150AH used, I know I need to think about finding some sunshine or moving on!

 

Karen

[Pete7]

Interesting, but is only a 100A shunt so limited. We draw 75A with the kettle at night time so no solar to help and can draw 95A running the Sterling Induction hob. Just been looking at a Ninja Air Fryer but they draw 1550w and the Sterling inverter is only 1600w so that's on hold for the moment. We should really fit a second 120A Sterling LFP first to spread the loads a bit.

 

Oh and would love one of the new LG bi-facial solar panels which can add 10 - 26% extra by absorption to the rear of the panel. Not sure this would work on a motorhome though as you need a big air gap to get the reflected light to the back of the panel. Fun and games, to think we started with 45w of solar a decade ago just to keep the batteries topped up when away from the boat.

 

Merry Christmas folks (lol)

[arthur49]

State of Charge (SOC)

 

Just thought I'd post re SOC of my two Sterling Power LiFePO4 batteries.

 

Van in drive for 10 days now. I "store" van with batteries roughly 50% charged. We know BMS measurement of SOC is very rough but with both batteries sitting at 13.1v according to BMS the SOC's are showing as 66% and 85%

 

I reckon 13.1v is 40-50% so SOC on both batteries is miles out. 8-)

[veletron]

Yes, the SOC is nonsense - I am aware that some DALY BMS have SOC issues. I don't know whether Sterling are using fixed BMS in newer batteries. These days I just ignore it, mine say 99% when batteries are at 13.1-13.2V

 

I have now gotten to the point where I quit worrying about what the BMS says - I have an AH counter, this is a far better way of gauging what's left - I have still been able to boil a kettle via my inverter after having used 75% of the capacity (eg 150AH drawn), and I have taken them as low as 20AH remaining across the pair and they were still going. Basically unless I really try, I wont run em down!

 

Karen

[silverback]

arthur49 - 2022-02-16 11:54 AM

 

State of Charge (SOC)

 

Just thought I'd post re SOC of my two Sterling Power LiFePO4 batteries.

 

Van in drive for 10 days now. I "store" van with batteries roughly 50% charged. We know BMS measurement of SOC is very rough but with both batteries sitting at 13.1v according to BMS the SOC's are showing as 66% and 85%

 

I reckon 13.1v is 40-50% so SOC on both batteries is miles out. 8-)

 

 

 

 

for what it's worth arthur49 the soc is like that because your batteries haven't paired up yet it will take at least 50 cycles B-)

Jonathan

 

[arthur49]

silverback - 2022-02-16 7:30 PM

 

for what it's worth arthur49 the soc is like that because your batteries haven't paired up yet it will take at least 50 cycles B-)

Jonathan

 

Thank you. I tend to use voltage as an indicator of SOC. When it drops to lower than 13.1v we take care :-D

[silverback]

I have a chart for lithium hope it helps its attached

Jonathan

[arthur49]

Yes, thats the one I use from here :-D

 

https://diysolarforum.com/threads/lifepo4-voltage-chart.3156/

 

[arthur49]

veletron - 2022-02-16 1:08 PM

 

............. I have an AH counter, this is a far better way of gauging what's left

 

Karen

 

Yes, I got caught out once when BMS shut batteries down and I decided SOC on BMS is so inaccurate its unhelpful so I've followed your solution and will count Ah !

 

I now have a Victron Smart Shunt 500A (though I never draw more than 85A). From 12v Planet which with loyalty points cost me only £103, and dead easy to install and configure. "Tail current" setting is default 4% (8A) but some users say 2% so it may be trial and error to find best setting.

 

Question - my MPPT solar regulator is Votronic set to lithium. 120W panel. Do you leave it connected to batteries when "storing" van for a few weeks with batteries at 50% SOC approx, or do you pull the fuse?

[veletron]

My van is never 'stored', its always in use at least weekends so I cant answer that. I also have a camera, router and other gubbins in there that are on 24/7 so the solar panel runs that.

[Grantkay]

Hi all and Karen. Liked this thread so thought i would join in.

Van NUVenture quatro now at just under 250,000 miles.

Sterling power:

60amp bat 2 bat

32 amp ac cross over

Pro charge Ultra 30 amp

Pro pure sine 1600w inverter

solar charger 30amp MPPT

100 amp lithium bats X2

 

120amp alternator

280 watts solar

ammeter and shunt

 

I have had most of this system for over twenty years now but slowly changed to more modern up to date Sterling Power products recently finished off with the two lithium batteries which replaced 3 x 115 amp monster lead acid batteries and now my van sits higher!

 

Lithium batts are a big cost but we wild camp summer and winter while walking,cycling and sea kayaking so they never lasted long. Ive only used them on a day trip and the coffee machine plus the induction hob didnt seam to make much of a dent in the power. I use 50mm2 cable from the alternator to the lithium at the back of the van and between the batts all other wires are over sized but not as much.

 

In the van we run induction hob, kettle, toaster, coffee machine, small oven, hair drier and laptops etc as well as usb charging of phones, gps, VHF and drones etc

 

When the sun shines strong in the summer or in Europe we heat the water from the sun as well. (truma 10 ltr ).

[Joe beer]

Hi. I have 2 of these batteries on an install. One bought 6 months  ago and one reciently. 

Been having a few issues with the older one. It seems to have a Ballance problem .  One cell seems to go over voltage and disconnects the charge relay very easily when charging normally (victron charge controller is set to 14.2v and it disconnects well below this when cell 2 spikes up to 3.75v ). The cell spikes so quickly that I don't think the Ballancer ever kicks in properly so this problem may get worse and certainly won't go away. 

Power reciently switched off due to low voltage. (Low voltage disconnect on victron battery protect set to 12.0v ) but looking at the victron  bmv712 data it disconnected at only 94ah discharge. Well short of the 108ah I should have got at this LVD setting (90% of 120ah capacity)  It seems like the battery is not getting it's full charge due to the high cell voltage disconnect problem. 

I have now added an additional identical 120 sterling battery in parallel to increase the capacity and hopefully avoid more LVD issues on dull days. 

I looked at the Daly BMS app data while installing it and noticed that some of the settings were different on the 2 batteries. Settings were different on both the "active Ballance " screen and "protection parameters" screen"

Can someone with these batteries please post screen shots of the "active Ballance" and "protection parameters" screens on smart BMS ap and also include if your batteries are performing well with these settings. 

Have read in a few places now that there are quality control issues with initial Ballance and with Daly settings but have not found what the settings should be . 

Cant work out how to post my screenshots here. 

 

[arthur49]

On 11/23/2022 at 3:48 PM, Joe beer said:

Hi. I have 2 of these batteries on an install. One bought 6 months  ago and one reciently. 

Been having a few issues with the older one. It seems to have a Ballance problem .  One cell seems to go over voltage and disconnects the charge relay very easily when charging normally (victron charge controller is set to 14.2v and it disconnects well below this when cell 2 spikes up to 3.75v ). The cell spikes so quickly that I don't think the Ballancer ever kicks in properly so this problem may get worse and certainly won't go away. 

Power reciently switched off due to low voltage. (Low voltage disconnect on victron battery protect set to 12.0v ) but looking at the victron  bmv712 data it disconnected at only 94ah discharge. Well short of the 108ah I should have got at this LVD setting (90% of 120ah capacity)  It seems like the battery is not getting it's full charge due to the high cell voltage disconnect problem. 

I have now added an additional identical 120 sterling battery in parallel to increase the capacity and hopefully avoid more LVD issues on dull days. 

I looked at the Daly BMS app data while installing it and noticed that some of the settings were different on the 2 batteries. Settings were different on both the "active Ballance " screen and "protection parameters" screen"

Can someone with these batteries please post screen shots of the "active Ballance" and "protection parameters" screens on smart BMS ap and also include if your batteries are performing well with these settings. 

Have read in a few places now that there are quality control issues with initial Ballance and with Daly settings but have not found what the settings should be . 

Cant work out how to post my screenshots here. 

 

I attach screenshots of settings I use based on the recommendations by Mikefitz and Veletron earlier in this thread.

You will note the Diff Volt of 0.36v on one of my 100Ah Sterling lithiums - 18 months old.  This figure does reduce but I've never witnessed it below 0.26v.  (The other battery Diff Volt is sitting at 0.003v as I write)

So I am currently in discussion with Sterling-Power who are asking lots of questions.  To me this battery is faulty and should be replaced.  

Edited November 29, 2022 by arthur49

[arthur49]

Smart BMS App for Daly BMS

My app updated automatically to v2.4.0 on 23 Dec.  I now can't connect to my batteries!  Version includes an update to BMS firmware which fortunately I did not attempt as reading reviews it basically appears to disable the BMS!

So if you have Smart BMS suggest you don't update app and certainly don't attempt firmware update until fix has been applied.  Check reviews on PlayStore