Trouble Charging LiTime TM Batteries

[sunshine_eggo]

Some server rack batteries actually have a buck converter and will regulate the current. Usually it drops it to 10 amps.

I've not encountered this. I've only dealt with Pylontech and Trophy interfacing directly with a GX. In those cases, they effectively regulate current, but that's outside of this context.

In the case of a buck converter, then they simply present themselves as a load to the charger, no? The charger will simply deliver whatever voltage and current the converter draws within limit. I have a hard time imagining this would cause an issue with the way most chargers operate.

These cheap 12 volt batteries only have on and off switch though.

Yeah the power supply is wise to have. Especially in these situations. And especially when people put them into series

I can't fathom living life without the tools I have for this stuff. I know lots of folks just want a basic setup and don't want to be anymore involved with maintaining a battery than they are with the 12V in their car (Install. Replace when needed. Nothing in between), let alone learn the nuances about the "drop in" LFP batteries, but the right tools and process boosts confidence and can eliminate a lot of headaches up front.

 

[sunshine_eggo]

It is nice to have an opinion but let's stick with what the experts say.

Take your own advice. Your statement:

the BMS is ramping down the charge rate amps to allow the cells to balance which confuses the charger and can cause overheating.

Is made up and completely inconsistent with everything you quoted from Rocksolar.

This:

This doesn't happen. Period. BMS do not regulate current in any way. They are an on/off switch. If a protection parameter goes out of bounds, the BMS opens the circuit and stops charge and/or discharge as appropriate.

is wholly consistent with this:

"Current Monitoring: The BMS system monitors the current flowing into and out of the battery to ensure that it is within safe limits. If the current exceeds or falls below safe limits, the BMS will activate protective measures. " -Rocksolar

"The BMS will stop the charging or discharging process if any cell in the pack starts to overcharge or overdischarge in order to protect the cell from damage. -Rocksolar

This as a generalization is a false statement:

"Cell Balancing: The BMS system ensures that each cell in the battery pack is charged and discharged evenly to prevent overcharging or over-discharging of any individual cell." -Rocksolar

It doesn't ensure it happens. It works towards it. They've merged balancing and protection into a misleading statement. The protection function ensures cells are not overcharged or over-discharged, not balancing.

The balance function seeks to keep them top balanced. With passive balancers, this current is anemic and is too weak to even be noticed in operation unless one is evaluating data across days, weeks and even months. Active balancers are also too weak to make significant differences in an active system, but their contributions are notably more effective and can be observed when system utilization is low. In other words, you'll grow a beard watching a passive balancer balance a battery. You'll maybe get 5 o'clock shadow watching an active balancer.

Many "expert" sources are marketing oriented and dumbing down information for the unwashed masses. It seems that where you are with this. There's a big difference between quoting an "expert" and doing a lot of research and then building multiple batteries. I only see you doing the former.

 

[Partimewages]

@Solarcabin Channel
Nearly everything quoted by Rocksolar is marketing. I think you are drinking the coolant. Do some electric battery research from someone other than sales organizations and you will find the true meaning.

 

[Solarcabin Channel]

@Solarcabin Channel
Nearly everything quoted by Rocksolar is marketing. I think you are drinking the coolant. Do some electric battery research from someone other than sales organizations and you will find the true meaning.

Oh good grief!

Their info is the same you will find on just about any website discussing LFP battery storage.

I don't work for any company and have been off grid using all types of batteries including LFP for many years.

Have a great day!

 

[Solarcabin Channel]

Take your own advice. Your statement:



Is made up and completely inconsistent with everything you quoted from Rocksolar.

This:



is wholly consistent with this:



This as a generalization is a false statement:



It doesn't ensure it happens. It works towards it. They've merged balancing and protection into a misleading statement. The protection function ensures cells are not overcharged or over-discharged, not balancing.

The balance function seeks to keep them top balanced. With passive balancers, this current is anemic and is too weak to even be noticed in operation unless one is evaluating data across days, weeks and even months. Active balancers are also too weak to make significant differences in an active system, but their contributions are notably more effective and can be observed when system utilization is low. In other words, you'll grow a beard watching a passive balancer balance a battery. You'll maybe get 5 o'clock shadow watching an active balancer.

Many "expert" sources are marketing oriented and dumbing down information for the unwashed masses. It seems that where you are with this. There's a big difference between quoting an "expert" and doing a lot of research and then building multiple batteries. I only see you doing the former.

Show us your system and your credentials then?

I quoted the experts. You gave an opinion.

It appears Will also had to correct you. Not all controllers work the same.

I showered this morning!

 

[Crowz]

Show us your system and your credentials then?

I quoted the experts. You gave an opinion.

It appears Will also had to correct you. Not all controllers work the same.

I showered this morning!

Actually they do if its a single board bms (which is all you have from watching your videos). Its a glorified on/off switch when it comes to what is coming into the the cells from the main battery cables. Watch a few tear downs on the batteries like what you bought and you will see how its constructed. Will's videos are a good source.

The smaller wires you will see coming off the bms handle balancing and allow for the bms to know what the cells are at voltage wise. But when it comes to charging the battery cells themselves the current flows into the bus arrangement (large wires or actual bars) to the cells. This is raw high amp charging. The smaller leads can work at balances at very low amperage amounts. It's all it can do since those small wires would melt if each cell was being managed in the way your alluding to.

So to recap the bms in your batteries are :

Allowing it to charge or not (no changes to the amps just on or off)

Allowing it to discharge (again on or off).

Balancing individual cells at low voltage and low amperage when the battery is fully charged.

That's it. No magic past that point.

 

[sunshine_eggo]

Show us your system and your credentials then?

I think we're past that part in the other thread, no?

I quoted marketing sources the experts. You gave an opinion data supported by common knowledge and well documented BMS data.

Fixed.

It appears Will also had to correct you. Not all controllers work the same.

Will pointed out an outlier case well outside of the context of this discussion and the OP's issue/equipment.

The appropriate reaction is for you to realize that you can't count on marketing data to form a strong foundation for battery knowledge, and that you might have more to learn about LFP batteries from this forum than you can teach it.

None of us are experts at everything, but being an expert at something can trick us into thinking we have competence in other areas where we actually don't.

 

[Partimewages]

Show us your system and your credentials then?

I quoted the experts. You gave an opinion.

It appears Will also had to correct you. Not all controllers work the same.

I showered this morning!

Yep, nearly all marketing. I don't buy into that

 

[Solarcabin Channel]

I think we're past that part in the other thread, no?



Fixed.



Will pointed out an outlier case well outside of the context of this discussion and the OP's issue/equipment.

The appropriate reaction is for you to realize that you can't count on marketing data to form a strong foundation for battery knowledge, and that you might have more to learn about LFP batteries from this forum than you can teach it.

None of us are experts at everything, but being an expert at something can trick us into thinking we have competence in other areas where we actually don't.

I don't see where I claimed to be an expert?

I posted the link to support what was being discussed. I was directed to do that by the moderator.

I thought we were past that to and then this popped up.

Moving on!

 

[Solarcabin Channel]

Actually they do if its a single board bms (which is all you have from watching your videos). Its a glorified on/off switch when it comes to what is coming into the the cells from the main battery cables. Watch a few tear downs on the batteries like what you bought and you will see how its constructed. Will's videos are a good source.

The smaller wires you will see coming off the bms handle balancing and allow for the bms to know what the cells are at voltage wise. But when it comes to charging the battery cells themselves the current flows into the bus arrangement (large wires or actual bars) to the cells. This is raw high amp charging. The smaller leads can work at balances at very low amperage amounts. It's all it can do since those small wires would melt if each cell was being managed in the way your alluding to.

So to recap the bms in your batteries are :

Allowing it to charge or not (no changes to the amps just on or off)

Allowing it to discharge (again on or off).

Balancing individual cells at low voltage and low amperage when the battery is fully charged.

That's it. No magic past that point.

Ok, well when you destroy a charger or batteries because you didn't listen just don't cry to me.

Have a great day!

 

[sunshine_eggo]

Ok, well when you destroy a charger or batteries because you didn't listen just don't cry to me.

Have a great day!

You have offered no information that would prevent someone from destroying a charger.

You are responding to someone with a strong fundamental understanding of how a BMS works. You should admit to yourself that you have something to learn and then use the information provided to "overwrite" your existing erroneous understanding.

 

[Solarcabin Channel]

You have offered no information that would prevent someone from destroying a charger.

You are responding to someone with a strong fundamental understanding of how a BMS works. You should admit to yourself that you have something to learn and then use the information provided to "overwrite" your existing erroneous understanding.

Hi chip!

"but to keep my wife happy with this shit"

Probably explains it.

Moving on!

 

[dvrdwn]

I would try a different charger. There's nothing special about those batteries, very basic BMS. Sounds like the charger is being silly

I purchaced a LiTime 10 amp charger and tried it but it did not work. I returned them and repurchaced 2 other LiTime 100ah batteries w/o the low temp protection on a Black Friday sale. They charged properly. What would it take to get an external low temp sensor incorperated into the instal?

 

[Camp20144]

I purchaced a LiTime 10 amp charger and tried it but it did not work. I returned them and repurchaced 2 other LiTime 100ah batteries w/o the low temp protection on a Black Friday sale. They charged properly. What would it take to get an external low temp sensor incorperated into the instal?

I may be wrong, but doesn’t the low temp sensor just keep the battery from charging below a set temperature (32 F usually)? If these are in your fishing boat, probably not connected to solar charging, can’t you regulate this by not connecting to the charger when temperatures are forecast near 32 F. I saw some low temp BMS that don’t return to charging cycle until 60 F. Don’t recall if it was litime or ionic or Dakota. 60F looks like manually controlled charging is better anyway.

 

[VeritasCupitor]

Another Newbie here with a similar LiTime experience. I bought 4 new LiTime 12V 230Ah Plus Low-Temp Protection LiFePO4's. As received charge was 13.1V I 1st tried charging with a 20A" LiFePO4 charger from Amazon and got strange results. The battery charged for 14.2 v, 15.4 amps (never got to 20A). After over 6 hours charging, and the charger shut off with a message of "FULL" , the voltage dropped to 13.0v. Next morning its 12.89v. Emailed LiTime and got this response: "Pls do not worry. After this battery is protected from overcharge, the tested battery voltage (not the real voltage) will be lower than the real voltage. To calculate the SOC , add 0.5V to 0.7V to the tested battery voltage. The attached updated user manual screenshot is for your reference. We recommend that you take a small load and discharge it for one minute, then leave it for 30 minutes before testing the voltage, at which point the voltage should return to normal (13.33V and above)". I did what they recommended and the charge did increase.

I upgraded to a Victron Energy Smart Ip22 12vdc 30a AC charger and charged the 2nd battery - starting voltage 13.17V, bulk charging with 14.6V @ 30.0A. When it got to Absorption charging the app showed 14.6V 0.0A. When it moved into "Storage" the app showed 13.25V 0.0A. After disconnecting and resting for a day the battery was at 12.9V. I put a load of one 150W lightbulb on it for 2 minutes and now it's holding at 13.35V.

What is the normal full resting charge of a 12V LiFePO4 battery?

Thanks in advance.

 

[sunshine_eggo]

Sounds like the 12.89V is an arbitrary voltage reported by the BMS after charge protection event as evidenced by the INCREASE in voltage after you apply a load.

It may also serve as a "standby" voltage when the battery is inactive.

 

[VeritasCupitor]

LiTime claims the full resting voltage is >13.33V but other charts show 13.6V as full and 13.3V as 90%. What's a "normal" full resting charge?

 

[sunshine_eggo]

LiTime claims the full resting voltage is >13.33V but other charts show 13.6V as full and 13.3V as 90%. What's a "normal" full resting charge?

13.4-13.8 typically, but that's the sum of the cells. The BMS can report anything it wants.

 

[ryankshaw]

I returned them and repurchaced 2 other LiTime 100ah batteries w/o the low temp protection ... What would it take to get an external low temp sensor incorperated into the instal?

I'm have the same and am curious to see if anyone has any answers for you. one specific thing that I have wondered is what if I bought just 1 LiTime with low temp protection and put that in series with another liTime without it? would the low temp protection on the one protect both in series?

 

[constantspeed]

Another Newbie here with a similar LiTime experience. I bought 4 new LiTime 12V 230Ah Plus Low-Temp Protection LiFePO4's. As received charge was 13.1V I 1st tried charging with a 20A" LiFePO4 charger from Amazon and got strange results. The battery charged for 14.2 v, 15.4 amps (never got to 20A). After over 6 hours charging, and the charger shut off with a message of "FULL" , the voltage dropped to 13.0v. Next morning its 12.89v. Emailed LiTime and got this response: "Pls do not worry. After this battery is protected from overcharge, the tested battery voltage (not the real voltage) will be lower than the real voltage. To calculate the SOC , add 0.5V to 0.7V to the tested battery voltage. The attached updated user manual screenshot is for your reference. We recommend that you take a small load and discharge it for one minute, then leave it for 30 minutes before testing the voltage, at which point the voltage should return to normal (13.33V and above)". I did what they recommended and the charge did increase.

I upgraded to a Victron Energy Smart Ip22 12vdc 30a AC charger and charged the 2nd battery - starting voltage 13.17V, bulk charging with 14.6V @ 30.0A. When it got to Absorption charging the app showed 14.6V 0.0A. When it moved into "Storage" the app showed 13.25V 0.0A. After disconnecting and resting for a day the battery was at 12.9V. I put a load of one 150W lightbulb on it for 2 minutes and now it's holding at 13.35V.

What is the normal full resting charge of a 12V LiFePO4 battery?

Thanks in advance.

I bought three new Li Time 230Ah Plus with LTCP and am having exactly the same experience as you describe. All of them arrive with a voltage around 13.11v. I charge with a Victron IP22 30A charger, and when it completes the cycle, the battery reads 12.89v or 12.96v ----this has been the case with all three of these batteries. I connected each to an inverter and run a space heater for a few minutes, and the voltages of each battery, after resting, does tick up to 13.33v or close to it. The outstanding question remains, however, if any of the batteries attained a full charge?
Somehow I am sure the BMS they are using is the culprit here. Is it a problem or a feature? Not sure. Will need to try a capacity test discharge, but am not really happy that I am going through all of this run-around with these batteries. I have several other smaller (100Ah) Li Time and Ampere Time batteries that I have been quite happy with, and without issues like this. The 200A BMS in these units must be programed differently.

Will does recommend this specific model---the Li Time 230Ah with LTCP, on his website---but I have yet to see a video from him specifically talk about this battery, let alone test it and tare it down. Would really be interested if he encounters the same initial experience.