Battery Blues : first Li Time now SOK

Cripes... do any of the China battery folks do any inbound marketing work before designing their batteries / BMS units?

Li Time 100Ah trolling motor batteries
I first started with a pair of Li Time trolling motor batteries. I saw Will's video on youtube and thought the batteries looked great. Application was to use these in parallel in my camper. Turns out that the batteries, when fully charged, and if a charging voltage is still applied, go into a sleep state to protect the batteries. This sounds great, right? Except that the protection mode also shuts off the discharge capability. Sort of puts the battery into a high impedance mode. Terminal voltage reflects this by a much lower than full charge voltage representation (~13V)

How do you wake it up? Apply a 2A load to the battery, at which time it wakes up, goes into low impedance mode and off you go. Here's the catch.... If you have two of these batteries in parallel, you can NOT guarantee that both batteries wake up in a synchronized fashion. If so, they will not work in parallel until the active battery drops in voltage level sufficient that the impedance rises, voltage drops, and the second battery begins to draw.

Given that the sleep state voltage of the battery is waaaay down in the weeds, around 13V or lower, it could be awhile before your batteries are both "on" resulting in uneven wear on the batteries. If you are using these batteries in series, you are likely good to go. Parallel? not so much.

SOK 280Ah Battery
Here's the biggest flaw. ALL SOK BATTERIES USE THE SAME BLUETOOTH PASSWORD AND YOU CAN NOT CHANGE IT. So anybody wandering by your battery has the ability to tamper with it, and put it into what is called storage mode. This shuts off your battery until you charge it (according to their documentation, you have to charge it to get it out of storage mode). If you are boondocking at night, you are out of luck for getting that battery turned back on. Hope you didn't want heat.

They also have a sleep mode. If the battery is not used for a period of time 10 min to 9999 min, you choose (or whoever has the app and is walking by your battery chooses), then your battery goes to sleep and will not accept a charge at this time. The manual says that you can wake it from this sleep mode by EITHER charging or discharging. I found that charging did not wake the battery. A light load of 1.4A did not wake the battery. I had to put my inverter on the battery to wake it up.

You will also find that the documentation that ships with the battery no longer matches the GUI for the app. Heck, they don't even care enough to update the manual on their website to match the app.

If anybody has a solution for securing the battery from tamper, let me know. Otherwise looks like I gotta figure out how to make a faraday cage for the thing. Or buy another BMS and hack in a bluetooth disable. If SOK won't let us change the password, How hard would it have been to put a hall switch and a magnet on the thing? Grrrrr......

I've never understood the fascination of worrying about BMS security.
How many enemies have you made?
Or do you believe that random people with bad intentions are walking around with multiple BMS apps, just hoping to screw with you?

timselectric said:

I've never understood the fascination of worrying about BMS security.
How many enemies have you made?
Or do you believe that random people with bad intentions are walking around with multiple BMS apps, just hoping to screw with you?

Click to expand...

Hahaha, in a way that falls into the same category as "My BMS is Spying on me and stealing my secrets" pile.
Although, a BMS Password like any other PW on ANYTHING, should have the ability to be changed, that one is an obvious.

Not sure what BMS SOK or LiTime use but they can always be swapped out, not something that would make anyone happy.

KS_Kampers said:

SOK 280Ah Battery
Here's the biggest flaw. ALL SOK BATTERIES USE THE SAME BLUETOOTH PASSWORD AND YOU CAN NOT CHANGE IT. So anybody wandering by your battery has the ability to tamper with it, and put it into what is called storage mode. This shuts off your battery until you charge it (according to their documentation, you have to charge it to get it out of storage mode). If you are boondocking at night, you are out of luck for getting that battery turned back on. Hope you didn't want heat.

They also have a sleep mode. If the battery is not used for a period of time 10 min to 9999 min, you choose (or whoever has the app and is walking by your battery chooses), then your battery goes to sleep and will not accept a charge at this time. The manual says that you can wake it from this sleep mode by EITHER charging or discharging. I found that charging did not wake the battery. A light load of 1.4A did not wake the battery. I had to put my inverter on the battery to wake it up.

You will also find that the documentation that ships with the battery no longer matches the GUI for the app. Heck, they don't even care enough to update the manual on their website to match the app.

If anybody has a solution for securing the battery from tamper, let me know. Otherwise looks like I gotta figure out how to make a faraday cage for the thing. Or buy another BMS and hack in a bluetooth disable. If SOK won't let us change the password, How hard would it have been to put a hall switch and a magnet on the thing? Grrrrr......

Click to expand...

Very strange, but I will say I did replace the BMS from the Battle Born battery to a JBD BMS and was able to revive my bb100 battery. You could replace the BMS with a JBD 200 bms perhaps, it has a bluetooth you can unplug.

sun fun kits uses these bms in there batteries but they have switch that lets you turn the bluetooth on/off, you may wan to contact them to see if you can buy the bms and switch from them so you can turn bluetooth on or off and retrofit the sok battery?

But I'm sure you would void your warranty doing so

My batteries with dumb BMSs can't be remotely tampered with, just saying.

timselectric said:

I've never understood the fascination of worrying about BMS security.
How many enemies have you made?
Or do you believe that random people with bad intentions are walking around with multiple BMS apps, just hoping to screw with you?

Click to expand...

anyone standing close enough for the BT to connect will be in range...just saying!

When wired properly both of the batteries should see a 2a draw. Youre wired improperly.

I would rather have the ability to disable the need for a password.
It's just another annoying step.
The best I could do was reduce it to a single digit.

OffGridForGood said:

anyone standing close enough for the BT to connect will be in range...just saying!

Click to expand...

Yup
My "unwanted visitors greeter", has a much greater range than a typical Bluetooth does.

OffGridForGood said:

anyone standing close enough for the BT to connect will be in range...just saying!

Click to expand...

... with the right app installed

There are some valid points about being able to have total control of the $1200 plus battery you purchased.
But I can also see the side of SOK. If everyone had a way to change all the settings it would be hard to offer a warrantee anywhere close to what they do. Someone playing around without knowing what they are doing could destroy the battery then expect SOK to replace it.
I must admit if not for places like this forum or a preprogramed BMS I would not be able to properly charge and discharge a LifeP04 battery.
My belief is that company's that offer a warrantee of 5~10 years may and can protect themselves from experimenters. Really think about it SOK lets us self service the battery, I'm sure they do not want to start replacing batteries because someone wants to play with it.
I'm 100% sure that if a person has trouble the support team at Current Connected will offer a solution. ... Just my 5 cents

KS_Kampers said:

Cripes... do any of the China battery folks do any inbound marketing work before designing their batteries / BMS units?

Li Time 100Ah trolling motor batteries
I first started with a pair of Li Time trolling motor batteries. I saw Will's video on youtube and thought the batteries looked great. Application was to use these in parallel in my camper. Turns out that the batteries, when fully charged, and if a charging voltage is still applied, go into a sleep state to protect the batteries. This sounds great, right? Except that the protection mode also shuts off the discharge capability. Sort of puts the battery into a high impedance mode. Terminal voltage reflects this by a much lower than full charge voltage representation (~13V)

How do you wake it up? Apply a 2A load to the battery, at which time it wakes up, goes into low impedance mode and off you go. Here's the catch.... If you have two of these batteries in parallel, you can NOT guarantee that both batteries wake up in a synchronized fashion. If so, they will not work in parallel until the active battery drops in voltage level sufficient that the impedance rises, voltage drops, and the second battery begins to draw.

Given that the sleep state voltage of the battery is waaaay down in the weeds, around 13V or lower, it could be awhile before your batteries are both "on" resulting in uneven wear on the batteries. If you are using these batteries in series, you are likely good to go. Parallel? not so much.

...

Click to expand...

Sleep state? Maybe the BT shuts down but your battery would not. You even mention this when you say it needs a discharge before it will awaken. If your battery is fully charged and you keep charging it the BMS upon reaching its high voltage shutoff will curtail anymore charging. Yes at that point your voltage indication will no longer be accurate. Indeed folks that have a cell read high and BMS trip will have the DC common bus read high at the SCC output voltage and often that trips the inverter.

Applying a load to it and dropping your voltage back into the BMS operating range will allow it to accept charge again.

Batteries in parallel may not be entirely equal but they do act together. There is no wake up because they are no sleep.

If my understanding of all this is wrong I would hope that someone could explain this "Sleep" state and what purpose it has.

timselectric said:

I've never understood the fascination of worrying about BMS security.
How many enemies have you made?
Or do you believe that random people with bad intentions are walking around with multiple BMS apps, just hoping to screw with you?

Click to expand...

Yup. Having worked in semiconductor security vending to the USG for 12 years at varied classified levels, I know things that I can not un-know. Are you truly that naive?

finite said:

When wired properly both of the batteries should see a 2a draw. Youre wired improperly.

Click to expand...

Nope. Look up the word ballasting.

DBarr said:

There are some valid points about being able to have total control of the $1200 plus battery you purchased.
But I can also see the side of SOK. If everyone had a way to change all the settings it would be hard to offer a warrantee anywhere close to what they do. Someone playing around without knowing what they are doing could destroy the battery then expect SOK to replace it.
I must admit if not for places like this forum or a preprogramed BMS I would not be able to properly charge and discharge a LifeP04 battery.
My belief is that company's that offer a warrantee of 5~10 years may and can protect themselves from experimenters. Really think about it SOK lets us self service the battery, I'm sure they do not want to start replacing batteries because someone wants to play with it.
I'm 100% sure that if a person has trouble the support team at Current Connected will offer a solution. ... Just my 5 cents

Click to expand...

I don't want to play with it. But I especially don't want other people to play with it. I just want to lock it down and disable blutooth.

Mattb4 said:

Sleep state? Maybe the BT shuts down but your battery would not. You even mention this when you say it needs a discharge before it will awaken. If your battery is fully charged and you keep charging it the BMS upon reaching its high voltage shutoff will curtail anymore charging. Yes at that point your voltage indication will no longer be accurate. Indeed folks that have a cell read high and BMS trip will have the DC common bus read high at the SCC output voltage and often that trips the inverter.

Applying a load to it and dropping your voltage back into the BMS operating range will allow it to accept charge again.

Batteries in parallel may not be entirely equal but they do act together. There is no wake up because they are no sleep.

If my understanding of all this is wrong I would hope that someone could explain this "Sleep" state and what purpose it has.

Click to expand...

The sleep state is to prevent overcharging. Sadly, sleep state also prevents low impedance discharging. In other words, the battery turning fully on. If you have two in parallel, and one has ever-so-slightly less impedance, that one will initially source the current to a 2A draw, and will turn full on, while the second battery (with its high impedance state and much lower terminal voltage) will be held off.

(edit : if the batteries had a means for self ballasting while in parallel, this would not be a problem. Unfortunately, that is not a simple fix).

I tested two Li Time batteries on my bench. They both worked fine when used alone. There may have been a failure mode for one of them which kept it shut off when I loaded. I quit looking after I found the problem. Li Time was generous in refunding my $$$, but I did have to pay return shipping.

KS_Kampers said:

The sleep state is to prevent overcharging. Sadly, sleep state also prevents low impedance discharging. In other words, the battery turning fully on. If you have two in parallel, and one has ever-so-slightly less impedance, that one will initially source the current to a 2A draw, and will turn full on, while the second battery (with its high impedance state and much lower terminal voltage) will be held off.

(edit : if the batteries had a means for self ballasting while in parallel, this would not be a problem. Unfortunately, that is not a simple fix).

I tested two Li Time batteries on my bench. They both worked fine when used alone. There may have been a failure mode for one of them which kept it shut off when I loaded. I quit looking after I found the problem. Li Time was generous in refunding my $$$, but I did have to pay return shipping.

Click to expand...

Sorry but your explanation does not accord with anything I have seen before. Could you point to a source of where you are getting this information from?

KS_Kampers said:

Nope. Look up the word ballasting.

Click to expand...

Nope, id put money that he has both of the load leads coming from a single battery instead of the + coming fromthe opposite side of the bank of his - .most negative most positive. Please prove me wrong, without pics from OP though nothing is 100%. He gave a simple explanation of problem he got a simple diagnosis. Dont be so condenscending.

I do not use bluetooth BMSs. I prefer to use Victron Smart solar charge controllers to monitor battery's.
The password can easily be changed if you want to another.
The last bluetooth BMS on a battery i built i used a JBD BMS which also is able to change your password.
Someone tampering with your battery is more than likely someone you know personally that you pissed off.

KS_Kampers said:

Yup. Having worked in semiconductor security vending to the USG for 12 years at varied classified levels, I know things that I can not un-know. Are you truly that naive?

Click to expand...

Lmao
We are talking about residential battery storage. Not high priority government facilities. Who do you think is going to go through the trouble of getting within Bluetooth range, and have every BMS app on their phone, just to hopefully screw with your battery?