KS_Kampers
New Member
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......
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......