Heltec 4S 5S 6S 5A Capacitor Active Equalizer Balancer Lifepo4 Lithium Lipo/Titanate LTO for Battery Car Audio Group Balancer

Bought this in hopes of balancing a 6 cell in series ultracapacitor pack I made for my car audio setup. Each cell is rated for 3V max and 3000 farads. I believe that if I would charge the pack to max of 18V I would have 500 farads to use but since I am only charging it to 14.5 while my engine is running, I think it is less. Maybe I am wrong? Anyway, without the balancer, the cell connected directly to the positive cable would always be higher voltage than the rest as that is the one first in series that is connected to the alternator and load. After connecting the balancer and bridging the LTO contact points the entire pack is exactly balanced evenly on each cell. Before balancing I had the pack sitting home unused for 5 months as I didn't use the amplifier that I made it for. So due to not using the pack the voltage dropped a little to 12.57V and the cell voltages were like this: 2.101V, 2.086V, 2.098V, 2.105V, 2.086V, 2.095V. I plugged in the balance plug to the balancer and began cleaning up my work area and in about 3 minutes time the pack equalized to the following voltages: 2.094V, 2.092V, 2.094V, 2.094V, 2.092V, 2.094V. and total voltage dropped very slightly to 12.56V. I then connected the entire pack to a power supply for 5 minutes to top off the pack and charged it up to 14.5V and then disconnected it overnight. In the morning the pack voltage was stabilized to14.2V and each cell was exactly at 2.366V. This thing is amazing! I will no doubt get another balancer like this if I build more packs.

Great quality works just fine

I have 4 DIY lifepo4 batteries in parallel, about 1100 amp hours at 12 v. The system was built as an experiment, and it stays between about 40% and 70% charge most of the time. It offers several days of use with little to no sun from my solar panels. When I put the system together, I did a top balance, as is standard for solar. After a few years of use now, at about 50% charge, I would have one cell in each of 3 batteries drop rapidly to below 2.6. It turns out, after some reading, that I should have bottom balanced these, since they rarely see 100% charge. I decided to skip the disassembly phase and just get some Heltec active balancers. They have done the trick. In about a week, they have brought the cells back into balance, with less than 10mv of delta on 3 of 4 batteries, and about 23mv of delta on the final, all 272 ah cells. They were going quite high beforehand, over 250mv at times. I think the cells are fine, just balanced wrong, but time will tell. these blancers are a great addition to my system. I had to desolder the solder bridge from the LTO pads and solder it to the LFP/NMC side on all the boards. I wish they would make the pads for the "Run" switch through-hole instead of surface mount. I tried soldering some leads for a switch to the board, but I could not get a trustworthy connection on those pads, so I put the run bridge back. If I add a switch in the future, i will probably just put it in the battery negative line.

I'm using several of these. They are rated at 5 amps but that's not accurate. They might provide 5 amps of balancing if the voltage difference between cells is a volt or more, but that's not a realistic case. The typical 20-80 mv difference in cell voltages as voltage approaches the maximum charge voltage generates at most an amp of balancing. That said, the balancing current does increase with increasing voltage difference and is greater than most BMSs provide. One might suggest that the five amps rating is the peak current that occurs when the capacitors are being charged by the cell with highest voltage, but that's not a useful measure of the effectiveness of the device. The average current would equate better to the DC application these fulfill, but that capability is not provided. Since the current waveform is more-or-less sawtooth as the unit charges and discharges its capacitors, it would take an oscilloscope and high speed current transducer to actually measure the current. So I'm guessing at the one amp capability of this unit under, maybe, 80 mv cell difference. So, you don't really know what you are getting with this device, but it does seem to work quite well. I have some badly used/abused cells that won't take a balance but are usable. This device cuts the number of high-cell-voltage cut-outs by more than half in a typical re-charge. I leave the device connected 24/7 and have not found it to discharge the batteries problematically. I store at around 50% SOC where the voltage of even badly mis-matched cells is small (less than 5-10 mv) where I think the unit does very little balancing. This said, I do keep an eye on battaries in storage or I keep a solar controller on them set at 13 volts (solar controller is set for 13.1 volts but actual battery voltage is closer to 13.0 volts).

Its perfect for my spim08hp bank