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Your cart is empty.Heltec BMS 4-6S Capacitance Active Balancer for Car Audio Lithium Batteries This Listing Includes: (1) Capacitance Active Balancer Features: - Working voltage: 1.8V-4.5V - Suitable for ternary lithium, lithium iron phosphate, lithium titanate. - The whole battery participates in the active equalization of energy transfer at the same time - 0.1V differential voltage 1A equalizing current. The differential voltage is bigger than equalizing current is bigger. The maximum allowable working current is 5.5A - Working principle, the capacitor fit transfers the charge mover, the equalization board is connected to the battery, and the equalization is started. The original new ultra-low internal resistance MOS, 2OZ copper thickness PCB - Equilibrium current 0-5.5A, the more balanced the battery, the smaller the current, with manual sleep switch, sleep current mode is less than 0.1mA, the balance voltage accuracy is within 5mv! - The quiescent current is about 12 mA. It is recommended that the battery capacity is 60-300AH. - With under-voltage sleep protection, the voltage will stop automatically when the voltage is lower than 3.0V, and the standby power consumption is less than 0.1mA
Ravanja
2025-08-11 10:58:28
I bought this to balance some LiFePo battery cells I made. The cells I used were A123 B series configured as 12 Volts in an 3x 4S24P array giving about 180Ah capacity. Which is in the right range for this device.The principle of operation is what I liked. Capacitive charge carriers are simple, efficient and reliable. They do not make actual measurements of voltage. They basically charge a capacitor over one cell and then discharge it to another. Repeat over all the cells many times using a small charge (the capacitance) means it provides a regular balancing current. Because of the way it works it does not need to know anything about the battery. All its doing is moving charge till there is next to zero volts difference between the cells. Once this is achieved the current drops to zero as the capacitors and the cells will all be at the same voltage. Net result is very good balance and low power consumption when balanced (quiescent current).This particular one stops balancing below a certain cell voltage to avoid discharge related issues.The bonus with this technique is that it does cell balancing all the time unless you switch it off. So you get continuous balance as opposed to top or bottom balancing.I've not had it on for long so long term reliability I can't comment on, but there is not much to go wrong so long as the capacitors are higher quality. This is pretty easy to do now given the proliferation of switching supplies in the market so is cheap and well understood. I doubt I will have issues long term.Gave it five stars as it does exactly what it says it does, does it well and uses a good technique to do so.
HClarkx
2025-03-03 20:56:16
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).
David S.
2025-02-04 12:36:06
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.
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