What is the best and most reliable 6S 18650 protection board I can get, that actually does a good job at balancing ?
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somekind of board to prevent these batteries from getting over charged ... over voltage ... balance voltage between cells ... 18650 dont like being over discharged and overcharged so somekind of protection is required for them
I have successfully used these in some Vintage Radio BT conversions:
https://vruzend.co.uk/collections/6...i-ion-lithium-battery-cell-module-new-arrival
You can also buy them on AliExpress at a better price:
https://fr.aliexpress.com/item/1005...816542391553802276eea57!12000023374889564!sea
Whether these are the best and/or most reliable, I can't answer, but they seem to work well in my application, driving Tinysine TPA3116 amps.
Thanks. I will try them. Any idea if the actually balance the load on the batteries about equally ? Or put in another way, how long have you used them successfully ? It must be used for an Aiyima 100w mono TPA3116 bluetooth amplifier board.
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I have 5 in use by customers/family members. The longest has been in regular use for over 2 years, with these batteries:
https://eu.nkon.nl/lg-inr18650mh1-3100mah-6a-reclaimed.html?___SID=U
The 100w is more like actual 35-40w. How long do you think they can play with 6 of those batteries ?
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What power supply are you using ? Do you step-up to 25.2 V ? I use these batteries https://eu.nkon.nl/sanyo-ur18650zm2-2600mah-8a.html?___SID=U
I use these, or similar:
https://www.amazon.co.uk/Charger-Mo...c4-bb0a-ddfbee05587f&pd_rd_i=B09BBGVKS4&psc=1
https://www.amazon.co.uk/Charger-Mo...c4-bb0a-ddfbee05587f&pd_rd_i=B09BBGVKS4&psc=1
Ok. Cool. I think the board actually steps up itself. Can you play music while they charge ?
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They're often advertised as BMS, but that's inaccurate because they don't have any real smarts. PCM for Protection Circuit Module is more accurate. The DW01A is a common protection chip to prevent overcharge, over-discharge, and overcurrent, but it doesn't provide balancing. That board description at vruzend says nothing about balancing, so I suspect it doesn't. If you have good quality cells and charge them equally before building the pack, they may be OK without balancing.
Modules that include balancing usually have another row of 6-pin chips and a set of large low-ohms resistors. HY2213 are a common balance chip, often marked BB3A (for the model type). If you already have modules without balancing, there are add-on balance boards; just search ebay for 6s lithium balance board. Otherwise, here's a 6S module that includes balancing:
https://www.ebay.com/itm/192307924973
The best board is probably a name-brand thing that costs too much money. I've only used a 3S generic module (HX-3S-FL25A-A or CF-3SJH25A-C) with DW01A and HY2213, and haven't put the pack through enough cycles to tell how good the balancing is. I can say that the overcurrent protection worked when a connector frayed and shorted.
Modules that include balancing usually have another row of 6-pin chips and a set of large low-ohms resistors. HY2213 are a common balance chip, often marked BB3A (for the model type). If you already have modules without balancing, there are add-on balance boards; just search ebay for 6s lithium balance board. Otherwise, here's a 6S module that includes balancing:
https://www.ebay.com/itm/192307924973
The best board is probably a name-brand thing that costs too much money. I've only used a 3S generic module (HX-3S-FL25A-A or CF-3SJH25A-C) with DW01A and HY2213, and haven't put the pack through enough cycles to tell how good the balancing is. I can say that the overcurrent protection worked when a connector frayed and shorted.
I've been using a Bluetooth BMS from AliExpress for years now and it works really well. This is on my ebike and it's based on a TI cell balancing and protection IC.
These PCM/BMS boards do nothing to manage charging, they're just a precaution against overcharging. The charger takes care of the necessary current and voltage limiting as required by the battery capacity and voltage. So, a 6S lithium ion pack would require 6x4.2V or 25.2 V, the charger should be labeled as a lithium ion charger, and have an LED that changes color when charging. A 24V power supply could be a voltage regulated "power supply" and not a charger. Or it could be intended to charge lead chemistry batteries, and deliver around 28V. When in doubt check it with a voltmeter, and/or google the model number.
Balancing... it adds very little to the cost of making up a pack, so why not include it. You can read the hows and whys at Battery University and other places. On the other hand, like I said before, there might be little need for it if the cells are well-matched. If you have a pack made up of a dog's breakfast of recycled cells, no balancer may be able to maintain them in balance if one bank is much weaker than the rest. Or it may just take a really long time, since the balance resistors can't shunt very much current. Whether or not you use a PCM with balancing, it wouldn't be a bad idea to include a "balance connector" so you can measure the voltage of each bank, or charge and balance the battery using a hobby charger that supports balancing.
By the way, while the HY2213 chips balance cells by shunting current through a resistor, there are also active balancers that use inductors to pass energy between banks. Those are better if you charge from solar and every mW-hour is precious, or with high capacity packs where the resistive balancers can't shunt enough current.
If you have a big expensive pack in an e-bike, it makes sense to invest in a real BMS (like the kind 5th element has). Hopefully it would allow you to log voltages from each bank while under load so you can tell if there are any weak cells.
Balancing... it adds very little to the cost of making up a pack, so why not include it. You can read the hows and whys at Battery University and other places. On the other hand, like I said before, there might be little need for it if the cells are well-matched. If you have a pack made up of a dog's breakfast of recycled cells, no balancer may be able to maintain them in balance if one bank is much weaker than the rest. Or it may just take a really long time, since the balance resistors can't shunt very much current. Whether or not you use a PCM with balancing, it wouldn't be a bad idea to include a "balance connector" so you can measure the voltage of each bank, or charge and balance the battery using a hobby charger that supports balancing.
By the way, while the HY2213 chips balance cells by shunting current through a resistor, there are also active balancers that use inductors to pass energy between banks. Those are better if you charge from solar and every mW-hour is precious, or with high capacity packs where the resistive balancers can't shunt enough current.
If you have a big expensive pack in an e-bike, it makes sense to invest in a real BMS (like the kind 5th element has). Hopefully it would allow you to log voltages from each bank while under load so you can tell if there are any weak cells.
I found that the best way to position my 6 18650 batteries was in 2 x 3 18650 battery holders 50 cm apart (for balance) To avoid having a lot of wires between the 2 positions, can I somehow use 2 x 3S BMS and still achieve 24V charging and output ?
Yeah you can do this and display real time pack current draw and voltage. Then you can go into greater depth and have it display the voltages of the different banks. So you can put your phone on the handle bars, monitor the cell voltages at zero current draw and then under load. It's easy to see if any of the banks are faulty. It's actually been really useful in diagnosing pack construction issues that crept up over time.
Another useful feature is you can set the cut off voltages at both ends. So if you want to limit the charge to 4V per cell you can with the app.
I expect that would work, if both halves were equally healthy. But it wouldn't need a lot of heavy wires between the two packs; the intermediate taps just handle the balance currents and voltage sensing.