DEVMO 2PCS 4S 14.8V 30A BMS Protection PCB Cell Board Li-ion Lithium 18650 Balance

These things are crap. Used on 30 amps and metal three of them. Don’t buy it. Go up to 100 amp with heat sync for a couple buck more and you won’t ever have issues.

Few important observations1. if you plan to use this with inductive load, compensate the load with capacitors. otherwise the unit may randomly refuse to work, shutting off power.2. when the unit shuts off power, the only way to "reset" the balancer is to start charging it, ie. turning the unit off and on will not do anything.3. whatever your plan is, once you get the cells connected to the balancer, give the balancer time to do its job, eg. leave it be for a night or two, even if your cells are all charged. otherwise you will again run into random power shut-off even with regular load (that's actually good, prevents undervoltage).The HX-4S-F30A is not made to specs (search the web for details), but it seems to be doing alright once the load inductance and the cells making your pack are balanced.It is reported that the unit allows battery overcharge so be careful.Performs well with 18650 given enough time to get the initial work done.

Summary here misrepresents the product slightly - the female connector isn’t actually attached. If you can solder or have a different method or dont need the connector, this may work. I chose this partially because of the attached female connector, making this useless for me. See attached.

Price is good but the balancer isn't attached when delivered. Have some moderate soldering skills and it is alright. I haven't used it yet but it looks like similar quality to every other BMS out there aside from the soldering. I'll update when I finally decide to finish my 4S5P project.

My Board charges fully: 16.5v output from batteries. no load: 10.7Vload (12v computer fan) :drops to 1.33VBalance leads read the correct voltages from b- to b+.Any Ideas. I have tries both boards with the same issue.

The challenge for an outside field electronic system has been how to power it with a convenient power pack that can be easily hidden or disguised in the trees door bushes.The batteries we've been using are single 1860 cells but we can stock them in parallel and series combinations to get the 12 volt 14.8 volt systems that we need this BMS circuit board allows us to conceal the electronics in a watertight assembly and then extend the batteries into tubes that can actually look like branches or at least be disguised within the trees.It's the versatility of this separate BMS module that seems to work well and supports the right size battery combinations to achieve the storage capacity required for our application with unattended electronics in the field.We have yet to see how it survives a winter cycle.

I haven't been able to install this in a project yet, but the PCB has no residue and the parts are cleanly soldered. It also includes test points for every cell and output, with the appropriate connector to solder.