Monitoring individual cell voltages

Anyone got any experience with one of these?

£87.26 17%OFF | 300A 8S 12S 24S Cell Lithium Battery Protection Board Smart Display Balance BMS Coulomb Meter lifepo4 Lipo li-ion APP Bluetooth

My build is 12s 12ah 50c max discharge - 2 x 6s lipo - dual maytech 6374s sealed with focbox unity - and wondered if this is going to be suitable? Rated higher than I need but price difference is negligible so may as well over-spec.

Any disadvantages or is this the ideal solution for charging and battery protection in my case?

Extremely grateful for any advice! :slight_smile:

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Thanks @deucesdown for the additional information. Very useful! I added some bits to the original post. Will do more updates later when I have more time.

I’ll definitely make the FW available. Note though that this won’t be an additional functionality to the DAVEga. It only has a single UART port so you can either hook it up to a VESC or to a Smart BMS, but not both. Also even if I somehow figured it out, there’s not enough flash memory for combining the two firmwares.

You could make an enclosure for dual DAVEga though. :wink: The next obvious evelution step then is the DAVEga Unity! :smiley:


It looks huge and well over powered for our needs but if that doesn’t bother you I guess it’s fine

The guys at will customize the series count and settings for you, within limits of hardware (up to 15s)

Found this external 12s bms too in case it’s useful to anyone…

£83.63 | free shipping 300A BMS 2S - 16S LiPo LiFe Battery Management System TFT LCD Display Smart Lithium lifepo4 Li-ion Chargery BMS16

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the post is great. well done @janpom

Personally your 1.3 solution looks great. If only we could hook this up to VESC and get the data through metr same as DieBieMS.

I believe the UNITY has spare serial ports accessible inside via headers, they are there for future modules like the BT module that’s included. I believe they were planning on releasing the spec for these modules.

Hooking charge only smart BMS directly to unity would be ideal :+1:

external or internal? its 3 x 4 inches in size, supports regenerative breaking. you could see that display from the deck no problem :sunglasses:

External in the sense it has its own housing, but yeah I guess could be mounted internally too…

EDIT: doesn’t have a balance function, oddly - so it’s a bust

Option #1.2 (LLT Power Smart BMS + bluetooth module) looks like the most builder & budget friendly option. Has anyone else used this BMS with success? I’m curious to know how many builders are using this product.

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In my feeble mind this one looks pretty simple?

Ah nevermind, the output is just safe/no-safe indicator. But, things learned: there’s probably an IC that does what we want, and this guy uses a MUX too. And, the boolean output is on a clock signal, so you can tell if it crashed/froze.

Clicking around on, found this video, didn’t watch yet, but the title is nice

Oh, and this (15s, cell voltages, error less than 2.2mV, SPI). And it has balancing? But the diagrams look more complicated. $19 for the chip at arrow. Looks tiny!

Oh hey this is looking interesing now. Demo board:

Aaah there’s a demo board but $150-200

Did I mention I’m lazy? :slight_smile:

The Chargery BMS16 that @Chrisjarram has linked looks pretty cool for use as an external BMS. Unfortunately, I haven’t been able to find any reviews. Does anyone have one?

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Chargery is considered quality stuff, from reading various threads at ES. but I couldn’t find much chatter about the brand!

I want one! I guess it has 6s balance plug slots on side. ? I’ll be looking n likely ordering. Seems to have more features and bigger price than needed for off board balancing

2x 8s, I guess. Was considering it but was put off at the time by the requirement to use relays for charge and discharge.

Is it just that it uses relays instead of MOSFETs internally or do you need to provide external relays?

Looks like the latter. OK, that’s indeed clunky. Better to stick with the LLT Smart BMS and make a nice case, display and beeper alarm for it.

i am tempted to buy the LLT smart bms, but why is it so much smaller than a bestech BMS. My 80A 10s bestech is almost 2,7cm high. The llt only 1,5cm.

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Not my area of expertise, but I suppose it could have to do with the fact the LLT BMS is rated only 60A and that’s only if you get the aluminium housing (as @deucesdown pointed out here), which probably dissipates a lot of heat.

I bought one of these , its WAY bigger than expected yet to setup and play with it but seems good value if you have the space

really like the amount of config


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