Where to purchase a Daly BMS 200A or 250A?

[RobOfYork]

I have a 4 cell LiFePo4 battery and want to purchase a Daly BMS. Either a 200A or 250A.

I see they actually have several different models of each size.

Any recommendations on what one to buy and from where?

Any links will be greatly appreciated.

[john61ct]

I didn't think they got that big.

But amps rating only matters if you are flowing the power through the circuitry.

Even a 10A BMS can just be used for the V sense functions, triggering external relays for controlling cutoffs.

You'll find proper relays robust enough to handle those power levels reliably over many lifetime cycles to unavoidably be large rare and expensive.

Saving money by going for cheap-Chinese SS versions will IMO not be a good idea.

[Rivetboy]

[QUOTE=john61ct

You'll find proper relays robust enough to handle those power levels reliably over many lifetime cycles to unavoidably be large rare and expensive.

[/QUOTE]

A Cole Hersee continuos duty solenoid rated for 200 amps with a 12vdc coil is less than $50. That seems reasonable to me. YMMV

[kazetsukai]

Make sure whatever model you pick is for LFP/LiFePo4, assuming that is your chemistry. I've seen these BMSes on ebay and Amazon, and they have both "smart" and non-"smart" versions. People seem to like the non-smart ones better.

[Rucker]

When I built my LiFePo battery I went with Daly because it seemed to be the best BMS from all accounts. At least in the high discharge space (>200A).

I've been using it for just a few months now, and hardly stressing it. Yesterday it alarmed, saying one cell voltage was very low, another very high. I did panic for a few minutes, wondering what the hell went wrong, but putting the multimeter on the battery cells everything was just fine.

Even the leads from the cells to the Daly showed the correct voltage; it appears the Daly has an internal fault. And yes, I reset it, rebooted it, disconnected it, sprayed holy water on it etc., same result--the two inner cells showed low and high.

I just bought an Overkill clone to see how it worked. I was kind of unhappy with the app that came with the Daly-not very helpful, and the Overkill app looks pretty darn good, at least on youtube.

The device also works as advertised, at least per the Off Grid Garage guy.

Anyone else have experience with the Daly failing, or not doing its job?

I'm not giving up on it yet, maybe I just have a bad unit.

[kazetsukai]

Originally Posted by Rucker

Anyone else have experience with the Daly failing, or not doing its job?

I'm not giving up on it yet, maybe I just have a bad unit.

Mine. Bluetooth failed, so no settings, no app. I haven't been able to code up RS485 comm logic to work around this yet.


Weeks ago the BMS disconnected the batteries on me in the middle of the night. I measured cells, all even... think it might have been low temp, but I cannot configure the unit nor can I see what the error was.


I ordered another 250A smart.. just fed up with the problems of this unit. Could you link me the unit you bought? Nice to have options.

[turf]

Originally Posted by Rucker

Anyone else have experience with the Daly failing, or not doing its job?

I'm not giving up on it yet, maybe I just have a bad unit.

on my diy lifepo battery i got the overkill BMS and never used the battery much... maybe 1 or 2 cycles over the course of a year.... bus was parked and not in use.

my first trip out this summer the battery was fine, when i got to my destination, the BMS fouled out and locked up the battery. it was night and i coun;dnt do much without light so i went to bed. the next day i disconnected the bms and have just used the the old built in battery charger just fine.

i need to dig into to why it failed. still no clue.

[Rucker]

Originally Posted by kazetsukai

Mine. Bluetooth failed, so no settings, no app. I haven't been able to code up RS485 comm logic to work around this yet.


Weeks ago the BMS disconnected the batteries on me in the middle of the night. I measured cells, all even... think it might have been low temp, but I cannot configure the unit nor can I see what the error was.


I ordered another 250A smart.. just fed up with the problems of this unit. Could you link me the unit you bought? Nice to have options.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
Still haven't installed it, but will definitely update with a post once I've swapped it out. Hoping the app is better than the Daly.

[Rucker]

Originally Posted by turf

on my diy lifepo battery i got the overkill BMS and never used the battery much... maybe 1 or 2 cycles over the course of a year.... bus was parked and not in use.

my first trip out this summer the battery was fine, when i got to my destination, the BMS fouled out and locked up the battery. it was night and i coun;dnt do much without light so i went to bed. the next day i disconnected the bms and have just used the the old built in battery charger just fine.

i need to dig into to why it failed. still no clue.

This business of battery management is still in its infancy.

[kazetsukai]

Originally Posted by Rucker

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
Still haven't installed it, but will definitely update with a post once I've swapped it out. Hoping the app is better than the Daly.

Ah yeah... my pack is 16S (48V), not 4S (12V). As few options there are for 4S BMSes, there are even fewer for 16S.