Finally found a LiFePO4 BMS with Low-temp Charging Protection

[OverkillSolar]

I just enabled shipping to all countries on my BMS and modules for $20 per order.

I will be adjusting the pricing for various countries once I get an actual order.

Its actually really difficult to get the price for amazon-partnered shipping until someone places an order.

For example I ordered a module from myself on a different account, with @matthewnz address in new zealand.
The cost for DHL shipping on it came out to only $14.71 for express which is like 4 days.

A quote for the same package on DHL.com was over $80!

 

[NEWYORKHILLBILLY]

overkill solar You doing a great job on customer service. I wish i found out about you before i ordered my BMS from aliexpress. I ordered a 120 amp CLRD model witch i believe is similar .Now that i been following the tread i wish i had waited and done more research. I realy like the fact your new models has the switch wires. I just thought i post this out there so another newbe could save themselves some aggravation and order from you with a gurrenty and tech support . If down the road i ever end up needing another i will order from you. Keep up the good service.

 

[slapshot0130]

I just got my 16S 100A in the mail and I have been having some issues connecting the device to the app on my android. The BMS comes up on the app, coming up with the connect button, but every time I get a connection failed, try again. Also to note when checking the voltage between the BMS negative and the battery positive, its only showing about 2 to 3 volts on a 24v setup. Watching Wills video it looks like his was letting through full voltage when first setting up.

Any tips to solve this issue?

 

[OverkillSolar]

I just got my 16S 100A in the mail and I have been having some issues connecting the device to the app on my android. The BMS comes up on the app, coming up with the connect button, but every time I get a connection failed, try again. Also to note when checking the voltage between the BMS negative and the battery positive, its only showing about 2 to 3 volts on a 24v setup. Watching Wills video it looks like his was letting through full voltage when first setting up.

Any tips to solve this issue?

Which device, which app version, and are you using a 16 cell BMS for a 24v system?

Post a picture

 

[slapshot0130]

Which device, which app version, and are you using a 16 cell BMS for a 24v system?

Post a picture

I was trying to use the xiaoxiang app, version 3.1.1001 and yes this BMS said it could be used all the way down to a 8s setup.

 

[OverkillSolar]

I was trying to use the xiaoxiang app, version 3.1.1001 and yes this BMS said it could be used all the way down to a 8s setup.

Did you do the activation procedure in step 4, and are you sure this thing is compatible with the xiaoxiang app?

 

[slapshot0130]

Did you do the activation procedure in step 4, and are you sure this thing is compatible with the xiaoxiang app?

I have yet to stick it on a charger after giving it the "activate pulse" since I wanted to configure everything first. I'm also not 100 percent sure that it's compatible with the xiaoxiang app either. - Any other apps that you think I should try?

 

[tomoon]

Hello Everyone. Big update on my LLT Power 4S LiFEPO4 120 Amp BMS with Bluetooth (SAME as Will's but 120 Amp version)

I switched the input and output wires to silicone 8 gauge x 3 per side which is equivalent to 3 gauge effective size.

(https://www.aliexpress.com/item/4000425316662.html?spm=a2g0s.9042311.0.0.38e94c4dDlIoAU)

TEST TODAY

Set new high and low cutoffs to test for the final setup to stay off the most vertical part of the discharge/charge curve (the knees) where very little amp hours are gained at either end yet voltages are pushed low/high.

Set:

Cutoff high: 3.50V per cell
Cutoff low: 2.90V per cell

Testing the following on my new EVE 280 AH cells in a 2P4S configuration (560 AH bank) from Amy at Shenzhen Xuba Electronic Trading Co. The other bank being made is a 4P4S x 280AH. so a 1120 AH pack. All for our offshore sailboat.

1. Usable capacity test for these new high/low cutoffs at .20C (Approx 112-120 Amps): Klien 505AH, 483 AH with DROK Meter: Will use these parameters.
2. Over current test of BMS, with BMS protection in app set to 160 amps. Ran at 147 amps discharge for 10 minutes. BMS board temp was 45C (normally at 112 amps 39.5C) and 3 wires were 35C. BMS handled load with no issues. Did not want to push further. Worked Perfectly
3. Tested high current discharge cutoff, Worked Perfectly
4.Tested high and low voltage cell cutoffs, Worked Perfectly
5. Tested High Temp Cutoff, works. Put heat gun load pointed at temp sensor, 65C set and shut down system. Worked Perfectly
6. Tested low temp cutoff discharging, works (salt ice solution, -10C set in app). Worked Perfectly
7. Tested low temp cutoff charging, 0C, Worked Perfectly

Measured amps with Klien CL380 as DROK Digital DC Multimeter Hall sensor was off 5-10 amps under for most of test

Test started at 1528 BMS Temp Battery Pack Negative 3 wire 2 wire on battery

1528 147 Amps
1538 147 Amps 44.9C 24 35C -
1539 113.6 Amps
1602 113.6 Amps 39.4C 25C 36C 36C
1620 115 Amps 39.7C 26C 37C 35C
1700 117 Amps 40.8C 27.2C 39C 37C
1730 117.5Amps 41.7C 28C 40C 37C
1800 116.2Amps 41.4C 29.7C 45C 39C
1830 120.2Amps 42.8C 30.9C 45C 41C
1900 118Amps 44.3C 31.8C 51C 43C
1930 121Amps 45.5C 33.1C 51C 45C
1951 121Amps (TEST ENDED LOW VOLTAGE CUTOFF CELL 3, 2.90V)



Therefore with above cutoffs 90% of battery capacity available still with a bit more of a safety cushion


Here are some pics of the app and of my dinning room table workshop. 4 more cells to come from Amy and I will be able to make up the 1120 AH pack.


View attachment 8666View attachment 8667View attachment 8668View attachment 8669View attachment 8670View attachment 8671View attachment 8672View attachment 8673View attachment 8674View attachment 8675

@mndare , Very impressive! Thanks for the detailed testing.

May I ask what straps do you use to hold all the eight cells together? Dose it hold them tight?

 

[slapshot0130]

Did you do the activation procedure in step 4, and are you sure this thing is compatible with the xiaoxiang app?

Just got the app information from the seller...The board works like a charm! Thanks for the quick response before

 

[davehopes]

Just a quick one as I can’t find this info anywhere. On the Xiaoxiang BMS iOS app there is a configuration setting for ‘Delta to balance’, what is this for? Is it the minimum delta before the balancing will take place?

 

[OverkillSolar]

Just a quick one as I can’t find this info anywhere. On the Xiaoxiang BMS iOS app there is a configuration setting for ‘Delta to balance’, what is this for? Is it the minimum delta before the balancing will take place?

you are correct.

 

[OverkillSolar]

Just got the app information from the seller...The board works like a charm! Thanks for the quick response before

What app is it?

 

[davehopes]

you are correct.

Great, thanks for your quick response. Currently I have one cell lower than the others and I obviously need to do a top balance with a DC power supply, however I live on a boat and that’s quite a bit harder to do especially with the lockdown in place in the UK. My charge controllers are holding the pack voltage at 13.8 driving the three cells that have more charge at around 3.43 to 3.46v with the other lagging behind at 3.36. While it’s doing this the BMS is balancing with a setting of 3.39v start voltage and delta of 5mV, I know it might take a while but will it eventually bring the other cell up? The only other option I have is buying a balancer or using resistors and it would be a while until I can get hold of them. What would your advice be?

 

[KSmith]

Ordered one of your units yesterday Overkill, based on the awesome service and advice I’ve seen from you on this forum.
Looking forward to getting my pack built and hooking it up ?

 

[OverkillSolar]

Great, thanks for your quick response. Currently I have one cell lower than the others and I obviously need to do a top balance with a DC power supply, however I live on a boat and that’s quite a bit harder to do especially with the lockdown in place in the UK. My charge controllers are holding the pack voltage at 13.8 driving the three cells that have more charge at around 3.43 to 3.46v with the other lagging behind at 3.36. While it’s doing this the BMS is balancing with a setting of 3.39v start voltage and delta of 5mV, I know it might take a while but will it eventually bring the other cell up? The only other option I have is buying a balancer or using resistors and it would be a while until I can get hold of them. What would your advice be?

If you keep the upper voltage at 13.8 you wont have a problem, the balance won't hurt you.

 

[Sgt Raven]

If you keep the upper voltage at 13.8 you wont have a problem, the balance won't hurt you.

IIRC, there is a parameter for max cell voltage you can set, too. I'm pretty sure I set one for total Battery and another for max cell.

 

[baltik]

How accurate is the energy meter on this BMS? anyone with real world feedback?

 

[Sgt Raven]

How accurate is the energy meter on this BMS? anyone with real world feedback?

The amperage going in or out seems to be pretty close, if not right on.
I've checked with my clamp meter when charging. Didn't think to check it under a load.

 

[Mrdanielmh]

Has anyone had issues trying to pair to the BMS? I can see the BMS in the list but when i click it its says 'failed to get device info failed'

Update : i tried the version from here and its now fine!

Another edit :that version doesnt have temperature control!

 

[Sgt Raven]

Has anyone had issues trying to pair to the BMS? I can see the BMS in the list but when i click it its says 'failed to get device info failed'

Update : i tried the version from here and its now fine!

Another edit :that version doesnt have temperature control!

Apple or iPhone? version #?