Need help!! Daly BMS and MPPT Charge Controllers

Borriez

New Member
Joined
Sep 22, 2021
Messages
5
Good day all.

I am new to DIY Solar Power Forum and I do hope that I am asking this question in the correct Forum.

We have a couple of Wireless Internet Towers and we have recently changed over from using PWM Solar Chargers with Deep Cycle Batteries to MPPT Solar Charge Controllers with 24V LiFePO4-Daly BMS batteries with MPPT Solar Charge Controllers. So far, I am having major problems with the systems as the Daly BMS switches the sites off and on (power cycle) the sites at basically dusk every day and for the life of me, I cant understand why...

A Little background:
1) All of our sites has the exact same configuration in terms of Solar Panels and Internet Equipment.
2) The sites have between 1x and 3x Canadian Solar 360W Solar Panel (40-ish Open Voltage - Cant remember the exact Voltage), all connected in parallel where needed.
3) We have either 24V (8s) 100Ah LiFePO4 Batteries or 24V (8s) 202Ah LiFePO4 Batteries, depending on the backup capacity needed.
4) The sites need at a max around 2.5A of current to drive all hardware and most of the sites use around 1.5A. This usage is required 24 hours a day and may fluctuate with 0.3A at max deviation.
5) We use either Victron 100/20 MPPT Charge Controllers or EPEver 3210AN MPPT Charge controllers.

We currently have 8 sites that we have changed over to Lithium, 4 of them power cycles every day at Dusk. The BMS switches the sites off and then back on. The site then needs to establish a connections with its adjacent towers and then passes data again. The site is then off for a total time of 1 minute until it passes data again.

Why on earth does this happen?
Every 30 seconds, we take snapshots of each site's power status.
The batteries would be at around 27V, the charging load would be at around 0.9A and the equipment load at around 1.4A. The temperature around 25C.
There is no overcharge or massive discharge. The temperature is within parameters and it's at dusk, if it was during the middle of the day it would have made better sense.

Does anyone please have a solution or recommendation to my problem?
Regards
Borriez
 

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Just John

Photon Sorcerer
Joined
Aug 15, 2020
Messages
2,443
Good day all.

I am new to DIY Solar Power Forum and I do hope that I am asking this question in the correct Forum.

We have a couple of Wireless Internet Towers and we have recently changed over from using PWM Solar Chargers with Deep Cycle Batteries to MPPT Solar Charge Controllers with 24V LiFePO4-Daly BMS batteries with MPPT Solar Charge Controllers. So far, I am having major problems with the systems as the Daly BMS switches the sites off and on (power cycle) the sites at basically dusk every day and for the life of me, I cant understand why...

A Little background:
1) All of our sites has the exact same configuration in terms of Solar Panels and Internet Equipment.
2) The sites have between 1x and 3x Canadian Solar 360W Solar Panel (40-ish Open Voltage - Cant remember the exact Voltage), all connected in parallel where needed.
3) We have either 24V (8s) 100Ah LiFePO4 Batteries or 24V (8s) 202Ah LiFePO4 Batteries, depending on the backup capacity needed.
4) The sites need at a max around 2.5A of current to drive all hardware and most of the sites use around 1.5A. This usage is required 24 hours a day and may fluctuate with 0.3A at max deviation.
5) We use either Victron 100/20 MPPT Charge Controllers or EPEver 3210AN MPPT Charge controllers.

We currently have 8 sites that we have changed over to Lithium, 4 of them power cycles every day at Dusk. The BMS switches the sites off and then back on. The site then needs to establish a connections with its adjacent towers and then passes data again. The site is then off for a total time of 1 minute until it passes data again.

Why on earth does this happen?
Every 30 seconds, we take snapshots of each site's power status.
The batteries would be at around 27V, the charging load would be at around 0.9A and the equipment load at around 1.4A. The temperature around 25C.
There is no overcharge or massive discharge. The temperature is within parameters and it's at dusk, if it was during the middle of the day it would have made better sense.

Does anyone please have a solution or recommendation to my problem?
Regards
Borriez
I have no clue why, but try a JBD BMS. They seem to have far fewer problems than Daly.
 

MrX

New Member
Joined
Jan 3, 2020
Messages
18
I think I know what the issue might be…
By default the Daly smart BMS has a sleep timeout set to 10 minutes (if I remember correctly). The bms will go to sleep disabling charge/discharge. Since your current draw is so low it will work of the PV’d rather than the battery, and if the battery is full, no charge current will go into it. The BMS will go to sleep mode. At dusk the the PV Will stop delivering and the BMS will not start up until certain current is drawn from the battery.
This might be worked around by setting the sleep timeout to a higher value, I think 60 minutes is max.
 

Just John

Photon Sorcerer
Joined
Aug 15, 2020
Messages
2,443
I think I know what the issue might be…
By default the Daly smart BMS has a sleep timeout set to 10 minutes (if I remember correctly). The bms will go to sleep disabling charge/discharge. Since your current draw is so low it will work of the PV’d rather than the battery, and if the battery is full, no charge current will go into it. The BMS will go to sleep mode. At dusk the the PV Will stop delivering and the BMS will not start up until certain current is drawn from the battery.
This might be worked around by setting the sleep timeout to a higher value, I think 60 minutes is max.
This is probably correct.
The default is 60 minutes, just FYI. It can be disabled, and also set much higher than 60 minutes.
 

Whinny

Solar Addict
Joined
Dec 24, 2020
Messages
350
Just throwing this thought out there.......
How is the load wired in? Are you using the solar controller load connection to power your site or is it connected directly to the battery?
Had this issue at a remote water reservoir and pump this summer...radio was wired to the load connection on the scc
 

MrX

New Member
Joined
Jan 3, 2020
Messages
18
This is probably correct.
The default is 60 minutes, just FYI. It can be disabled, and also set much higher than 60
Do you know how to disable the sleep time? Set the parameter to zero or?
 

Just John

Photon Sorcerer
Joined
Aug 15, 2020
Messages
2,443
Do you know how to disable the sleep time? Set the parameter to zero or?

Do NOT set it to zero, that means go to sleep NOW. Good luck getting it to wake up ever again.


The search function here is very good. Honestly, the same questions get answered over and over.
 
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