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diy solar

Rec ans sma finally play together

Pyrofx

Flux capacitor builder
Joined
Jul 27, 2020
Messages
570
Location
Oatman Az
So last year I bit the bullet and purchased a 6 unit slave and master from rec.
They are great hardware guys , but software and manuals suck.
The relays work as expected. But.... you must use some kind of precharge system. I tried one on the second cold start.

Now is the delay module overpriced ? I dont think so. It's nice to just turn on the system and off we go.

My biggest problem was if there was an error in o e of the packs. Over/under voltage , temperature, balance......

It would fault out , then shut down the sunny islands. You had to reboot EVERTHING when the problem was corrected.

Then there was the pack assingments. They were all numbers as 1. You scroll through them for the cell group you want. Ex . There are 6 number 16 cells.

After 3 weeks of back and forth with Tine at Rec , everthing is flawless. If one battery pack is cut out , the rest keep chugging along. Sunny island stays working. If the bad pack corrects itself ,it comes back on line.

The original programming meant if anything goes wrong when your gone, your screwed. Now We can sleep well at night even away from the site.
 
Great job working with REC to get the system working as it should - you no doubt made their BMS better.
 
If anyone wants an older rec bms with display I have one sitting around used it with my signle pack / sma setup.
 
I'm about to get my 6048 SMA's talking to REC BMS. Quick question for anyone with experience.... I've got it all wired to my Nissan Leaf pack and bought the software/usb cable for programming. Managed to communicate with it and fix all settings.
However, after maybe 4-5 minutes the BMW gets quite hot over 60degC. Likely this is balancing current. My highest cell is 3.999 and lowest was 3.993 , but I have a 14S7P configuration (48vdc and ~378Ah capacity). The BMS keeps going into alarm mode flashing error 5 for bmw over temperature. I have seen a video somewhere of a guy pulling the heat sink cover off and leaving a fan blowing on the balance resistors. Seems silly.
Should I keep turning it ON, then OFF when hot - until cells balance without frying the BMS? Or throw a fan on it?

Once balanced I'll attempt to hookup the SI's hopefully RS485 to RJ45 cable will communicate properly with SI's.

As an aside the REC is by no means plug-n-play easy. More of a PIA. The price point is also way up there and then the software/usb cable costs extra on a $1000cdn piece. Really? Man I've seen Arduino's for $50 that include LAN, usb, etc connectors. REC almost feels like old tech. Anyway....

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Update: about 8hrs later I have a low speed fan blowing on the bms to cool it. It balances for a few mins then overheats and turns off balancing, once 5-10deg cooler starts balancing again. At least it protects itself. Cells are around 378ah in the 7P configuration. Highest cells 3.999v, lowest 3.990 , it's taking some time to balance. It's at about 3.995 now.
 
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I'm about to get my 6048 SMA's talking to REC BMS. Quick question for anyone with experience.... I've got it all wired to my Nissan Leaf pack and bought the software/usb cable for programming. Managed to communicate with it and fix all settings.
However, after maybe 4-5 minutes the BMW gets quite hot over 60degC. Likely this is balancing current. My highest cell is 3.999 and lowest was 3.993 , but I have a 14S7P configuration (48vdc and ~378Ah capacity). The BMS keeps going into alarm mode flashing error 5 for bmw over temperature. I have seen a video somewhere of a guy pulling the heat sink cover off and leaving a fan blowing on the balance resistors. Seems silly.
Should I keep turning it ON, then OFF when hot - until cells balance without frying the BMS? Or throw a fan on it?

Once balanced I'll attempt to hookup the SI's hopefully RS485 to RJ45 cable will communicate properly with SI's.

As an aside the REC is by no means plug-n-play easy. More of a PIA. The price point is also way up there and then the software/usb cable costs extra on a $1000cdn piece. Really? Man I've seen Arduino's for $50 that include LAN, usb, etc connectors. REC almost feels like old tech. Anyway....

----------------------
Update: about 8hrs later I have a low speed fan blowing on the bms to cool it. It balances for a few mins then overheats and turns off balancing, once 5-10deg cooler starts balancing again. At least it protects itself. Cells are around 378ah in the 7P configuration. Highest cells 3.999v, lowest 3.990 , it's taking some time to balance. It's at about 3.995 now.
Did it ever balance out? Mine never has yet.
 
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