BMS Sizing, BMS Amps

Sanwizard

Solar Addict
Yeah, that makes sense. That was one of the videos I haven't yet seen 😁



I am still in the dreaming phase. But I like the Victrons.
For those that have a 200a BMS, mine is a Heltec 200a, which comes with 2x 7awg wires on each input. I cant use larger wires, as they come out of a black box with holes just large enough for the 2 x 7awg. Would best practice be to combine those wires into a single connector, or use a smaller connnector for each wire?
 

smoothJoey

Everything works if you let it
For those that have a 200a BMS, mine is a Heltec 200a, which comes with 2x 7awg wires on each input. I cant use larger wires, as they come out of a black box with holes just large enough for the 2 x 7awg. Would best practice be to combine those wires into a single connector, or use a smaller connnector for each wire?
7 awg is an odd size.
Where did you get that wire?
I think you would have trouble getting compression lugs for 7 awg.
One 4 awg lug should fit though.
I wouldn't normally suggest it except for the oddness of 7 awg.
 

Fatty

New Member
Last edited:

Fatty

New Member
The Crydom form factor is probably more convenient.
I'm not really a fan of Daly.

Yeah, I think I would actually end up going with an inexpensive (but good quality) buck converter to drive the $20 Crydom instead of paying $250+ on the other Crydom SSRs.
 

smoothJoey

Everything works if you let it
Yeah, I think I would actually end up going with an inexpensive (but good quality) buck converter to drive the $20 Crydom instead of paying $250+ on the other Crydom SSRs.
Oops forgot to look at the price.
 

ePowerBank

Solar Enthusiast
Hello @sonny93, your thread here starts similar to where I'm currently at, first-timer trying to setup some type of BMS between batteries (48v 16s) and inverter (48v 4.4kw). And, apparently better (more efficient) setups use SSR or Relay to switch instead of high amp BMS as discussed above.

I was following your thread wondered what was your conclusion?

I'm interested in seeing a set up like referenced in our forum BMS resource sheet.

1619900598028.png
 

sonny93

Solar Enthusiast
Hello @sonny93, your thread here starts similar to where I'm currently at, first-timer trying to setup some type of BMS between batteries (48v 16s) and inverter (48v 4.4kw). And, apparently better (more efficient) setups use SSR or Relay to switch instead of high amp BMS as discussed above.

I was following your thread wondered what was your conclusion?

I'm interested in seeing a set up like referenced in our forum BMS resource sheet.

I couldnt possibly answer this question as I still did not feel confident in the answers provided in this thread. Off the top off my head, amps of BMS indicates max draw at any one time, but it had to be even less than that according to one of the posters. Im confused ><
I wish there was one big BMS guide for dummies that makes all this clear. I swear a wikipedia could be dedicated to them alone. For all the work Will does there isnt a lot of videos he has on them. Im not an electrical engineer, just a musician trying to put some solar together for his van and busking rig (the latter now working).
First time hearing about SSRs.
 

ePowerBank

Solar Enthusiast
I couldnt possibly answer this question as I still did not feel confident in the answers provided in this thread. Off the top off my head, amps of BMS indicates max draw at any one time, but it had to be even less than that according to one of the posters. Im confused ><
I wish there was one big BMS guide for dummies that makes all this clear. I swear a wikipedia could be dedicated to them alone. For all the work Will does there isnt a lot of videos he has on them. Im not an electrical engineer, just a musician trying to put some solar together for his van and busking rig (the latter now working).
First time hearing about SSRs.
Looks like you're on the same road as me - don't give up.
Not sure if anyone has shared below link with you yet - where above SSR illustration comes from (I believe in forum "Resource" section).
I'm still absorbing it myself trying to discover my version of a silver bullet.

I agree this would be great topic for @Will Prowse to take on, the whole area of BMS products seems to have plenty of room to grow I sense.
Daly seems to be flooding market, but not an ultimate solution according to the experienced.

Good luck !
 
Top