Thread Rating:
  • 1 Vote(s) - 4 Average
  • 1
  • 2
  • 3
  • 4
  • 5
Question about wiring BMS to solar charge controller
#1
pardon me but i'm new in building battery packs  Huh
So i ordered a 7S BMS i just wanted to ask if i can wire like this to my charge controller. the C-(yellow wire) and P-(blue wire) seems like they are common(-) but Manual says C- is for charging and P- is for LOAD can i do this? see my diagram. BTW the charge controller will compensate the load if there is enough energy from the sun and if the energy from sun is not enough the load will get energy from the battery.
Reply
#2
test the passage from C- to P- with the multimeter if you have complete passage it could also be the C- and P- the same are only two solder points.
Reply
#3
Most likely, yes. charging negative and load negative (and battery negative for that matter) is usually the same. And the negative ports on the charge controller are usually all commoned as well. Like Walde said, check the traces on the PCB and the continuity between C-, P- and B-. For the controller it should also be stated in the manual.
Reply
#4
Check what load you can actually put on the charge controller as they are typically only rated for a light load to be attached, as per the light you have in the diagram. The actual load should be attached to the BMS as this should open circuit the load when the battery voltage drops to the minimum set point on the unit and prevent the battery from being over discharged. Same with over charging.
DCkiwi likes this post
Reply
#5
Given that the Victron unit is much higher quality than the BMS, and that the Victron unit is doing all the main functions like charge control & load disconnect, I'd have the batteries directly connected to it & have the BMS in parallel & across the cells for balancing.
I would not want the BMS to disconnect the Victron if it decided it should for some reason.
You would probably join the C- & P- & B- terminals alll together on the BMS but follow the tracks & test continuity first.
Running off solar, DIY & electronics fan :-)
Reply
#6
Victron dont know about individual cell voltage s and thats why you have the bms in between
LEDSchlucker likes this post
The Ultimate DIY Solar and build place
YouTube / Forum system setup / My webpage  Diy Tech & Repairs

Current: 10kW Mpp Hybrid | 4kW PIP4048 | 2x PCM60x | 83kWh LiFePo4 | 10kWh 14s 18650 |  66*260W Poly
Upcoming: 14S 18650~30kWh | Automatic trip breakers, and alot more
Reply
#7
(02-03-2019, 07:17 AM)daromer Wrote: Victron don't know about individual cell voltages and that's why you have the bms in between

True. I was also thinking the Victron might not like it if it was disconnected from the battery while charging.
DCkiwi likes this post
Running off solar, DIY & electronics fan :-)
Reply
#8
(02-03-2019, 05:30 AM)Redpacket Wrote: Given that the Victron unit is much higher quality  than the BMS, and that the Victron unit is doing all the main functions like charge control & load disconnect, I'd have the batteries directly connected to it & have the BMS in parallel & across the cells for balancing.
I would not want the BMS to disconnect the Victron if it decided it should for some reason.
You would probably join the C- & P- & B- terminals alll together on the BMS but follow the tracks & test continuity first.

I just joined C- P- & B- since they have continuity, i just tried connecting the battery directly to victron and in parallel with BMS so far there is no problem and cells are balancing. thanks for the advice guys specially redpacket to the rescue again Big Grin
Reply
#9
Having the bms in parallel then you just screwed ur self Up... Because you just removed the protection the bms supplies. The balancing is just a minor part among it all.

Please leave the bms in between instead so it can do its job. IF you think it disconnect to Early you have wrong settings.

IF you bypass just to get it charging again im fine with it but monitor it Smile
The Ultimate DIY Solar and build place
YouTube / Forum system setup / My webpage  Diy Tech & Repairs

Current: 10kW Mpp Hybrid | 4kW PIP4048 | 2x PCM60x | 83kWh LiFePo4 | 10kWh 14s 18650 |  66*260W Poly
Upcoming: 14S 18650~30kWh | Automatic trip breakers, and alot more
Reply
#10
is the solar charge controller running in common negative (my guess), or common positive?

it appears this BMS is in common positive mode.  which is fine.  but ... to be aware of if you are mixing with a common neg controller..

NB do NOT EVER short B- with either P- or C-.  this will bypass all shunts which provide over current protection. shunts will show as 'shorts' on multimeters but they are NOT just commoned.  the B- is for the battery only.  ever.

the big/real load -ve SHOULD be connected to P- (blue wire), as completelycharged noted.  also, my gut feeling says the blue wire should be connected to nothing else.  as daromer says, you need the BMS protection inline. but then ...

redpacket brings up a good point about disconnecting a battery from a charge controller while charging.  that is a bad thing for sure.  im just not convinced you are going to be able to use these two things together and keep functionality from both. (refer first my two paragraphs)

FYI if the battery does not get to 4.25V / cell it is unlikely that the 'BMS' will do any balancing at all. that is, if you have the charge limit set on the controller too low ... might never get balanced by this method. 

i go by the rough rule that if battery goes out of balance, use more P.  my $0.02
--    ----    ----    ----    ----    ----    ----    ----    ----    ----    --
all systems nominal... rock on.
-----------------------------------------------------------------------
Reply


Who read this thread?
100 User(s) read this thread:
daromer (04-24-2019, 01:29 PM), Sean (04-24-2019, 11:40 AM), station240 (02-04-2019, 05:06 AM), Korishan (03-04-2019, 12:45 PM), P.Tasyo Powerwall (03-01-2019, 05:42 PM), jdeadman (03-04-2019, 02:36 PM), wim (03-03-2019, 06:47 AM), wimpie007 (02-10-2019, 07:43 AM), watts-on (04-24-2019, 03:36 PM), Dan Lim (03-31-2019, 08:06 AM), jesusangel (03-04-2019, 07:53 PM), Hanssing (03-03-2019, 07:58 AM), KtB (04-26-2019, 04:24 PM), Mazlem (03-05-2019, 05:04 PM), Geek (04-29-2019, 05:13 AM), floydR (02-02-2019, 05:01 PM), DarkRaven (03-06-2019, 10:27 AM), Grumplestiltskin (02-05-2019, 06:49 PM), DCkiwi (04-30-2019, 05:14 AM), Oz18650 (04-23-2019, 05:00 AM), Mallusone (02-05-2019, 06:03 PM), AndyMc1970 (04-10-2019, 12:15 PM), karmi27 (02-19-2019, 12:26 AM), bigblue (04-23-2019, 08:27 AM), Ste Collister (02-11-2019, 08:18 AM), Charly144 (02-13-2019, 08:46 PM), djuro (03-02-2019, 01:59 PM), gpn (03-07-2019, 05:12 PM), Headrc (04-23-2019, 02:00 PM), kanchana (06-04-2019, 01:11 PM), rodagaster (04-23-2019, 12:36 PM), happydaddy (02-16-2019, 10:03 PM), Crimp Daddy (04-24-2019, 12:04 AM), jonyjoe505 (04-23-2019, 03:36 AM), Redpacket (04-25-2019, 08:08 AM), completelycharged (02-12-2019, 09:57 PM), Oliman (05-15-2019, 08:55 AM), Peter T (03-03-2019, 08:30 AM), Cherry67 (04-24-2019, 05:39 PM), Walde (02-02-2019, 10:02 AM), Riplash (04-23-2019, 11:32 PM), bukvaahmed@gmail.com (02-10-2019, 09:27 PM), Joel McFarlane (02-28-2019, 09:31 PM), Mikethezipper (02-11-2019, 03:38 AM), CKJ (04-22-2019, 05:43 PM), chuckp (05-25-2019, 04:30 PM), emuland-metroman (04-23-2019, 04:38 AM), Beholder (02-05-2019, 11:13 AM), Bazlouran (04-23-2019, 05:25 AM), kwabdul (03-25-2019, 07:04 PM), Truth (04-06-2019, 06:03 AM), kremvax (04-21-2019, 01:35 AM), singlecell (04-10-2019, 10:19 AM), sl1me (04-22-2019, 08:05 AM), Jernau (05-19-2019, 03:21 PM), Wolf (04-25-2019, 12:11 AM), iscience (03-09-2019, 12:32 PM), Toubab (02-05-2019, 08:27 AM), Wardy (02-11-2019, 09:19 PM), ibikunle (02-12-2019, 10:21 PM), camthecam (03-11-2019, 10:12 PM), gwall#1 (02-14-2019, 03:40 AM), Generic (04-11-2019, 04:49 PM), stevelectric (03-04-2019, 03:30 PM), PaulDane (02-22-2019, 11:23 PM), ajw22 (03-04-2019, 02:29 PM), RikH (05-07-2019, 07:32 AM), -olivier- (03-04-2019, 12:35 PM), lloulou11 (03-07-2019, 11:54 PM), DomingoRP (04-22-2019, 08:44 PM), kevinjaye (03-01-2019, 03:23 AM), oloyeadeniran (02-05-2019, 07:50 AM), mart1nn (02-06-2019, 09:07 PM), LEDSchlucker (03-04-2019, 07:02 PM), Crash_3174 (04-12-2019, 01:25 AM), Powersaver (03-14-2019, 07:51 AM), kurt13r (02-21-2019, 04:03 PM), Richard (03-04-2019, 06:36 PM), Legolfeur95 (02-09-2019, 06:29 PM), Iker138 (03-10-2019, 08:39 PM), Overmind (02-08-2019, 08:40 AM), ma3006he (04-23-2019, 07:32 PM), mskip (02-10-2019, 08:55 PM), Church1182 (03-07-2019, 12:39 AM), fleming (04-10-2019, 11:29 AM), zeme (03-31-2019, 03:04 AM), rhedbatt (07-15-2019, 09:19 PM), geoca (02-20-2019, 08:23 AM), Edster (02-11-2019, 12:42 PM), valueseek (05-02-2019, 03:20 PM), mram (02-09-2019, 02:05 PM), Lion (02-25-2019, 04:24 PM), Omalik (05-16-2019, 08:36 PM), MilkMan (03-06-2019, 09:34 PM), mixedbrasil2014 (03-01-2019, 10:57 PM), Irah (03-05-2019, 09:15 AM), GeneralDJ (03-13-2019, 08:17 AM), DennisN (03-06-2019, 08:13 PM), langsail (03-15-2019, 11:46 AM), juanjo57 (05-05-2019, 04:36 AM)

Forum Jump:


Users browsing this thread: 1 Guest(s)