Battery Temperature Sensor placement

Coach DadCoach Dad Solar Expert Posts: 150 ✭✭
I'm in the process of doing the wiring for my off grid system.
The problem is: There are 5 things which are supposed to be connected to the negative battery terminal..
- Temp sensor for the Inverter/Charger
- Temp sensor for the Charge Controller
- Power for the Battery Monitor
- Voltage sensor for the Charge Controller
- Negative Battery Cable

I have 4 batteries in Series which make up a 24 volt battery bank... So I was thinking that I could connect the 2 temp sensors to 2 of the batteries in the middle of the series string... That would reduce the wires on the main negative terminal from 5 wires to 3...
Does anyone see a problem with that?

Comments

  • westbranchwestbranch Solar Expert Posts: 5,142 ✭✭✭✭
    Re: Battery Temperature Sensor placement

    does it sense only or draw power/create a ground?
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
  • Coach DadCoach Dad Solar Expert Posts: 150 ✭✭
    Re: Battery Temperature Sensor placement
    westbranch wrote: »
    does it sense only or draw power/create a ground?

    No... they sense the battery temperature.. That is why I don't see any problem with it
  • westbranchwestbranch Solar Expert Posts: 5,142 ✭✭✭✭
    Re: Battery Temperature Sensor placement

    Connect it at your leisure, towards the center of the bank would probably get a higher temp but that will lower the charge V's
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
  • VicVic Solar Expert Posts: 2,970 ✭✭✭✭
    Re: Battery Temperature Sensor placement

    CD,

    personally, I'd place all of the temp sensors midway down the side of one single battery near the center of the pack. Just tape them onto the side of the battery, and then place 1-ish inch thick styrofoam sheet, cut to about the width of the battery over the sensors. Tape or strap the styro onto the battery. This helps reduce the ambiant temp effects from influencing the measured temps. Not placing them on a battery terminal reduces the effects of high current flows with attendant temperature rise on the batt terminal, causing somewhat erronious temp readings.

    It is nice that you have a single string of batts, as multi strings can cause a dilemma in choosing the best battery to use as the sense site. YMMV, Vic
    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH [email protected], 11.1 KW STC PV, 4X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  25 KVA Polyphase Kubota diesel,  Honda Eu6500isa,  Eu3000is-es, Eu2000,  Eu1000 gensets.  Thanks Wind-Sun for this great Forum.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Battery Temperature Sensor placement

    Because it's going to be asked: what brand of controller & inverter have you got?
    Although temp sensors can be placed on battery posts they also are often stuck to the side of the battery. The difference will be small (and either way better than no BTS at all).

    And now a commercial for Outback's integrated system which would have one BTS stuck to the side of a battery and sharing the data between the controller and inverter via the HUB. Sometimes buying all from one manufacturer helps. :)

    For anyone having this sort of trouble, remember that your controller is the primary charge source with an off-grid system so if necessary favour putting the BTS on that over the inverter if it comes to either/or.
  • Coach DadCoach Dad Solar Expert Posts: 150 ✭✭
    Re: Battery Temperature Sensor placement
    Because it's going to be asked: what brand of controller & inverter have you got?
    .

    I have a TriStar MPPT-60 Charge Controller and Magnum MS-4024PAE Inverter
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