Magnum BTS-15

Does anyone know the nominal resistance of a Magnum BTS-15 temp sensor. I have an older MS2812 inverter and I have no way of adjusting the actual voltages used for charging. The gel setting does an absorb charge at 14.1V hich is too high for real longevity of East Penn gels. The maximum they should see is 13.8v. I've seen 14 yrs of service at 45% max discharge about 300 days per year. The batteries are still at 92% of their original capacity. I wish to substitute a pot for the temp sensor to adjust the voltage lower by 0.3V by faking the temperature. I have a separate temp alarm on each battery and they are in an air conditioned environment, so I'm not worried about temperature run-away.

Anyway, if someone knows or can measure the nominal resistance of the temp sensor and which two of the four pins are actually used for connection, it would be greatly appreciated.

Thanks, Kevin, K3RYL

Comments

  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Magnum BTS-15

    Welcome to the forum Kevin,

    I do not have a Magnum, so I cannot measure the resistance--I will bump the thread to see if anyone else can help. Have you tried asking Magum tech support (usually most vendors seem to do better with direct phone calls vs using their email contact).

    One question--Is your inverter compatible with the advanced remote control?

    http://www.solar-electric.com/inverters-controllers-accessories/inverters/maenin/recoandotac/mameadrecofo.html
    The ME-ARC is simple to use, yet allows full set-up of all the standard and advanced features available in Magnum inverters. The ME-ARC also has the option of controlling the advanced features of the ME-AGS-N Automatic Gen Start and the ME-BMK Battery Monitor Kit using a network connection to the inverter. This remote has convenient finger-tip operation, including the new one-knob programming. Note: All settings/setup menus in the ME-ARC are compatible with MS-PAE Series inverter/chargers. If you are using the ME-ARC with another inverter/charger (other than the MS-PAE Series), some features and setup menus may not be compatible with your inverter and will not function. Contact Magnum Energy to determine if a particular feature/setup menus provided in the ME-ARC are compatible with your inverter.

    Paying $240+ to be able to adjust the charging voltage does seem a bit excessive.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • k3ryl
    k3ryl Registered Users Posts: 5
    Re: Magnum BTS-15
    BB. wrote: »
    Welcome to the forum Kevin,

    I do not have a Magnum, so I cannot measure the resistance--I will bump the thread to see if anyone else can help. Have you tried asking Magum tech support (usually most vendors seem to do better with direct phone calls vs using their email contact).

    One question--Is your inverter compatible with the advanced remote control?

    http://www.solar-electric.com/inverters-controllers-accessories/inverters/maenin/recoandotac/mameadrecofo.html



    Paying $240+ to be able to adjust the charging voltage does seem a bit excessive.

    -Bill

    Bill,

    Thanks for the reply. Unfortunately my inverter is a very early model. To use the latest remotes, the inverter's control board needs to be replaced. Big bucks, plus a new remote on top of that, hence my workaround using the temp sensor. I have two Trace SW2512 inverter's that I have been using for years. Had the Magnum inverter as a backup but have never fired it up until recently for use in a second PV system, then ran into the charging voltage problem.

    I did ask Magnum about their BTS-15 specs but they would not give me the info. As a proof of concept I tried a pot in place of the temp sensor on one of my Trace inverter's and it worked perfectly. If I can't get a resistance reading for the Magnum BTS-15 from someone I'll just have to buy one to measure it myself. Guess I'm cheap but didn't want to give Magnum more $s since they haven't been very helpful so far.

    Thanks, Kevin
  • Blackcherry04
    Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: Magnum BTS-15

    I have never used a pot on a Magnum, only on a xantrex. I have one in the shop ( Magnum bts ) and was going to look at it this week. On a Xanterx you use the ( I think, this is without looking ) red on one side and the green and yellow on the other, black was not used, it's about 300 K ohms or so. The last one I made I used a 100k fixed resistor and 300K pot. That said I'v always had a SCP panel connected with a temperature read out.

    Not a new concept, it's been being done around the net for years. If your not in a hurry, I am going down on wed or thur and I'll post back.
  • k3ryl
    k3ryl Registered Users Posts: 5
    Re: Magnum BTS-15

    Blackberry,

    Thanks, no, not in any rush. Would appreciate any info you can dig up later. I figured it will save me a lot of messing around trying to determine the correct pins and pot resistance to use. Really appreciate the offer. So, I didn't invent something new, guess it's not surprising with all the smart people floating around out there!

    Kevin
  • SolarMusher
    SolarMusher Solar Expert Posts: 176 ✭✭✭
    Re: Magnum BTS-15

    Hi Kevin,
    Sorry for the dummy question, but did you try the custom settings (not gel setting) in your ME-RC?
    If you don't have one, I'm pretty sure that you can buy a new one and have it to work with your old 2812, Custom setting is really basic for all Magnum system.
    Good luck with that,
    Erik
  • boB
    boB Solar Expert Posts: 1,030 ✭✭✭✭
    Re: Magnum BTS-15

    Their BTS is 100K Ohms at 25 degrees C

    Negative temperature coefficient. The higher the temperature, the lower the resistance and vice versa.

    boB
  • Blackcherry04
    Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: Magnum BTS-15

    I'll defer to boB below ( he would know ) on the ohm's as my meter wouldn't work today. The active wires are the Black and Yellow, they are the two outside contacts on either side of the plug on the Magnum RTS.
  • k3ryl
    k3ryl Registered Users Posts: 5
    Re: Magnum BTS-15

    Thanks everyone for all the information. Been away for a few days but will give the "replacementi[PHP][/PHP]" temp sensor a try today and report back. I wish I had the custom settings on the RC that was mentioned but unfortunately the rev. Level of my 2812 and RC don't allow access to that menu item......wish it did. If this method with the temp sensor doesn't do the trick I'll be forced into an update. Thanks again everyone.

    Kevin