Using the inverters dry contact to switch a battery

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sunseeker

New member
Joined
Aug 30, 2017
Messages
20
Hello forum,
I have a question concerning the dry contact that my Mpp Solar Pip-2424MSE1 switches when it reaches the batteries' high or low voltage threshold.
I want to use the contacts to switch a relay that will connect or disconnect the 7S battery to another load.

The manual says that one can run 250V/3A through the contacts, but I was wondering if I can just also use a 12V/1A DC power supply to operate a relay.
I want to switch the 7S battery which operates a second load at a maximum of 20A. Can someone recommend a relay for this use as an example?
Should I also integrate a initial current limiter, so that the relay won't get damaged by the current spike when switching on?

Thank you very much for any hints or advice!
 

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OffGridInTheCity

Active member
Joined
Dec 15, 2018
Messages
1,862
Hello forum,
I have a question concerning the dry contact that my Mpp Solar Pip-2424MSE1 switches when it reaches the batteries' high or low voltage threshold.
I want to use the contacts to switch a relay that will connect or disconnect the 7S battery to another load.

The manual says that one can run 250V/3A through the contacts, but I was wondering if I can just also use a 12V/1A DC power supply to operate a relay.
Yes

I want to switch the 7S battery which operates a second load at a maximum of 20A. Can someone recommend a relay for this use as an example?
Should I also integrate a initial current limiter, so that the relay won't get damaged by the current spike when switching on?

Thank you very much for any hints or advice!
This one works for me for lower amp contactors - https://www.amazon.com/gp/product/B010L02RUO/ref=ppx_yo_dt_b_search_asin_title It says 80a but more like 40a max for daily switching.

For high amps I use a Gigavac as you can find them at 'reasonable prices'. Gigavac makes every kinds of coil voltage and range of amps and some have power saving coil/latch electronics. But as an example, here's a simple 12v coil with 350adc contacts - https://www.ebay.com/itm/154649476035?hash=item2401d3bbc3:g:w50AAOSwc1VhN6P4 Here's a PDF with specs for the ebay example - https://www.gigavac.com/sites/default/files/catalog/spec_sheet/gx14.pdf - its 0.23 A coil @ 12v.

There are others - these are just the ones I found during my DIY work :)
 
Last edited:

sunseeker

New member
Joined
Aug 30, 2017
Messages
20
Thank you OffGridInTheCity! I found a suitable relay now and am thinking of building a rush in current limiter with the help of a thyristor and a time delayed relay to bypass it after a few seconds.
 
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