Charge Controller - Load Hot Water?

[Chetwode Ram]

Hello, I am a complete novice solar moron so please reply as if you are speaking to a toddler.
I need to have 4 hours a day approx of a 300w 12v immersion element heating some water in a hut. I have an Epever Triron 40amp/100v controller and 3 x 130w panels, charging 2 x 200ah batteries connected in parallel. I wanted to wire the hot water to the battery via an idiot proof 12v timer switch but they don't seem to come with more than a 16amp fuse (I need 25 I think). A man in a shop started talking about a relay and showed me a diagram, which made my small brain hurt. Can I A) Put 25 amps through the load terminals on the controller instead and set it to come on for 4 hours in the day time every day or just to come on when the battery is full (it only does LED lights so should often be full)? The manual is not clear on this. OR b) buy a mechanical, non-digital or powered rudimentary timer switch in 240v and wire it in to the 12v batteries.
Any help greatly appreciated.

 

[SamDeleted]

Hello, I am a complete novice solar moron so please reply as if you are speaking to a toddler.
I need to have 4 hours a day approx of a 300w 12v immersion element heating some water in a hut. I have an Epever Triron 40amp/100v controller and 3 x 130w panels, charging 2 x 200ah batteries connected in parallel. I wanted to wire the hot water to the battery via an idiot proof 12v timer switch but they don't seem to come with more than a 16amp fuse (I need 25 I think). A man in a shop started talking about a relay and showed me a diagram, which made my small brain hurt. Can I A) Put 25 amps through the load terminals on the controller instead and set it to come on for 4 hours in the day time every day or just to come on when the battery is full (it only does LED lights so should often be full)? The manual is not clear on this. OR b) buy a mechanical, non-digital or powered rudimentary timer switch in 240v and wire it in to the 12v batteries.
Any help greatly appreciated.

300w / 12v = 25amps - you are correct

1 x 12V Timer Switch Timer Controller LCD display,program/programmable 25A amps | eBay

Resistance 25A. Programmable number Relative humidity Clock error (It is impossible to drawback the evaluation). If there's an exception, we will inform you. -10 - 50 â. 1 minute â 168 hours.

www.ebay.co.uk

This looks suitable?

 

[Chetwode Ram]

300w / 12v = 25amps - you are correct

1 x 12V Timer Switch Timer Controller LCD display,program/programmable 25A amps | eBay

Resistance 25A. Programmable number Relative humidity Clock error (It is impossible to drawback the evaluation). If there's an exception, we will inform you. -10 - 50 â. 1 minute â 168 hours.

www.ebay.co.uk

This looks suitable?

Thank you very much. I've ordered one.

 

[Jordi]

300w / 12v = 25amps - you are correct

1 x 12V Timer Switch Timer Controller LCD display,program/programmable 25A amps | eBay

Resistance 25A. Programmable number Relative humidity Clock error (It is impossible to drawback the evaluation). If there's an exception, we will inform you. -10 - 50 â. 1 minute â 168 hours.

www.ebay.co.uk

This looks suitable?

Say there was a long cable between the timer and the resistive load through which 0,5A current are heat dissipated OR that the battery voltage was 11,5V. Is the timer limiting the current to 25A or can the current slightly surpass the 25A and damage or not the timer?

I did not understand what capacitance load meant here. Can you please explain?

 

[Chetwode Ram]

https://www.ebay.co.uk/itm/303020514621

I've gone for this one, which claims 30amps can go through it so hopefully OK but we'll see. The cable will be 3m or so. I can't explain capacitance load unfortunately! But thanks for the response.

 

[SamDeleted]

https://www.ebay.co.uk/itm/303020514621

I've gone for this one, which claims 30amps can go through it so hopefully OK but we'll see. The cable will be 3m or so. I can't explain capacitance load unfortunately! But thanks for the response.

Yea 25 amps through a 25a timer is pushing it ( I'd probably do it but not best practice)


30amp is fine , Glad you're sorted!

 

[efficientPV]

Chances are your relay will burn up and that arrangement will kill the batteries. 12V heating is just too much current and losses are high just getting to the heating element. Plenty examples of relays rated for more current than that burning up contacts from that current. Refrigerators and heaters are real battery killers, any control that doesn't monitor battery voltage will cause problems eventually. Heating from batteries interferes with charge cycles and battery will suffer from never getting a full charge.