12v timer for solar powered water pump - electronics experts please set me straight

[open roader]

I live on 6 acres with 2 ornamental dams (deep water ponds). In winter one dam fills with roadside runoff, the other dam is isolated and I use a 12v solar powered pump to trickle feed into the isolated dam to keep it's level respectable.

I burnt out my previous pump as it was not designed for 'continuous duty' - my bad. The pump was fit to deal with the lift/head and flow rate, just not designed to run all day. I'm pumping into a 2" internal diameter pipe so friction loss is not an issue either.

The pump was replaced last week with a heavier duty pump which is designated 'continuous duty' but continuous duty is stated at 6hrs continuous operating per day. I can live that no problem.

However, at present my partner is on timing duties switching the pump on when the sun hits the solar panels and off after 6hrs of running.

I'd like to know if I can fit an automatic timer to my 12v set up. Ideally it would have multiple timing programs so I could allow the pump to switch off for say 10-15 mins to allow it to cool down before kicking back in again.

I'm unsure if something like that exists as I do not run the pump off a battery - just straight off 4 x 12v 160W 8amp panels that are parallel wired. Does a timer exist that has something like a built in battery as I don't fancy maintaining an external battery, no matter how small if I can help it.

Also should I be running the power to the pump via a current controller unit - too much amperage for my pump?

Any instruction is greatly appreciated.

[Mabouya]

How about this?

Edit: It's sold out, but maybe you can find one just like it elsewhere.

https://www.solarpanelstore.com/prod...imer-prgtmr12v

When you have a 12-Volt system and you need a timer to control your loads, the Flexcharge 12 VDC Programable Timer is your best option. The digital timer keeps track of the day of the week as well the time in minutes. With so much accuracy it virtually can turn on and off any load.

It is important to note that the Flexcharge timer can control 120 VAC loads; however, the timer needs to be powered by a 12 VDC circuit. The timer includes a rechargeable battery to keep the time when the power source is off.

It can only control one load at the time and it allows you to program 8 events for that load.

The Flexcharge digital timer is a 7-day, 8-event digital clock based programmable load controller. Eight ON and eight OFF events can be programmed independently, each with its own unique timing pattern.

It includes a replaceable internal battery (batteries may need to be replaced) which maintains the clock and programmed memory in the event of a system power failure for up to 3 months. Consumes less then 3mA in standby mode.

The internal DPST (double-pole-single-throw) relay switch can turn one load on at the same time that it turns another load off. The timer switch can handle up to 8 amps of inductive load or up to 16 amps of resistive load, at 6 to 36VDC or 120VAC. The timer requires 12V DC or AC to operate. It is reverse polarity protected. The manual override allows the user to turn the load ON or OFF as desired. Easy to use terminal block for wiring; dry contacts.

Dimensions:
Width: 3.9"
Height: 3.8"
Depth: 2"

Example of use: use one ON event to have a light come on at 7 pm every day then use seven OFF events to turn the light off at a different time each day.

[Peter Polack]

If you don't find the exact kind of timer you're looking for, perhaps you might be able to use a Charge Guard.

Programmable via internal DIP switches, you'd only have to apply 12V turn on once a day. The DIP switch programmable timing would begin countdown and remove 12V after the programmed period of time.

Of course, the next day you have to turn your switch off then on to restart the cycle.