Battery power consumption question

stapeler

Hi. Hoping somebody can help me here. Voluntary organisation with remote building occasionally gets vandalised. No electricity for miles so have set up the following.
Mini CCTV recorder and mini Camera powered by two 12v 63ah batteries. Image quality is very good and operates on motion control. Happy enough with setup so far except batteries last a max of 8days.

The Recorder is 12v and consumes <2w (power expend <150ma ??is this stand by power?) It operates on motion control.
The Camera is also 12v and consumes 120mA.

The batters size is limited as an older person who runs the operation needs to be able to remove them for charging.

Both batteries were fully charged and lasted approx 8days. My calculations indicated they should last about 16days. Does this sound correct or should I be getting longer out of the setup?

Would a 10w pv panel be of any benefit in this situation or is there anything else that I could do to extend the time between charging?

Any advice appreciated.

Pete67

Are you using the two batteries in parallel or one at a time?

A 10W PV panel will give on average 4.4 Ah per day, dending on weather conditions and time of the year. This should be enough to cover a continuous load of up to 2.2W. However your setup is 3.2W minimum, so to be safe I would probably go for a 20W panel such as one of these: panel

You would also need a charge regulator to prevent overcharging the batteries, something like this: regulator

Connect the two batteries in parallel to give you a 12V 126Ah battery and you should not have to worry about charging batteries again. Make sure you put a suitable fuse/circuit breaker in circuit to protect the wiring in the event of a short, 12V lead acid batteries can deliver large fault currents which could easily start a fire.

Just a point on batteries, most 12V lead acid 'car' batteries are not designed for deep discharge, and will not last long at all if regularly discharged fully. There are deep cycle batteries designed for this application, but these tend to be quite expensive. However the 20W panel should keep the batteries near fully charged and there is no reason standard car batteries will not last for years if used in this way. Hope this helps.

stapeler

Thanks for that Peter.
Both batteries are running in parallel and I have a 5A fuse on the circuit. I will look into getting a 20watt Solar Panel and regulator. Ideally would like a set up that required zero intervention or perhaps only needed a real charge during the winter months.
Again thank you.