Solar Pond Pump - is there any point in having an accumulator battery?

[GillObrien]

Hi all,

I have a small garden pond with two fountains:

- one small run, with a floating pump just under the water surface that contains a battery. The fountain runs all day when there is sun, and once there isn't enough it runs 10 seconds every minute until the battery runs out. The solar panel face south, so it probably runs from 10am to 6pm continuously, then another hour on and off, and the same the morning.
- one filter - this is connected to a larger battery, like this, and in theory I bought this because I wanted to be able to run the fountain later at night. However, the system favours the battery charge over the fountain, and therefore does not operate the fountain at all until the battery reaches a threshold level. In full sun today, the battery was still not charged at 6pm (25degrees today and not a cloud in the sky), so the fountain hasn't run all day. If it doesn't reach the threshold level it doesn't operate. I only installed it this weekend, and the first few days it worked, but I don't know if this is because the battery was fully charged before delivery. The system has an LED indicator as follows:
- red - Battery discharged and system off
- red/green flashing - battery charging (I have never seen this)
- green - ready to go

There is another indicator called Charging that goes orange when charging. This is always orange, but the system indicator stays red. In the Troubleshooting in the manual it says that this means the accumulator has not reached this threshold.

Does this seem right? I would have thought 6 hours in direct sun would be enough. And even at this length of time it is pointless to run the sytem for 6 hours to charge the battery, to run it for 3 hours, when I could just connect it directly to the solar panel and run it from 10am to 6pm. What does the accumulator battery add in this case?

Many thanks,
Gill

 

[Alec_t]

Does this seem right?

Not to me. Sounds like the battery capacity and solar panel size are not well matched.

 

[GillObrien]

Not to me. Sounds like the battery capacity and solar panel size are not well matched.

I bought it as a kit so you would hope so! I put the specs below.

It looks like the solar panel is 10w, the pump uses 4 to 13W, the power of the solar panel is 10Wp (whatever that is). I can't find anything on the battery.

 

[Rodders53]

Google translate of the linked device suggests it's a 6V 3.2 Ah lead acid battery.
The solar panel is 8 Watts (peak), 8.64 Volts and 0.926 Amps.

See the data sheet from a typical battery of that capacity. https://www.tayna.co.uk/industrial-batteries/leoch/lp6-3-2/
The panel voltage is too high at peak (but may well be regulated down to a safer 7.1 to 7.5V) and the current is pretty much the max permitted for charging that capacity of battery. It will likely take a minimum of 3-4 hours to recharge from 50% discharge (hopefully the circuit prevents a deeper discharge as that wrecks lead acid batteries over time).

Unless it has an extremely good charge regulation and discharge prevention circuitry in the system the likelihood is the battery is dead Jim and beyond recovery. Especially if it has been out all winter and deep discharged overnight repeatedly.
Although a mains operated 6V smart charger would be the first port of call to try with the battery if you have one..

If the battery box is in the sun it will not do it any good either from heat.


If it is a 12V 7Ah battery and pump then the above still mostly applies if you double the Volts and find the spec of a 12V 7Ah battery.

 

[GillObrien]

This is what it says regarding charging.

 

[GillObrien]

Google translate of the linked device suggests it's a 6V 3.2 Ah lead acid battery.
The solar panel is 8 Watts (peak), 8.64 Volts and 0.926 Amps.

See the data sheet from a typical battery of that capacity. https://www.tayna.co.uk/industrial-batteries/leoch/lp6-3-2/
The panel voltage is too high at peak (but may well be regulated down to a safer 7.1 to 7.5V) and the current is pretty much the max permitted for charging that capacity of battery. It will likely take a minimum of 3-4 hours to recharge from 50% discharge (hopefully the circuit prevents a deeper discharge as that wrecks lead acid batteries over time).

Unless it has an extremely good charge regulation and discharge prevention circuitry in the system the likelihood is the battery is dead Jim and beyond recovery. Especially if it has been out all winter and deep discharged overnight repeatedly.
Although a mains operated 6V smart charger would be the first port of call to try with the battery if you have one..

If the battery box is in the sun it will not do it any good either from heat.


If it is a 12V 7Ah battery and pump then the above still mostly applies if you double the Volts and find the spec of a 12V 7Ah battery.

It has only been out for three days . It is apparently protected against deep discharge or overload.

It was in the sun yesterday but I moved it. Could this have finished it off? If I switch the system off and on again, the LED is green and it starts working, but the instructions say this is because it overrides the threshold.

 

[GillObrien]

Google translate of the linked device suggests it's a 6V 3.2 Ah lead acid battery.
The solar panel is 8 Watts (peak), 8.64 Volts and 0.926 Amps.

See the data sheet from a typical battery of that capacity. https://www.tayna.co.uk/industrial-batteries/leoch/lp6-3-2/
The panel voltage is too high at peak (but may well be regulated down to a safer 7.1 to 7.5V) and the current is pretty much the max permitted for charging that capacity of battery. It will likely take a minimum of 3-4 hours to recharge from 50% discharge (hopefully the circuit prevents a deeper discharge as that wrecks lead acid batteries over time).

Unless it has an extremely good charge regulation and discharge prevention circuitry in the system the likelihood is the battery is dead Jim and beyond recovery. Especially if it has been out all winter and deep discharged overnight repeatedly.
Although a mains operated 6V smart charger would be the first port of call to try with the battery if you have one..

If the battery box is in the sun it will not do it any good either from heat.


If it is a 12V 7Ah battery and pump then the above still mostly applies if you double the Volts and find the spec of a 12V 7Ah battery

Looking at all the info it seems that I should have paid more attention to the battery specs. I think it makes no sense to have the battery because it will take too long to charge.

I should have chosen a battery that had an option to run the pump off the solar panel only and use the excess to charge the battery.

Can I just connect the pump directly to the solar panel?