Panels producing too much voltage

[Sunking]

You are welcome.

[symbiosis]

Thanks for those calculations Sunking, I've bought the charge controller linked on the first page that does have the ability to set those so will be replacing my existing one with it ASAP

[Sunking]

I can help you with the voltages, but I doubt your controller has the ability to be set correctly. Additionally some of the claims the manufacture makes is let's just say optimistic. Your battery is made for Float Service in a UPS.

Set the Bulk/Absorb to 14.6 volts and Float to 13.6 volts.

[symbiosis]

Thanks again - here's all the info I can find on my battery http://www.systems-sunlight.com/wp-c...-12v-200ah.pdf

[Sunking]

Thanks. The charger that was suggested (and the one I linked to) states it has Float Charge: 13V (default,adjustable) - is that what I need to prevent this happening and (as its adjustable) its 13 v optimum?

Float Voltage is not 13.0 volts. It depends on the battery and will be between 13.2 to 13.8.

[jflorey2]

So if my battery ends up fully charged, is this constant connect/dsconnect actually doing any harm to my system?

It's how it is supposed to work, so no - not much.

[sensij]

Thanks. The charger that was suggested (and the one I linked to) states it has Float Charge: 13V (default,adjustable) - is that what I need to prevent this happening and (as its adjustable) its 13 v optimum?

I think you'll find that the Amazon description is incorrect, and that the charger documentation will indicate 13.7 V default for float. That is a typical value for lead acid... if your battery manufacturer has a recommendation for your specific batteries, you should follow that.

[symbiosis]

Thanks. The charger that was suggested (and the one I linked to) states it has Float Charge: 13V (default,adjustable) - is that what I need to prevent this happening and (as its adjustable) its 13 v optimum?

[inetdog]

So if my battery ends up fully charged, is this constant connect/dsconnect actually doing any harm to my system?

A bit of harm to the batteries, not to the panels, wiring or inverter. It is contributing to unnecessary cycling (although micro-cycling) of the battery and it is either steadily overcharging or failing to charge properly, since it is not maintaining a proper float voltage.

[symbiosis]

So if my battery ends up fully charged, is this constant connect/dsconnect actually doing any harm to my system?

[symbiosis]

Same controller, so yes suitable. Don't know the exchange rate, what's that in USD$?

Around $30

[Sunking]

At night, my controller tells me my battery is around 12.8 v

That would be a FULLY CHARGED BATTERY

[littleharbor]

Same controller, so yes suitable. Don't know the exchange rate, what's that in USD$?

[symbiosis]

I'm in the UK - does this look suitable please https://www.amazon.co.uk/MOHOO-12V-2.../dp/B01KV1GTQG

[symbiosis]

Thanks again for the replies and what you say makes sense to me as well and explains the off/on cycling. My total panel wattage is just under 300 (so small) but think I will need a min 30 amp controller? So (to put it into simple terms) what is happening is that during the summer my panels are quickly charging my battery up past 14.2 v (the safety voltage overload disconnect on my existing controller), which then prompts it to disconnect the solar input (as it should) but then the battery voltage immediately drops below 13.4 v (the re-connect setting) and so the cycle begins again.... What does the float option do and (in this circumstance) what should I be setting it at please?