batteries too full?

[DeanS]

erm.....

 

my son went on his desktop for 5hrs last night. ( about 50ah usage)

he went to college today.

the engine (some cruising this morning) and good solar charged his batts all day.

The sun went down ages ago

His batts are measuring 13V at 10pm at night.

 

Is it possible to overcharge batts?

The MPPT solar controller shuts down and stops delivering current early in the day.

 

He's now away from college for 10days , so will be using the batts more, and they probably wont get fully charged again for some time.

 

I was just wondering if 13V was acceptable (no load)

 

 

It COULD just be the aftercharge from receiving about 13.9V for most of the day.

 

[Grace and Favour]

Dean, you'll have to buy the kids a new XBox each, and fit an electric jacuzzi to use up the extra 'leccy

[Tony Brooks]

It takes ages for the surface charge and acid stratification to normalise if there is no load on the batteries so did anything get drawn off them or not. The solar would have been providing an elevated voltage till after 9pm today.

 

It is possible to overcharge batteries but not if the voltage control is suitable and I would hope your controller is BUT remember what Tim found with a supposed Ebay MPPT controller. If yours came from there I would be taking great care to monitor the charging voltage and would not want to see it much higher than 14.4 volts at any time except when/if it does an equalisation charge.

 

If it is trying some form of adaptive charging I would not be confident it is not fouling up but I doubt it.

 

At least it seems your new battery setup is working for you.

[Paul C]

With a proper MPPT controller, properly set up for your battery type, its not possible to overcharge the batteries.

 

BUT its possible that at certain times of year, you'll have an excess of solar generation capability, compared to power consumption, which is what I think you'll be experiencing now. Remember, in spring (earlier spring) and autumn, this will gradually decline and in winter, you're likely consume more than you generate from solar.

 

Basically, you size solar and that sets how many months per year you're more/less balancing generation and consumption.

[Tuscan]

Bizzard will be along shortly with his design to harness all the canal based excess solar power anticipated this summer to the National Grid