Solar - what to buy?

[Tom and Bex]

We have 4 x 250w household panels wired in series, but remove 2 of them in the summer. Only paid about £100 each for them and easily paid for themselves in a couple of years.

It's pushing right on the limit for the 40a Tracer, both in terms of voltage and current. Have occasionally seen around 40a in full sun on bright spring days (and also in mid summer with 2 panels) but the Tracer will limit current to max of controller even if the panels could supply more. Have also once seen a high voltage cut off warning, but only happened once, and in full sun on very cold spring day. 

 

[Richard10002]

11 hours ago, smileypete said:

Out of interest when the Trojans are equalised at the recommended voltage, what current do they take?

Very useful... particularly the bit about keeping the 100W panel and PWM controller as is!

When charging at 15.5V, (the max my charger will provide), IIRC, the Trojans steady at about 4 or 5A, and it doesn't drop below that after 3 or 4 hours.

[jam]

On 12/03/2017 at 13:12, Richard10002 said:

Bimble offer a meter for about £25, but I'm not sure what it does http://www.bimblesolar.com/offgrid/mppt/MT50-meter 

For the money I would take it. it will give hours of fun and also help in the setting up of the controller

[smileypete]

On 13/03/2017 at 22:33, Richard10002 said:

Very useful... particularly the bit about keeping the 100W panel and PWM controller as is!

When charging at 15.5V, (the max my charger will provide), IIRC, the Trojans steady at about 4 or 5A, and it doesn't drop below that after 3 or 4 hours.

Sorry for late update...

Might be possible to use the existing 100W panel to eq the batts then, just use a double pole switch to connect it to the battery side of the PWM with a blocking diode if needed, and of course a fuse at the batt end.

Another way would be a double pole relay if you're happy to do it automatically, might be possible to run the relay from the load output of the MPPT if it can be set for a fairly short time. Of course the batt levels need a close eye kept on them too...