Not to happy with cc

[Tobym]

Hi again all I still havnt installed my solar yep but I do have all the components now. I eventually went for an outback fm60 I couldn't stretch to the  fm80. The thing I am very surprised at is that this top of the range cc does not have load terminals so will not regulate the batteries which I find ridiculous. Now I do know this is my fault not noticing this when researching the item. Now before I sell it again lol can someone convince me it's fine. Does anyone know if I can buy a battery bank load regulater preferably that could link with the cc. Thanks 

[kibi]

Hello Toby

I'm pleased everything is coming together. The FM 60 is a very good machine.
Most good (high capacity) charge controllers do not have load terminals on them. The main reason is that it is almost impossible to determine what loads the customer will be running, it could be 100A or it cold be 1000A, who knows. They could design for 1000A, but this brings about a whole new set of design complications and extra expense. You would also then need to run very thick cables into and out of your charge controller which is extra cable that is very expensive. It's better to just stick with the thinner (60A) cables and just have the charge controller perform charging tasks.
It is perfectly normal to connect your loads directly to the battery. A good inverter will monitor the battery voltage at all times and will cut out when the set low voltage limit is reached. I am not certain, but I think the Outback may have relay contacts that can be used when the battery voltage dips too low.
I think I have mentioned to you before that a battery monitor is essential in any serious installation. Good battery monitors will have alarms and a set of programable contacts, to drive bigger realys for instance, to disconnect the battery loads should the voltage drop too low.
Don't send the Outback back, it's a very good machine and will last you many years.

[Tobym]

Hiya kibi it's always great to hear from you thanks. Ok ill take that on board and I have kept it anyway as it is a great bit of kit. I will purchase d a battery moniter. On a unrelated subject I know his has been covered before but my panels state just under 5 amp but due to the mppt cc the current will be upped to potentialy 14 a am I correct the. In saying that the cables coming from the panels to the cc only need to be rated to say 20a and allowing for v drop as its about 25m run and then go a little over kill 4mm cable at 55a should be plenty. Thanks Toby

[Tobym]

Hiya kibi it's always great to hear from you thanks. Ok ill take that on board and I have kept it anyway as it is a great bit of kit. I will purchase d a battery moniter. On a unrelated subject I know his has been covered before but my panels state just under 5 amp but due to the mppt cc the current will be upped to potentialy 14 a am I correct the. In saying that the cables coming from the panels to the cc only need to be rated to say 20a and allowing for v drop as its about 25m run and then go a little over kill 4mm cable at 55a should be plenty. Thanks Toby

Could anyone confirm this for me thanks.

[SeanB]

4mm cable will be fine, lower loss of power to the MPPT converter is good. Just make sure the interconnects between the panels are 4mm if you are making them up yourself. The extra copper will help if you decide to add extra panels in the future. The current from the panel will be 5Z at best as this is what the panels deliver but the lower voltage drop along the long cable run will be good. Make sure the cable to the battery is 4mm as well, or you can use 6mm or even 10mm if the distance between the MPPT and the battery is over 10m.

Just remember that cable ratings are mostly done by voltage drop, and for most mains rated cable this is typically going to be a drop of 5% of 230V along a 30m length. At 24/48V however they still spec the same drop, but then it is a lot more significant, as the 5% of 230V is around 16V, which is a large amount if you only have 24/48V to play with.

With my simple system I used 4mm cable as I had a roll of it to hand, and the loop resistance is around 0.3R for the run of cable.