12 hours ago, GreenFields said:

Laymans' thoughts & thumbsucks. In the heart of winter I'd guesstimate around 3-4 hours equivalent

Indeed, this is highly dependent on where you live. 5 hours is actually a good average. In summer it goes as high a 6.5 where I live, and in winter, of course, it can be quite low. The only issue for me is that I installed the PV system in 2013, and since around 2014 we haven't really had a proper Cape Winter in Cape Town... so I don't really have practical numbers on that situation.

17 hours ago, ProjectGKR said:

The battery cycle use range is 14.6 to 14.8v. Gives room to up the morning sun mppt side. (With a voltmeter I have found that the mppt shows 58v but at the battery bank it is 58.4V)

Also is the battery balancer a good place to start with as well? Planning on ordering it first thing  in the morning.

I spotted the same. On the Microcare MPPT it shows 56v but on my MLT inverter it will show on the MPPT solar input 56.4v. This can be a bit of a problem it you running Lithium with a BMS that can disconnect, and i'm planning to run 2 x 60 amp mppt's of them on lithium. 

Something I spotted on there website, is that you can actually connect the MPPT to a pc an do change and check it. here is the link, check the bottom of the post: http://microcare.co.za/data-acquisition-application/

All the protocol info there. I have the pins layout of the RJ12 that go's in to the MPPT. Who maybe got some info how the Microacare data acquisition cable looks inside.

Maybe someone can use the protocol script to write a script for a Pi unit. 

Edited November 12, 20196 yr by Gerlach

17 hours ago, ProjectGKR said:

The battery cycle use range is 14.6 to 14.8v. Gives room to up the morning sun mppt side. (With a voltmeter I have found that the mppt shows 58v but at the battery bank it is 58.4V)

Also is the battery balancer a good place to start with as well? Planning on ordering it first thing  in the morning.

I spotted the same. On the Microcare MPPT it show 56v but on my MLT inverter it will show on the MPPT solar input 56.4v. This can be a bit of a problem it you running Lithium with a BMS that can disconnect, and i'm planning to run 2 x 60 amp mppt's of them on lithium. 

Something I spotted on there website, is that you can actually connect the MPPT to a pc an do change and check it. here is the link, check the bottom of the post: http://microcare.co.za/data-acquisition-application/

All the protocol info there. I have the pins layout of the RJ12 that go's in to the MPPT. Who maybe got some info how the Microacare data acquisition cable looks inside.

Maybe someone can use the protocol script to write a script for a Pi unit. 

Edited November 12, 20196 yr by Gerlach

Just an update.

I installed the balancers on Friday morning. Orange LED on for all 3 balancers and Alarm state triggered as well on one of the balancers. Managed to borrow a Victron Smart Charger and charged all the batteries linked to the balancer that was in alarm state (as mention in the documentation as one of the steps to remedy alarm) overnight.  Started system again Saterday morning but the Alarm state just moved to the next balancer. Decide to run the system as is an let it do a full cycle due to the fact that I started the system on Friday morning basically fully charged. This morning at 5:15Am it as still at 49.1V and when the cycel started I only managed to get one balancer to switch on it's Orange LED when  it was already on 58V and the amps was at about 15/16 on the Mppt's. No alarm state which I recon is a good sign. Interesting is that that extra negative to negative connection between the 2 banks for each battery as part of the Balancer install also seems to greatly help to get a better balance between the banks. 

I just now need to find a sweet spot to get the 2 mppt's to switch to float a bit closet to each other as the West side Mppt went into float at about noon leaving the East to still try and boost. Currently both Mppt's are set to 14.5V, 1 hour scan interval & charge < 6amps, 90% charge limit.

I also installed the BMV-700 Battery Monitor.

Thanks again for everyone's input

I dont think your mppts will go to float at the same time, mine certainly dont, and there is only 20 degrees difference between the arrays. I dont think it is neccesarily a problem as it means that the battery is in absorb charge as it has stopped taking all of the  current you are trying  to push in there. If the charging is done by one mppt or the other is probably moot. If you switch on a large load when the mppts are In that state you will see the watts pick up on both of them.

2 hours ago, DeepBass9 said:

dont think your mppts will go to float at the same time, mine certainly dont

Correct, but what happens is that the one goes into float and then then other one again works harder and boost for another hour, working to build up again. isn't this potentially resulting in 2 absobtion charges being applied in the same day?

 

2 hours ago, DeepBass9 said:

If you switch on a large load when the mppts are In that state you will see the watts pick up on both of them.

I noticed this as well, if one in float and other boost, a big load I indeed see the watt picking up.

In my case the one goes into float at zero amps, so is doing nothing, then the other one stays in absorb, and goes to float eventually. I don't think it is a problem. In your case with east and west arrays do you get more of a dip at midday? I still don't think that is necessarily a problem, as the batteries should be close to full if the MPPTs are arguing about float or not.

9 minutes ago, DeepBass9 said:

I still don't think that is necessarily a problem

I agree, don't fret.

On 2019/11/18 at 10:35 AM, DeepBass9 said:

I still don't think that is necessarily a problem, as the batteries should be close to full if the MPPTs are arguing about float or not.

Changed both the Mppt's to boost at 14.6V (the AGM battery specifications indicate 14.6 - 14.8) and now the Morning Side Mppt seems to hold on longer before switching to Float, giving the Sun time to better shift over to the after noon side panels and giving the Afternoon Side time to still Boost with good input from the panels.

Thanks again for everyone's input

Why not boost to 14.7 or 14.8?

9 hours ago, DeepBass9 said:

Why not boost to 14.7 or 14.8?

Asking myself the same thing now. Initially I measured the voltage on each battery during boost and some batteries was showing a higher voltage, and then I ended up setting it at 14.5V.

With what I learned sofar, 14.7V would probably the best mid way looking at Battery info:
Cycle Use: 14.6-14.8V 
Standby Use: 13.6-13.8V

Maybe up the Float to be 13.7V aswell

I don't recommend you guess the float voltage, I think you can nail it spot on. (Probably with most batteries).

In my messing about with things, I have learned to watch the battery voltage vs current until I found a steady voltage that was basically a fluctuating 0-30Watt(ish) draw.

I set this as my float voltage.

I also used this method to fine tune the temperature coefficient.

Now when the batteries are at float at any temperature they basically draw just 10's of Watts ( 8strings of 4x100Ah LA's - 4 yrs old).

1 hour ago, phil.g00 said:

( 8strings of 4x100Ah LA's - 4 yrs old).

That is impressive, because batteries of that size are not renowned to last very long. Although, I ran a 12V system on a 12V 100Ah deltec battery for about 3 years with no concerns about how many times I drew the battery to completely empty!

Edited November 20, 20196 yr by DeepBass9

Hello

So after 3 months 2 batteries again has gone bad. One in each bank.

I have now contacted microcare to find out if I can get updated firmware for my Mppt's and to also get it ready for Li Ion.

What size Li Ion would be the best for my current setup of 2x 60A mppt's and 9x 300W panels facing east and 9x 300W panels facing west? I am not worried about going off grid, I just want something that is reliable as I am currently spending all my capital on batteries.

Thanks

How long is the warranty on current batteries? 

2 minutes ago, Richard Mackay said:

How long is the warranty on current batteries? 

7 of the 8 batteries in my current setup are out of warranty as I purchased it in May 2018. I went down from 3 to 2 banks Nov last year (only purchased one new battery to get to 2)

The 2 batteries that failed are all the May 2018 purchased batch

So only 1 year warranty?

What battery? Make?

2 hours ago, Richard Mackay said:

So only 1 year warranty?

What battery? Make?

Page 1, first post...

Sorry to hear that. Batteries are not cheap.

Maybe lithium batteries will work out better for you.

9 minutes ago, DeepBass9 said:

Maybe lithium batteries will work out better for you.

That's what I thought as well.