Tracer 40A MPPT

mike
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Posts: 4

Tracer 40A MPPT Apr 22, 2015 18:07:32 GMT -8

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Post by mike on Apr 22, 2015 18:07:32 GMT -8

Hi,

Using 4 renogy 100W panels no matter how I wire them I get 400W.

Series 75.6V @ 5.29A = 400W
Parallel 18.9V @ 21.16A = 400W
Series/Parallel 37.8V @ 10.58A = 400W

Input from panels to CC is 400W but is one wiring better than the others? Everything will be mounted on a heavy duty cart 24" x 48" and all wiring will be #8 from panels to CC to batteries. Cabling between batteries and inverter will be sized to inverter chosen

Can I charge 2 batteries at the same time and if so how would I wire them and what would be the charge applied?

The batteries are Trojan T1275 and here is the data sheet on them

www.trojanbattery.com/pdf/datasheets/T1275_Trojan_Data_Sheets.pdf

Thanks, Mike

Admin
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Tracer 40A MPPT Apr 24, 2015 14:37:44 GMT -8 mike likes this

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Post by Admin on Apr 24, 2015 14:37:44 GMT -8

Hello Mike,

You are right, no matter how you wire the panels, you will get 400W. The only advantages will come from one over the other depending on the charge controller you use. Some controllers cannot handle a high voltage so you will be forced into a series-parallel or parallel configuration. Which charge controller do you have?

You can charge two batteries at one time if they are connected together into a battery bank. You can connect them in series (to add voltage) or in parallel (to keep voltage the same and add capacity). Make no mistake here either though, regardless of wiring there is still the same amount of energy in both configurations.

Renogy Tech Support
SR

mike
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Posts: 4

Tracer 40A MPPT Apr 25, 2015 3:54:42 GMT -8

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Post by mike on Apr 25, 2015 3:54:42 GMT -8

using the Renogy 40A MPPT Controller.

using new Trojan 12V flooded batteries

If I want to charging a single 12V will the charger still apply 40A?

The 20hr rate is 150 Ah and I thought I read you only want to charge between 15-18% of the 20 hr rate which would be 22.5 to 27A.

What about 2 of these same batteries?

Is my thinking correct?

if wired in parallel the charger would see 12V and divide the current between the 2 batteries
If wired in series the charger would see 24V drop 12V across each battery but send the same current through both.

I'm new to solar and don't want to create a big hole in my back yard. So I figure I'll ask first.

Mike

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Tracer 40A MPPT May 9, 2015 11:43:33 GMT -8 mike likes this

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Post by Admin on May 9, 2015 11:43:33 GMT -8

Hello Mike,

The current output of the charge controller will depend on the input power. Just because it is a 40A controller does not mean it will always output 40A.

I would recommend consulting the battery manufacturer or spec sheet to see the individual battery's charging parameters.

The amount of current each battery will see will also depend on the wiring configuration. Just because two batteries are wired in parallel does not mean that the current gets split evenly.

This link has some good information regarding battery wiring.

www.smartgauge.co.uk/batt_con.html

After you find your battery's specs and the input power you plan to use, please come back so we can get this figured out.

Renogy Tech Support
SR

Chris DIYer
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Tracer 40A MPPT May 13, 2015 19:23:21 GMT -8 via mobile

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Post by Chris DIYer on May 13, 2015 19:23:21 GMT -8

Stay with higher voltages on both ends. I started off running everything 12v years ago. I am running near 100v VOC on my panels and 24v battery bank. 48v battery bank would be even better.

Off-Grid Home RE system
3.0KW Renogy RNG-100D panels (72v system)
1.3KW Sunpower e20 panels (72v system)
Midnite Solar Classic 150 (2), Classic 200
Outback Power VFX 3524 inverter/charger
Mate3 Communications Control Panel
Honda EU2000i Companion inverter/generator (2KW)
12 Trojan L16E-AC battery bank (1,100 amp/hours, 24v)
Reliance Controls Pro/Tran power transfer switch panel
Wireless TP-Link AC1900 router, Motorola DOCSIS 3.0 modem
BlueSeas 200-amp breaker

mike
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Posts: 4

Tracer 40A MPPT May 16, 2015 4:18:36 GMT -8

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Post by mike on May 16, 2015 4:18:36 GMT -8

May 9, 2015 11:43:33 GMT -8 Admin said:

Hello Mike,

The current output of the charge controller will depend on the input power. Just because it is a 40A controller does not mean it will always output 40A.

I would recommend consulting the battery manufacturer or spec sheet to see the individual battery's charging parameters.

The amount of current each battery will see will also depend on the wiring configuration. Just because two batteries are wired in parallel does not mean that the current gets split evenly.

This link has some good information regarding battery wiring.

www.smartgauge.co.uk/batt_con.html

After you find your battery's specs and the input power you plan to use, please come back so we can get this figured out.

Renogy Tech Support
SR

SR,

That link to Smart Guage is great..... I love when folks use pictures and speak plainly. In the beginning you don't need a lot of scientific notation but a couple of drawings and 30 words can speak volumes.

Right now I simply have 2 small banks both built like this.

2 150Ah in parallel
Interconnects are 13" 4/0 +/+, -/-
CC is wired to + of 1 battery and - of the second.

A very basic setup.

The link you provided gives me several options IF and when I need to add/reconfigure to suit my needs.

HERE"S A QUESTION:

My batteries have short terminals so adding a third lug is not an option. I imagine I could fashion a small copper bus in order to add another set of lugs. Again, only as the situation demands.

That link to Samrt Guage is a keeper.

Post by mike on Apr 22, 2015 18:07:32 GMT -8

Post by Admin on Apr 24, 2015 14:37:44 GMT -8

Post by mike on Apr 25, 2015 3:54:42 GMT -8

Post by Admin on May 9, 2015 11:43:33 GMT -8

Post by Chris DIYer on May 13, 2015 19:23:21 GMT -8

Post by mike on May 16, 2015 4:18:36 GMT -8

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