Renogy rover 40 amp MPPT charge controller questions

[jakubman1]

Hey guys i have a Renogy Rover Li 40 amp charge controller and im going to wire it with 4 100 watt renogy mono panels. My question is Can i add 1 more 100 watt panel making it 500 watts ? Here are the specs of the panels i have : Maximum System Voltage: 600VDC UL
Open Circuit Voltage: 22.5V
Short Circuit Current: 5.75A
Opitmum Operating Voltage: 18.9V
Optimum Operating Current: 5.29A
And the Charge controller here is the link on Amazon : https://www.amazon.com/Rover-Solar-C...5278235&sr=8-2

I will be wiring them in Parallel. As for batteries . I built 1 120ah Ford Cmax energy pack and going to add another wired in Parallel also making 240ah

Thank you very much for your input! Im building a camper from a 6x12 enclosed trailer. Here is what i have for electrical stuff so far. Im not done !

[Ampster]

I presume those are Lithium and four of them in series gets you about 15 to 16 Volts. What is the Wattage of your Inverter?

[littleharbor]

The only way to wire 5 panels is ALL in parallel, or All 5 in series. All 5 in parallel defeats the point of having an MPPT controller. All5 in series may be too high of voltage for the controller to handle. What is the max Voc. for your controller? You may be better off with 4 in series 4s or series/parallel 2s2p. OR 6 panels wired 3s2p or 2s3p. Keep in mind 2s3p will require fusing on each string.

[jakubman1]

My inverter is a 2000w Xantrax Pro sine wave. Ive been able to run my mini fridge off of it . I bet i can run my Dometic 13,500btu rooftop ac on them only for a short time but i will need a bigger inverter.

My max Voc is 100 volts on the charge controller. I will be wiring these up in all Parallel giving more amps to the batteries . So can i use 5 solar panels in parallel ? It says it can handle 520w at 12v.

Yes the battery pack i built are from a Ford hybrid car which use Lithium. They are called ford Cmax energi. I can safely drain these down to 11.5 volts and charge them to 16 volts. A lot of people use them in car audio because you can pull A LOT of amps out of them for a few seconds and put back A LOT amps into them. Since ill just be using them to run some led lights,fantastic fan and a fridge ill be fine. When i build my second battery pack ill have 240ah of power. Ive done a lot testing on these cells. I saved A LOT of money just building my own battery packs which are better than buying them off the shelf. They want like $1,000 for 100ah of lithium i spent like $400 on one pack. And if 1 or a few cells get bad i can easily fix that. They weigh roughly 40lbs too!

Thank you for the help and input !

Jakub

[Ampster]

...
Yes the battery pack i built are from a Ford hybrid car which use Lithium. They are called ford Cmax energi. I can safely drain these down to 11.5 volts and charge them to 16 volts. A lot of people use them in car audio because you can pull A LOT of amps out of them for a few seconds and put back A LOT amps into them. ......

I use Nissan Leaf modules which are the same NMC chemistry. My modules arel from different cars so I use conservative voltages for longer life and safety. I only charge them to 3.95v per cell and only discharge them to 3.5v. I assume your packs are 5p4s.

Is there a reason you chose to go with two packs instead of one 10p4s pack?

[jakubman1]

I use Nissan Leaf modules which are the same NMC chemistry. My modules arel from different cars so I use conservative voltages for longer life and safety. I only charge them to 3.95v per cell and only discharge them to 3.5v. I assume your packs are 5p4s.

Is there a reason you chose to go with two packs instead of one 10p4s pack?

I just chose them because it was available to me. You can buy these at the junk yard and take them apart easily.

But back to my question... Can i add 1 more panel to my system ?

Thank you very much !

Jakub

[Ampster]

......

But back to my question... Can i add 1 more panel to my system ?

Based on an earlier response, you would have more flexibility with 6 panels. Your batteries have the capacity to take the extra Amps.

[jakubman1]

Ok cool. So my answer is YES i can add 1 more 100 watt panel and ill have 5 in total . And YES my charge controller can handle 5 100 watt panels wired in Parallel according to my responses here !

Thanks guys!

Jakub

[littleharbor]

Ok cool. So my answer is YES i can add 1 more 100 watt panel and ill have 5 in total . And YES my charge controller can handle 5 100 watt panels wired in Parallel according to my responses here !

Thanks guys!

Jakub

You don't understand how an MPPT controller works. They will boost the current as they lower the high voltage to the system voltage. All 12 volt panels in parallel isn't the way you want to wire your array. Either go 2s2p or 2s3p or 3s2p.So stay with 4 panels or add 2 more. Not that 5p won't work but it's not optimal and you may be giving up potential charging ability.

[jakubman1]

You don't understand how an MPPT controller works. They will boost the current as they lower the high voltage to the system voltage. All 12 volt panels in parallel isn't the way you want to wire your array. Either go 2s2p or 2s3p or 3s2p.So stay with 4 panels or add 2 more. Not that 5p won't work but it's not optimal and you may be giving up potential charging ability.

Alright NOW i understand. Well then i will not get another panel till i decide to make it 6. I think i can squeeze two more up there so that would be neat to see. Im anchoring down two more today to finish off the 4 i have up there . You guys have been very helpful!

Thank you very much !

Jakub

[Ampster]

Alright NOW i understand. Well then i will not get another panel till i decide to make it 6. I think i can squeeze two more up there so that would be neat to see.

You are fortunate that you chose to use Lithium batteries because you don't have to worry about fully charging your battery pack to keep it healthy. Also the weight advantage in a trailer is important. What are you using for high voltage disconnect (HVD) and low voltage disconnect (LVD) to protect your batteries?
NOTE: Subsequent to this post I looked up that charge controller and see it has good programability for LVD and HVD so I answered my own question.

[jakubman1]

You are fortunate that you chose to use Lithium batteries because you don't have to worry about fully charging your battery pack to keep it healthy. Also the weight advantage in a trailer is important. What are you using for high voltage disconnect (HVD) and low voltage disconnect (LVD) to protect your batteries?
NOTE: Subsequent to this post I looked up that charge controller and see it has good programability for LVD and HVD so I answered my own question.

Hey ! Im going to be also using a 40 amp 12v breaker switch. I think you can see in my photo where i have all my electrical stuff. Its at the bottom right i think. Its the kind you would use for like a trolly motor and what not.

Yes you can build a better battery thats half the price and more powerful than buying from off the shelf. I build them for people upon request.

[Ampster]

Hey ! Im going to be also using a 40 amp 12v breaker switch. I think you can see in my photo where i have all my electrical stuff. Its at the bottom right i think. Its the kind you would use for like a trolly motor and what not.

I don't see any fuse or breaker on the battery to inverter connections but maybe there is one inside the inverter. That one should be around 150Amps depending on the wire size between the inverter and the battery.

Yes you can build a better battery thats half the price and more powerful than buying from off the shelf. I build them for people upon request.

That has been my experience as well. I got my initial Nissan Leaf modules all from one pack. I had used some temporarily in a GEM golf cart and left the switch on and the vampire load took them to zero after a month. I bought some more from a couple of sources and now really have a Frankenpack for my hybrid inverter that runs off 48 volts. That pack is 10P12S and even with that many cells in parallel it starts drifting as they discharge and approach the bottom. As a result I stay away from the bottom and the delta is never more than .05 volts. I could bin them and reassemble the pack but its already at 70% of capacity and I am planning an upgrade in the next few years when I will need more capacity. I keep and eye on it with a BMS and only use the BMS for monitoring because the balancing current is so small it would take weeks to make a difference.

With 4 cells in series most people don't think it is worth having a BMS but I was wondering if you have a convenient way to monitor the balance of the cell groups when that pack is tucked away?

[jakubman1]

Does anyone know how to program this Renogy Rover charge controller correctly so i can get the most out of my solar panels and batteries ? All these Parameters are confusing. It was working just fine i was pulling in 20 amps and then i messed with one of the settings to cut the panels off when the battery reached 15.7v and now its telling me my battery voltage is too high even though it is not according to my volt meter i have. I attached a couple photos. I just want my battery voltage charged up to 15.7v. I want the most i can get from my panels! Please if someone can go through the list with me and ill set each parameter. Thank you for helping me !! A lot of these parameters are confusing and i dont understand

Screenshot_20200330-181416_Renogy BT.jpgScreenshot_20200330-181426_Renogy BT.jpgScreenshot_20200330-181432_Renogy BT.jpg

[jakubman1]

Yes i will be using a BMS. I havent hooked up the breaker switch just yet but its a 300amp resetable.
Heres a link to the BMS i have :https://www.amazon.com/ISDT-Battery-...5607665&sr=8-4
And my reset able fuse https://www.amazon.com/ANJOSHI-20A-3...5607749&sr=8-2