Wiring a Renogy 500A Battery Monitor

[Ray Keen]

I am installing a 500A Battery Monitor I purchased from Renogy and I have a question about wiring the shunt. I have wired a 2AWG cable from the shunt to batteries B- side.
I have a negative busbar with wire from my solar controller going into it, a 2AWG going to the negative side of my 3000 watt inverter, another 2AWG going to the P- side of the shunt from the busbar. I am not sure where to place my negative cable coming from the chassis where it is grounded, the P- on the shunt or the negative busbar or does it matter? Any input or diagrams would be appreciated. Thanks.

[XCMARK]

Originally Posted by Ray Keen

I am installing a 500A Battery Monitor I purchased from Renogy and I have a question about wiring the shunt. I have wired a 2AWG cable from the shunt to batteries B- side.
I have a negative busbar with wire from my solar controller going into it, a 2AWG going to the negative side of my 3000 watt inverter, another 2AWG going to the P- side of the shunt from the busbar. I am not sure where to place my negative cable coming from the chassis where it is grounded, the P- on the shunt or the negative busbar or does it matter? Any input or diagrams would be appreciated. Thanks.

the battery cable size should be 2/0 at a bare min NOT #2 , I hope that is just a typo on your behalf. Back to the question on where the wires go , only the battery connects to the shunt on one side and the other side you can connect your frame ground and all other grounds from your solar charger, inverter ground,battery charger ,hydraulic pump for the jacks and so on. You MUST only have one connection for negative from the battery bank , You should have at least 300 Amp hours of battery's connected to your system to be able to use the inverter to power any larger loads. Basic ohms law 15 amps at 120 volt will be around 10.5X more amps at 12vdc maybe more not know how efficient your inverter is. I am currently installing a complete Victron system with 1300 watts of solar with lots of room to expand the roof solar in the future if I want. What battery are you useing ? Do you have a complete wireing diagram that I can help you more?

[Ray Keen]

Thanks, I will be using 2/0 cables from the shunt to the batteries and will run a short 2.0 cable to the P- side of the shunt to the negative busbar. I will put the negative chassis ground to the P- side of the shunt also. I will run a 2/0 negative cable from the negative busbar to the negative side of the inverter. 1 2/0 cable to batteries from B- side of shunt.
On the positive side I will put a 2/0 cable from the positive busbar to the batteries. then a 2/0 cable from the batteries to a 325A fuse block then into the inverter.
I will be installing 3 Lossigy 12v 200ah lithium ion batteries. Any advice or suggestions?
Ray Keen

[XCMARK]

I would suggest adding some 350 amp disconnect switches one on the battery side of the entire coach , then one ahead of the inverter and one ahead of the solar charger. That way if anything need to be worked on you can take it out and not have live wires laying around . I know my Inverter has a 5 year warrenty but I need to be removed and shipped off to a factory service center. I am installing a midnite solar bypass on the 120/240volt line so I can bypass that also. The battery should have a fuse as close to the battery as possible and you should have a smaller fuse on the inverter, a fuse to the solar charger and a fuse for the going coach side 12 volt panel (every part should have fuse protection for its rating) . You can learn a lot about best practices from this web page and his youtube videos. He works with Victron but other then programing the parts they all should be install with the same disconnects and fuse . I am a electrician with 35+ years of real-world experience and have installed very large-scale solar systems, The web page link below is very good and easy to follow.

https://www.explorist.life/

https://www.youtube.com/playlist?lis...CUwC20DBlyv6s_

https://www.midnitesolar.com/product...tOrder=3&act=p

[Ray Keen]

I do have a 350A disconnect from the coach to the battery positive side and fuse blocks before and after going through solar controller. Also have a fuse block from battery to inverter.
Another question, the cables they sent with the batteries to connect them together are 3awg wires. Will these be large enough for wiring the 3 batteries in parallel? Thanks.
Ray

[XCMARK]

Ray the suggest method of connecting multiple battery's is to put the B+ on one end of the string and the negative on the other far end. by doing this it helps with battery charge and discharge balance. If you didn't have a high draw item like an inverter i would say no problem but with the possibility of pulling 250+ amps from the bank I would suggest getting the same 2/0 and making some jumpers or buying some that are factory crimped if you don't have the correct tool to put the ends on. The #3 wire will have a little effect on where the inverter is getting its power from , I would say you could measure the voltage difference under heavy load with a good digital multimeter. Would I start the system up the the #3 jumpers you bet, but the battery will need a good absorsion cycle after you put the 2/0 in place. I have 1 1/8"x1/4" thick copper bus on the battery bank and the positive on the left battery and the negative on the right-hand battery (currently 5- 100-amp HR battleborn GC2H). Assuming I find the money that will be 8~10 total batteries soon.

[XCMARK]

https://www.pacergroup.net/2-0-awg-b...yABEgK0y_D_BwE

[Ray Keen]

Here is a diagram of the way I was going to wire my batteries. I will use 2/0 cables on all the battery wire.

[XCMARK]

Originally Posted by Ray Keen

Here is a diagram of the way I was going to wire my batteries. I will use 2/0 cables on all the battery wire.

That is correct, just make sure the first time you charge all 3 battery's you let it run at 14.7 volts until you see the battery BMS disconnect the battery at full 100%SOC (state of charge) then you can calibrate the shunt to 100% and you should be good for 6 months on how accurate the meter is. If the main battery disconnect is turned off you will have to repeat the calibration for accurate SOC.

[Ray Keen]

Thanks for all the information. I really do appreciate all you have have done to get me in the right direction on my solar project. If I have anymore questions or concerns I will post them here. Again thanks so much for the advice.
Ray

[Ray Keen]

You had mentioned about putting a fuse as close to the battery as possible. What type and how big of fuse should I use? I assume it would go on the positive side of the battery, correct? I will try to find a picture or diagram to see what you are suggesting? Thanks.
Ray