Renogy "Smart" 100Ah LiFePO4 Battery Teardown

[backyardshane]

Does anyone know what the old renogy battery looks like inside?

i know they are 26650's 4s30p but i would love to see a teardown on one

 

[ScottyH]

This was my reply for Renogy

"Thanks for your email, please note that the charging profile of lithium battery is quite different from the traditional lead acid batteries, only need to set the bulk charging voltage,

When you use a charge controller to charge Renogy lithium battery, please first confirm the charge controller can charge lithium batteries, choose lithium as battery type and then set the bulk charging voltage, this will do."

Scott

 

[Lumo]

Would anyone have the correct settings for the Victron BMV712 with Renogy 100Ah battery? I have contacted Renogy several times requesting this info and they have responded with a link to the manual..

 

[El Jack]

The reason there is 4 wires is to carry the load, they can't put say 1/0 cable in there and attach that to the BMS, so instead they us "pairs" that allow for the capacity without the single larger wire in there. This is not unusual or strange, it is a common way to ensure the wire capacity is there to handle the amperage going through it.

The internal BMS is designed for 12 Volts not 24,36/48 , setting batteries in series take the voltage up and will fry the BMS because it's over voltage. This is largely due to how the boards handle the voltage, cut offs etc. Some BMS' can handle various voltages allowing for Series & Parallel but these are more costly and complicated typically with external handling of the throughput power. BMS' which use FETS are limited by FETS and typically not seen on a BMS rated higher than 150A and are limited to specific voltage ranges, above 150A the BMS' will use either electronic or electro-mech Relays due to the power running through them and are usually capable of different voltages as a result.

This is quite a generalised & basic overview, hope It helps.

Thanks @Steve_S as usual a repertoire of information.

And I'm with you, Renogy strike me as a 'rebrand' company. Such a catalog of hit-or-miss products, I prefer more reliable vendors.

 

[orangeminnie]

Interesting reading:

Pouch Cell - Small but not Trouble Free – Battery University

Learn about battery technology, battery maintenance and battery life at Battery University

batteryuniversity.com

I short, pouch cells might be the least reliable, and most picky about temperature and humidity, of any of the 3 common form factors.

 

[Justin Laureltec]

Would anyone have the correct settings for the Victron BMV712 with Renogy 100Ah battery? I have contacted Renogy several times requesting this info and they have responded with a link to the manual..

@Lumo that's a little tricky given that Renogy doesn't know what they're selling at any given time... but assuming for the sake of simplicity that a Renogy LFP battery will have basically similar performance characteristics as a reputable-brand LFP battery, you can use the following settings and figure you'll at least be in the ballpark:
Capacity: xxxAh (100 if you only have the one battery)
Charged Voltage: 14.0v
Tail Current: 2%
Peukert Exponent: 1.04%
Charge efficiency: 99%
Low SOC relay (discharge floor): 20%

 

[Blake2230`]

@Will Prowse or others, can you safely buy 2 of these batteries use them in parallel and add more in parallel later?

 

[Kesa32]

Yes apparently it's quite a few you can parallel , the manual for the monitor says it can ONLY monitor 9 individual smart batteries in parallel , after that it can't tell you info on the tenth etc

 

[Bigbillsd]

@Will Prowse or others, can you safely buy 2 of these batteries use them in parallel and add more in parallel later?

Yes you can, I have 4 of the 170AH in Parallel.

 

[SOK-MIN]

In the YouTube comments I found this:

Does anyone know why they say not to use them in series? "

"At minute 1:36 you will see 4 black wires. 2 for charging and 2 for discharging, that is the reason this bms is not able to connect in series. If you have an external bms that control the charge/discharge of all cell then you can connect all cells in series. "

"The bms charge or discharge at different times. Never at the same time. If it is in series and one of the battery pack is fully charged it will change to discharge state and cut the power to others pack that may need more charge. The same situation occurs when discharging. If one pack is too low it will change to charging state while the others packs still with charge level higher than the others. "

I don't know if that makes any sense or not, but there may be a thread of truth in there someplace.

@Will Prowse Did you happen to notice if the two pares actually went to different circuits on the board? I can't tell from the video.

em, if you want to connect the battery in series, it depend on the MOS voltage, for example, some of the MOS Max voltage is 20V, if you connect 2 batteries in series, the voltage would up to about 29.2V or 30V, the MOS would be burnt.

 

[Blake2230`]

Yes apparently it's quite a few you can parallel , the manual for the monitor says it can ONLY monitor 9 individual smart batteries in parallel , after that it can't tell you info on the tenth etc

Sorry to be clear the question was more in reference to adding more batteries later.

 

[Blake2230`]

@Will Prowse or others, can you safely buy 2 of these batteries use them in parallel and add more in parallel later?

Sorry this question was more in reference to the efficacy of adding more batteries later.

 

[wireright]

I must say, pretty impressive. What do you guys think?

I would really like to see you test what would happen if you paralleled one of these with a few other lithium battery brands that have the same amp hours. Maybe another manufacturer with bluetooth? I see they don't suggest it but I thought you suggested it would be ok. Lots of people would just add another battery to their rv if that was an option. I'm just hesitant to do it myself for a test.

 

[Rich m]

Will says there is good tech support? I have found it terrible!