I must say, pretty impressive. What do you guys think?
Renogy "Smart" 100Ah LiFePO4 Battery Teardown
- Thread starter Will Prowse
- Start date
I must say, pretty impressive. What do you guys think?
D
Deleted member 783
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Why do you suppose they cant be connected in series?
Stupid Monkey
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Seems a nice compact lightweight design 
Steve_S
Offgrid Cabineer, N.E. Ontario, Canada
XT-90 Connectors off the BMS should be the standard IMO ! That is an Excellent way to interface to the BMS compared to soldered on wires.
The BMS, Heat Sink & setup is really nicely done, well thought out.
Pouch cells ! Hmmm They have their pro's & con's but in this type of setup, could be pretty good... 16 pouches though... too bad you could not figure out the specs of each cell (make & model would have been cool)
Bummer they can only go in series ! Hopefully that is just temporary and they'll figure out how to make 24/48+ V
According to PV Mag and a couple of others, 2020 will see a big variety of new "battery packs" ESS/HSS systems with several players getting into it... Competition is good, will drive prices down, features & performance up and put pressure of the others to step up with quality product.
The BMS, Heat Sink & setup is really nicely done, well thought out.
Pouch cells ! Hmmm They have their pro's & con's but in this type of setup, could be pretty good... 16 pouches though... too bad you could not figure out the specs of each cell (make & model would have been cool)
Bummer they can only go in series ! Hopefully that is just temporary and they'll figure out how to make 24/48+ V
According to PV Mag and a couple of others, 2020 will see a big variety of new "battery packs" ESS/HSS systems with several players getting into it... Competition is good, will drive prices down, features & performance up and put pressure of the others to step up with quality product.
D
Deleted member 783
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I know you just mis-typed, but I'd hate to see someone make a couple thousand dollar mistake. They can only go in Parallel.
Steve_S
Offgrid Cabineer, N.E. Ontario, Canada
oops, fixed, was a bit distracted.... was working on #1
Bigbillsd
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Nice! I picked up 4 of the 170ah model. The only issue I have is actually getting Renogy to give me charge settings for my Magnum or Victron controllers. Absorb is 14.4 but everything else like what to do with float is has been non existant. Nothing documented.
Yesterday I got a screen shot of settings from one of their controllers. Sort of a joke for folks that want to make money selling batteries to have no documentation for charging $1500 batteries.
Yesterday I got a screen shot of settings from one of their controllers. Sort of a joke for folks that want to make money selling batteries to have no documentation for charging $1500 batteries.
Steve_S
Offgrid Cabineer, N.E. Ontario, Canada
Just my personal opinion based on years of watching Renogy play with products and their customers, they are Low Hanging fruit and after all I have seen, would not touch anything renogy, even if it was free. I KNOW that may offend or possibly upset some but it is MY Personal Opinion from all that I have seen. The real shame, is they have some good ideas and certainly the capability & ability to do better but they take short cuts and get lazy on "consumer product documentation".
That being said, the Battery Will just reviewed is impressive, especially as it is from Renogy. I did not catch if they sent it to him for review or if it was one he scooped somewhere on his own. IF they sent it, could be a "Pick of the Litter" model. Did they actually make it, or was it a contracted batch from someone else, not likely we will ever know.
That being said, the Battery Will just reviewed is impressive, especially as it is from Renogy. I did not catch if they sent it to him for review or if it was one he scooped somewhere on his own. IF they sent it, could be a "Pick of the Litter" model. Did they actually make it, or was it a contracted batch from someone else, not likely we will ever know.
Defenestrator
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Any idea if they've got a low-temperature shutoff? I'd assume so with the two temp sensors, but assuming is a good way to end up with an expensive doorstop in the winter.
FilterGuy
Solar Engineering Consultant - EG4 and Consumers
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.
Steve_S
Offgrid Cabineer, N.E. Ontario, Canada
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.
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.
FilterGuy
Solar Engineering Consultant - EG4 and Consumers
When I first read the 'separate circuit' theory I thought... No that is just for amperage. However, it is a 100 Amp battery and they had 180 Amps capability. (Actually over 200 when you consider that they are 'machine internal' and are allowed higher amperage. ) So....the idea that there is two separate circuits is a possibility. (I, know, they might be wiring for surge current, but that would be unusual)
I must be missing something about the voltage. Voltage is the potential between two point so the battery only ever 'sees' the voltage between it's two posts. It does not see the voltage of the whole string. How is putting them in series creating higher voltage on one of them?
Bigbillsd
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Seconded! I am getting suspect info from Renogy support. I received a screen shot that shows I should set my Float voltage to 14.4, same as Absorb(boost) and rebulk at 13.2v
I have been under the impression that LiFePo4 batteries should not use the Float setting. So that has me concerned.
I have been under the impression that LiFePo4 batteries should not use the Float setting. So that has me concerned.
I just got an e-mail back from my request for info, and they referred me to the user manual.
Scott
Bigbillsd
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@ScottyH, just keep asking and documenting it with the case numbers so if their lack of support causes a premature failure of the batteries you have the documentation to back your claim. The only spec in that manual is charge voltage 14.4 +-.02% Nothing about about absorb, float or rebulk. Maybe you can ask them for the screen shot of the manual page specifying those battery settings.. I will keep trying to get them to respond with actual answers. -Bill
Agreed there was nothing in the manual. I've sent Sarah at the "online shop" another e-mail.
Scott
electric
Solar Enthusiast
This is true only when all batteries in series are in the ON state. But the moment any one battery BMS goes to OFF state ( any protection event like cell voltage or temperature ) that BMS will "see" combined voltage of the whole pack. @Steve_S is correct that it's all about voltage rating of the FETs. Lower voltage FETs are cheaper and have less resistance, which is more desirable for BMS design. So, its a trade off by design and Renogy decided to focus on 12V applications only with this particular battery. They can still sell a boatload of them even without series connections.
On the other hand, Battleborn uses 80V FETs in their BMS, which allows up to 4 series connections, but their FETs have higher resistance, so they have to put more of them in parallel, so the BMS cost goes up. Its a business/design tradeoff decision, nothing else.
FilterGuy
Solar Engineering Consultant - EG4 and Consumers
Got it. Thank you! This is the first explanation that makes sense to me. Now that you explain it I don't know why I didn't see it earlier...
It is kinda strange they would limit themselves like this. It seems to me the incremental cost of the higher voltage FETs would easily be overcome by the higher sales..... but who knows, maybe they believe the lower price (or higher profit) is worth the loss of the higher voltage market.
It is kinda strange they would limit themselves like this. It seems to me the incremental cost of the higher voltage FETs would easily be overcome by the higher sales..... but who knows, maybe they believe the lower price (or higher profit) is worth the loss of the higher voltage market.
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