OK Great now I understandSorry, spoke to quickly.
The next bottleneck will be the cells themselves.
The limit will be ~140 amps(.5c).
140 amps * 24 volts low cutoff * .85 conversion factor = 2,856.00 ac watts.
This would allow a 3000 watt inverter.
Sorry, spoke to quickly.
The next bottleneck will be the cells themselves.
The limit will be ~140 amps(.5c).
140 amps * 24 volts low cutoff * .85 conversion factor = 2,856.00 ac watts.
This would allow a 3000 watt inverter.
I don't have a super good recommend for a 200 amp 8s BMSWhat 200A BMS do you recommend for a 8S 24V LiPo ?
Its a general estimate of the conversion efficiency of a generic inverter.Sorry .....
one last question just so I understand your math
Where is the .85 conversion factor coming from?
This one is my fave https://www.donrowe.com/samlex-evo-2224-pure-sine-inverter-charger-p/evo-2224.htmThank you for saying that
Do you have a recommendation for an Inverter/charger ?
3000w Victron?
3000w Aims?
or something else
regards, Rick
Is this statement saying that- it's not actually the amperage rating of the installed bms that matters (for the inverter size or otherwise) if the settings for the battery (programed into the bms) need to be at a lower amperage than the bms itself?Those 280ah cells should not be discharged at a continuous rate of >.5c(140 amps) as they get hotter inside.
So the bms is only really a small bottleneck at 120 amps.
The BMS will be the gating factor.Is this statement saying that- it's not actually the amperage rating of the installed bms that matters (for the inverter size or otherwise) if the settings for the battery (programed into the bms) need to be at a lower amperage than the bms itself?
I have the same question as the author here, except my system is 304ah 12v battery (4 cells). I have an overkill solar 120a 4s bms and a 2200 watt inverter from Giandel. I started to scratch my head when I saw that Will said a 1500 watt inverter would work for that size of bms. But maybe there is more to it than meets the eye? I didn't quite follow this thread well enough since it was 24v and not 12v. But maybe the info is here for me somewhere? Thanks yallz
Alright ya, I have a question or two. The needing another set of a 304ah battery.. You mean all 4 cells of the 304ah type right? Or are you saying that the 4 cells I have would be split up and put in parallel?The BMS will be the gating factor.
.5c for 304ah cells is 152 amps but the BMS is only rated 120 amps continuous.
2200 ac watts / .85 conversion factor / 10 volts low cutoff = 258.823529412 service amps
258.823529412 service amps / .8 fuse headroom = 323.529411765 fault amps
That means 3/0 awg wire with a 350 amp fuse with breaking capacity of at least 10000 amps.
It also means you need 2 sets of 304 ah hour batteries in parralel each with a bms rated for 150 amps or better.
If any of this is not clear please ask specific questions and I will be glad to answer.
4 cells makes 1 12 volt battery.Alright ya, I have a question or two. The needing another set of a 304ah battery.. You mean all 4 cells of the 304ah type right? Or are you saying that the 4 cells I have would be split up and put in parallel?
120 continous amps * 10 volts low cutoff *.85 conversion factor = 1020 ac wattsThis may be teaching me a thing or two, but to be clear- I only plan on having the 4 cells 304ah pack used in my van, which is sounding a fairly overdone for my purposes already (a 12v fridge, a little PS4 gaming here and there, a small projector, maybe a diesel heater in the future).
Would I need to aim for a smaller inverter anyway for my simple setup?
Capacity is measure in amps or time or watts over time.What I'm saying is, I have more than enough capacity with this pack as it is.
Daly BMSs have very load capacity to balance your batteries.My heads already starting to turn towards a Daly however, I know you aren't a big fan of them.
See above ^Or... What size inverter would be more kosher with my setup you think?
What vendor did you get your cells from?If any more info is needed, I can provide that. Thanks
I'm glad to help.That wire sizing was helpful to see too btw. I've been piecing my system together for almost a drawn out year now, and it can be helpful to see info about specific wire sizes and fuses.
This may be teaching me a thing or two, but to be clear- I only plan on having the 4 cells 304ah pack used in my van, which is sounding a fairly overdone for my purposes already (a 12v fridge, a little PS4 gaming here and there, a small projector, maybe a diesel heater in the future).
Would I need to aim for a smaller inverter anyway for my simple setup? What I'm saying is, I have more than enough capacity with this pack as it is.
So mine are from Amy with Docan Power. They are eve cells, grade A. Right now everything is sitting at my sister's place while I plan to tweak things into shape but the system will go into a cargo van under my bed. And I'm planning to build a custom box for it that controls the temp with a fan and some heating pads too. In this video (a short segment)4 cells makes 1 12 volt battery.
You need 4 more to make another battery.
If you go with another 120 amp bms your aggregate continous amperage would be 240 amps which is slightly less than the service amps I calculated.
120 continous amps * 10 volts low cutoff *.85 conversion factor = 1020 ac watts
You bms can handle a 1000 watt inverter
Capacity is measure in amps or time or watts over time.
The continuous rating is measure in c rate or watts or amps.
Daly BMSs have very load capacity to balance your batteries.
Most of the cells that folks purchase here would not stay balanced with a Daly BMS.
That means adding an active balancer which is a whole other kettle of fish.
See above ^
What vendor did you get your cells from?
I'm glad to help.
Is your setup mobile or stationary?
Docan supplies good cells but they are very lilkely not grade A.So mine are from Amy with Docan Power. They are eve cells, grade A.
I showed my math.Right now everything is sitting at my sister's place while I plan to tweak things into shape but the system will go into a cargo van under my bed. And I'm planning to build a custom box for it that controls the temp with a fan and some heating pads too. In this video (a short segment)At 11:14 he states that this exact bms can handle 1500 watts from a 12v inverter, like the one he is testing with.
I gave you my advice in good faith.I've always heard that you want to go for the largest inverter that you can afford/will work for your system.
Please share the math.I don't really have a problem emailing these companies though to swap this inverter out for a smaller one and the bms out for something more suitable too. But it sounds to me like the bms may just be fine. He also multiples by a different number to get that result.
In that video I shared, he's multiplying the 120a from the bms to "12.8 nominal". I suppose that # is just the voltage of the pack?Docan supplies good cells but they are very lilkely not grade A.
Grade A means automotive grade and they come with test reports from the manufacturer.
I showed my math.
I gave you my advice in good faith.
Do with it as you will.
Please share the math.