Thanks everyone for your replies / suggestions, they are very much appreciated.
DIY Battery Is Alive !!
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Hi @johnb2713
I am joining a bit late. Sorry.
Congratulations on your achievement. I know it has taken you a long time of research, many head hacks and perseverance.
But now you have it!! Well done
So what's the next project
I am joining a bit late. Sorry.
Congratulations on your achievement. I know it has taken you a long time of research, many head hacks and perseverance.
But now you have it!! Well done
So what's the next project
I think this parameter for high alarm can be changed. I’m going to quote again, sorry:The latter I can just about cope with
I do enjoy tracking faults down and resolving issues.
Seplos has 3.5v as alarm high and 2.9v as alarm low and you cant adjust them, they're locked (well they are until Seplos tell me how to get into them).
“
If you have a seplos BMS you can use Battery Monitor from seplos, if you are connected you can change many options.
Look at the link:
https://drive.google.com/drive/folders/10pxgNLHovcDZRVGrCZsSkfecBrRw-AdW
there you can read in PDF for your BMS. If you have a 100Ah BMS with Can o 485, you find all there.
password is Admin and key also Admin
You find all options in Upload parameter.”
source: https://powerforum.co.za/topic/14433-diy-280ah-battery-for-imeon-36-inverter-with-seplos-bms/
On page 12 of the Battery Monitor manual it clearly shows that this high level alarm can be change from the default 3500mV. You must log in as Admin as a safety precaution.
Hope this helps and do let us know.
Other parameters I can change and it allows it logged in as admin, the high level alarm it doesnt allow the change.
I have requested help from Seplos but not heard back yet.
Thanks for your help.
After todays charge things seem to have improved in terms of balance.
Yesterday there was 21mV between highest and lowest, today only 3 mV, I assume top balance not really needed now?
The only other issue is the 'Rated Capacity 150.00 Ah' The capacity is actually 280 Ah and it's not an accessible figure. On the charge overninght the BMS actuall stopped the chage and I've disbled the low voltage cut off on the inverter in the hope I can run it down to low voltage cut off in the hope this will trigger the Seplos calibration points?
Yesterday there was 21mV between highest and lowest, today only 3 mV, I assume top balance not really needed now?
The only other issue is the 'Rated Capacity 150.00 Ah' The capacity is actually 280 Ah and it's not an accessible figure. On the charge overninght the BMS actuall stopped the chage and I've disbled the low voltage cut off on the inverter in the hope I can run it down to low voltage cut off in the hope this will trigger the Seplos calibration points?
ollied1981
New member
There's a bug with the Seplos software where clicking the button to change just one parameter doesn't work and says failed, but if you click set all it will work. However, when you click set all it will obviously change all the parameters to what you see on the PC so make sure the numbers are what you want! I've just built a similar system with a Seplos, 16 X 228ah CATL cells and a Sofar ME3000SP.
Oliver
Oliver
Can I download all of the current parameters and display them in the upload window so in the worst case I just upload back what it's already got?
I'm also trying to find a way to stop the charging at 90%, not easy with the Victron (amazingly), I wonder if I can get Seplos to open the charging relay at 90%?
Thanks for the info.
ollied1981
New member
So far as I can tell when you click the upload parameters button at the top it actually downloads the currently stored parameters first and this is what you see in the "parameter manage" panel, with the one exception of no.59 SoC which always seems to default to 50Ah. So if you want to keep the current SoC percentage you'd need to set this to whatever the current remaining capacity in Ah is.
There's a save as button in the parameter manage window you can use to save the current values. I did this before I changed anything.
I'm not sure if you can get the Seplos to do anything with a 90% SoC, there only seems to actions for low SoC with 78 and 79 for remaining capacity alarm and protection.
There's a save as button in the parameter manage window you can use to save the current values. I did this before I changed anything.
I'm not sure if you can get the Seplos to do anything with a 90% SoC, there only seems to actions for low SoC with 78 and 79 for remaining capacity alarm and protection.
I read that changing some parameters requires one to hit enter after entering the button and click download. Hopefully this works as an alternative to having to set them all.
May I ask what swayed you in the direction of the CATL cells please? Was it price, performance etc?
ollied1981
New member
Originally I'd planned to use the LF280K, but when I ordered at the beginning of November the GBP USD rate was truly dismal so decided to get the next size down as that's still enough kWh for my needs. Docan Power had the Eve and CATL 230Ah size for about the same price and since CATL makes about half the lifepo4 in the world and supply several EV makers I thought they probably know what they're doing. They were about £1625 total cost delivered and took about 6 weeks via sea freight.
rabnudj
Member
I'm honestly really considering copying your self made bettery, looks to be an excellent and simple solution.
I've a few questions please ...
1. I'm concerned about MCS certification and house insurance with a "home made stuff" what is your experience with this side of things?
2. The BMS you have used uses Passive balancing, why did you go for this inferior type?
3. Did you use grade A or grade B cells? If you used grade B, what was your experience?
TIA.
I've a few questions please ...
1. I'm concerned about MCS certification and house insurance with a "home made stuff" what is your experience with this side of things?
2. The BMS you have used uses Passive balancing, why did you go for this inferior type?
3. Did you use grade A or grade B cells? If you used grade B, what was your experience?
TIA.
I just told insurance company that I’ve added an additional 14 kWh battery AC coupled into the system, I added all of the solar PV and batteries onto my house policy.
Yes it does but it’s the one that would readily talk to the inverter. The batteries are staying within 10mV of each other so I’m happy with that.
Grade A
@johnb2713
A good two weeks with your homemade batteries, how are things going?
A good two weeks with your homemade batteries, how are things going?
All good thanks, everything settled I just forget it now. Since switch on, we havent used any Peak power at all, everything is on the 7.5p from GO. I had a couple of setup issues that were easily resolved, I couldnt understand why my battery charging didnt start until 02:30 and then only charge to 80-90%. It was a grid current limit set in the inverter, it was seeing we were taking 50A and therefore wouldn't charge the battery until demand had dropped. I found the setting but I could go higher than 50 amps. The solution in the confic file was to tick the option for an external CT and off it went. I managed to max out my grid supply during the night, ran at 98 amps for 30 minutes.
I am somewhat surprised how well its all running, first time!
I am somewhat surprised how well its all running, first time!
MCS only applies if you want to take advantage of certain energy tariffs, or you have a registered set of solar panels - don't alter that and it's nothing to do with them. The only legal bit is notifying your DNO that you have a set of batteries. Ideally notify them in advance of installing.
Hi John, sorry for late input. I am considering a battery storage from cheap night rate electricity, could you or any one else please let me know 2 things really.
1) do you require a separate TT earthing system for the battery storage?
2) how does/ the system change between battery and grid safely?
any pointers to answer these questions would be helpful
No problem
No seperate earthing in my case.
The system doesnt change between battery and grid, theyre both connected at the same time. The inverter synchronises to the grid supply and if it sees current flowing to property it increases it's output voltage, if it sees power being exported to the grid it will reduce it's voltage. So as you can see it never disconnects the grid supply and switch its own supply on (This is grid tied mode) you run then other modes i.e. grid into the inverter and from the inverter to the house.
This is different to Island mode, which is where I am getting confused, if I may ask what I am trying to achieve is cheaper electric bills from charging the batteries on my cheap overnight electric I get 4 hours at a greatly reduced rate over night, what is the best type of system if there is such a thing?
Ac battery system, which is grid tied inverter, all of which have a UPS function for power failures, but unless that happens to you on a regular basis, I would not be over worried about that. On the other hand, if you have a lot of freezers, then that could be useful to you, or you are concerned about the threatened possible power outages.
Hi John where did you purchase your BMS from and which setup have you used model wise cheers
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