Hi everyone,
I fixed up the first of five batteries today and thought that a picture of the fix tells more than a thousand words ever could:
As you can see, the 6 BMS wires now feed into a 300A bus bar all with M8 bolts which is attached to the battery lid. There are now only 2x BMS cables to...
Hi labeeman,
The batteries are only three years old and out of warranty. I'm pretty sure that you could get high amp BMS circuits three years ago. If someone had done a tear down video of one of these batteries beforehand, I'd never have purchased the things (knowing what I know now). The tear...
As a bit of an update, the four batteries survived the modification process and the terminals, lugs and cables and are now running cool.
Those are 50mm2 cables linking the batteries and the markings on the green case are reflections. It ain't pretty, but it works.
Hi everyone,
I'm in the process of purchasing a spare 48V off grid inverter of around 3000W to 5000W continuous output. I currently have a 48V Latronics 5000W inverter and it runs flawlessly in all conditions and has done so for years. Nothing lasts forever though. For those who are unaware...
Hi Bud,
Thanks for your thoughts with this issue. The 6x BMS were glued to the cells, and the cells were wrapped in some sort of blue clear-ish plastic. I was unable to determine whether a further layer of insulating material had been placed between the plastic and the underside of the BMS. My...
Hi upnorth,
Respect! 63' north with solar is an impressive achievement. I hear you about the low winter solar consumption of the inverter, and my Latronics unit will use a constant 0.6A, but also has a standby mode I choose not to use. Many thanks for sharing your solution to this predicament...
Hi everyone,
Newbie here, but have been off grid since 2009. As part of the regular checks of the system I noticed that the battery terminals for my Pro Power 12V 306Ah LiFePO4 batteries were running hot - hot enough that you would burn your fingers if you left them there for a few minutes. Four...
Hi everyone!
I've been using off grid solar since 2007, and have powered the house using the technology since 2009.
Recently I've been have been considering all aspects of the 48V system after repairs to the LiFePO4 batteries became necessary. I posted about that subject elsewhere and you can...
Hi Jay,
Yeah, no worries at all mate. 100A is something which requires, err, a persons full attention.
Look forward to hearing about your experience with the temperatures on those terminals. It's something I've been wondering about.
Still balancing the batteries today. Taking off 10Ah at a time...
Hi everyone,
Newbie here, however I've been off grid for more than a dozen years. Three years ago I replaced the ageing 48V bank of 600Ah sealed gel lead acid 2V batteries with some LiFePO4 batteries. 4x 12V 300Ah (apparently 306Ah) Pro Power LiFePO4 batteries to be precise. They've worked...
Hi upnorth,
Respect. A valid point too, you can never be too sure with electronic components and their longevity.
Thanks for mentioning the transistors too. I'll follow your advice and nab the replacement components.
Cheers
Chris
Hi Bud,
Yes, not good. Fortunately the batteries won't be moved around at all, although removing the lid did require a bit of force.
Your comment got me wondering, and looking closely at the image it appears that the manufacturer used blobs of silicone as a glue between the BMS and the cells...
Hi Nobody,
My thinking exactly now. Have a spare inverter. Have spare parts. Avoids all manner of unpleasantness with no power.
For your interest, I also run a smaller 24V off grid PV system for my work shed, so worst case scenario, urgent repairs can be done there.
Cheers
Chris
Hi Jay. Thanks. Yeah, opening the case was an interesting exercise and I was considering doing a YouTube how-to clip showing how I did that step by step (with disclaimers, lot's of disclaimers - don't do this at home kids!) Do you have any thoughts about that?
Those were the exact batteries I...
Exactly. Until you have regular charge going into the battery bank it'll be hard to determine what their self discharge rates are between all the different cells. It might surprise you though, especially if they've all come from the same source and were manufactured around the same time. I'd be...
Hi! Yeah, my experience with LiFePO4 batteries is that they seem to work just fine when connecting up in parallel two different brands and differing capacities as long as they are the same overall voltage (a 48V system in my case). Like LakeHouse replied, I ensured that they were mostly charged...
Hi Jay. How did you go?
As an update, finished adding the bus bars to the three other 12V batteries last night, and now I'm going to try balancing them all during the next week or two, whilst using them at the same time. Should be interesting! After the work involving the battery fix and...
Hi SparkyJJO. Mate, it's not just you, I didn't expect to find that arrangement inside the battery either. I'm coming around to the point of view that the batteries either need clear cases so that you can see what's inside, or have easily removable lids for inspection. The tear down videos from...