Idiot's guide to a self build battery

[Stinsy]

This information might be outdated but jump leads bought in Aldi used to be a cheap source of very high-quality high-current cable…

[Joeboy]

This information might be outdated but jump leads bought in Aldi used to be a cheap source of very high-quality high-current cable…

I will bear that in mind if i need more, just ordered 2mtrs of each red & black 25mm2 cable. Very thoughtful of you.
£1,687- 15 of LF280K (A) batteries incl del, bus bars n bolts
£60.72 - 1 of 15s 5A balance board.
£60 framework and bolts
£20 DC-DC variable 20A buckboard (battery charger)
£38 Amp clamp (AC AND DC capable)
£60 Frankenstein breaker & 2 125A fuses
£26 2 of 2mtr lengths 25mm2 DC cable
£1,954 total

[Oldgreybeard]

This information might be outdated but jump leads bought in Aldi used to be a cheap source of very high-quality high-current cable…

Good tip. I got caught out buying cable some time ago, made the mistake of buying from eBay. When the cable arrived it was suspiciously light for 25mm² and a quick check showed that it wasn't actually copper at all, but copper coated aluminium. No good at all, as the current rating for 25mm² CCA is way lower than that for proper copper wire, around half IIRC.

[Joeboy]

This information might be outdated but jump leads bought in Aldi used to be a cheap source of very high-quality high-current cable…

Good tip. I got caught out buying cable some time ago, made the mistake of buying from eBay. When the cable arrived it was suspiciously light for 25mm² and a quick check showed that it wasn't actually copper at all, but copper coated aluminium. No good at all, as the current rating for 25mm² CCA is way lower than that for proper copper wire, around half IIRC.

Hmmmn, possibly bugger.... the last batch I bought for adding the 2kW inverter was heavy welding cable. I will weigh this batch on its arrival. OGB, thanks for that. I have heard the same story on full reels of say 75mm2 multicore coming in from China for vessel refits/mods, fully certified and inspected yet fake. Its a bad one eh?

For posterity, I bought from this Ebay seller, will report back on the quality once it arrives. We are home Sunday.
https://www.ebay.co.uk/itm/192371086353 ... %7Ciid%3A1

[Joeboy]

I was thinking about a related subject the other day. On these heavy DC cables, would you guys tin the cable end before making off the terminating eye? Was thinking about heat generation within the termination tween individual strands?

[Oldgreybeard]

Hmmmn, possibly bugger.... the last batch I bought for adding the 2kW inverter was heavy welding cable. I will weigh this batch on its arrival. OGB, thanks for that. I have heard the same story on full reels of say 75mm2 multicore coming in from China for vessel refits/mods, fully certified and inspected yet fake. Its a bad one eh?

For posterity, I bought from this Ebay seller, will report back on the quality once it arrives. We are home Sunday.
https://www.ebay.co.uk/itm/192371086353 ... %7Ciid%3A1

The CCA cable I got from eBay originated in China. No indication from the seller that this was where the crappy stuff came from, and not worth sending it back as the postage would have cost a fair bit. I still have it sat here and apart from being light it also flexes a lot more easily than copper.

I was thinking about a related subject the other day. On these heavy DC cables, would you guys tin the cable end before making off the terminating eye? Was thinking about heat generation within the termination tween individual strands?

Best not to tin the ends, my experience with doing this has resulted in cables breaking when subject to any vibration or movement, as it creates a stress raiser where the tinning ends. A decent crimp will literally squeeze the strands together so tightly they will be in intimate contact at the molecular level, so there won't be any issues with high resistance joints.

[Joeboy]

1,093 grammes at 4mtr length. 273.5 grammes per mtr, seems to be good.

[Joeboy]

Even just working out how to load the fuses left me feeling like a daftie!!

[Joeboy]

For Caesium on his hols, a fix! Stinsy's active cell balancer arrived and is now in storage.



SWMBO very kindly donated an old tabletop which will be the mounting surface for the wall mounted battery assembly.

[Andy]

Even just working out how to load the fuses left me feeling like a daftie!!

I guess you've probably worked it out by now. For others this guy and his wife have done a diy install of an offgrid Victron setup using Pylontech batteries. They have loads of videos of all the steps. This one is for the battery fuses which look similar to yours -> The Off Grid Family