Thank you for this great upgrade, Paul!

Any issues with the aluminium oxide layer between the battery and busbar? over time it should hold up?

yeah he reminds me abit of electricboom.

Hi Dan, that is exactly correct what you're saying and I will show this in my future videos again. All is fine as long as you stay in the flat part of the curve, right. The busbars have greatly approved the situation now.

Thank you.

That will definitely work, Gaz!

@@OffGridGarageAustralia It's amazing how far you have come in this time Andy. Thanks mate

Recently purchased a 2012 Leaf battery pack to upgrade my bulky Lifepo4 pack on my ride on mower conversion. Not something you want to be near if you can't easily get away from the worst-case event. I'll be connecting my ancient Lifepo4 200a cells to my new Victron Easy solar which should arrive today. Andy's journey is a real gift for people starting out in off grid projects.

@@andrewradford3953 especially for a wheelchair user. I did take a lot of precautions and finally found a 24V 6S BMS's (One for each set charge only) I had two sets of three cells in series and then running both sets in parallel in 24 V configuration. Then I used a victron smart battery protect for the high amperage controlled by the BMS with added low temperature protection , Low-voltage etc. Sorry this is off topic I can answer more questions on my page.

@@andrewradford3953 I do like the Nissan cells I will probably repurpose mine for a DIY power wall in a metal enclosure. I have approximately 3KW in a wheelchair and a standby 1.5 KW backpack power pack as we call it basically just a battery in a backpack with an Anderson plug

Hahaha, thanks Joe. Can't wait to see your setup when you get 'everything right' 🧐

Zwei meiner Vorbilder in einem Text... Ihr seit großartig!!!

I have now polished and used carbon grease while polishing my terminals and busbars. Original busbars. Problem fixed. Stays in balance perfectly now.

Yep, that will definitely do the trick. A simple Al flat bar and cut into pieces.

Low frequency inverters are much, much better at surge loads than high frequency inverter.

They seem to have fixed the issue.

I may have to contact Paul 🤔 Andy around 15:20 ish the closing speech started lol it might be in the wrong place. My movie maker glitches like that sometimes too hehe just saying but you may have planned it to. Catch you soon brother ✌

Thanks 👍

Copper busbars are more conductive and more resistant to corrosion than Al.

@@neliosamch3195 Just by graduated and calibrated eyeball, the cross sectional area of the new bars is about double the previous which will compensate for the 60% conductivity factor of Aluminium, provided certified joint paste is used. Personally I will use the copper bars that come with the cells unless there is a fit up problem. I will however go to a lot of trouble with workmanship and material choice.

@@mikenewman4078 Right, but do we have any research that indicate that we need more than 20A bridge between cells to justify such humongous busbar?

Pardon my ignorance, but what do you use to do the individual cell tests? Something to measure the battery impedance?

@@Swinopolis Matt, individual cells can be charged, voltage checked, ohms of resistance measured, and load tests with amp/hours measured in load for a period of time until desired voltage is reached. Matt, I'm a newbie but that's what I guess.

Thanks!

The battery performs well, no question. I still want to understand a few things so I keep testing different things. Swapping the two batteries is on my list.

@@OffGridGarageAustralia I would bet the usual china issue of different cell sources they had sold in the beginning or even used cells.

I think the mulcher don‘t start as quick because the Inverter has a load sense that starts providing more power only if it is needet. That‘s how my Inverter (Studer) works to save Energy.

Yes, this test is on my list... but wait for the whole capacity test i the next video.

It should be 0mV from the terminal to bus bar. If I cannot measure it with my voltmeter, it's below 1mV and considered 'good' for me.

Yes, we're almost there!

Yes, you can do that. But the BMS wires are not the problem as I checked all voltages and compared with the ones the BMS shows.

Any time

No, I still haven't done this yet.

It's the cells 6, 7 and 8 which are lower. But are they really lower or just unbalanced. I'll do the test in the next video...

It should not make a difference though as the balance leads only measure voltage.

@@OffGridGarageAustralia but you see voltage difference on your cells measured by the balance leads. So a small resistance difference can cause that it's only mV

@@villacarinaapartments I only see that because I'm pulling full load so the current going from the terminal to the bus bar causes the voltage drop. But I cannot measure that fro the stud to the ring lug of the balance leads. There is no current going from the terminal though the stud to the ring terminal and washer to the busbar. It all goes from the terminal to the busbar.

@@OffGridGarageAustralia correct but the voltage you see on the bms app come from the balance leads witch are not direct to the cells but have to go thru the washer first. And that's stainless steel. So more resistance than if it was directly on the aluminium bus bar.

Nope, checked them all several times and compared with my 4 digit voltmeter. They all seem to be the same and consistent.

Josh, That is no surprise, Nickel oxide is a pain. You can't see it because it is transparent, it is good on stainless steel but not so good on electrical connections, Duetch connectors are a pain that way.

Yes, click on the link in the descriptions and you can play with the calculator.

No, not yet. they seem to be very good though. I may end up threading them into the busbars anyway at some stage

@@OffGridGarageAustralia imo a good crimp does not need any solder added to improve conductivity.

Yep, absolutely and I haven't fully charged the battery for a while.

The problem is not the busbars - full stop. The busbars and the connections between the cells is virtually identical. It's easy for busbars to be manufactured within very tight specifications. And, countless millions of busbars just like these are in service all over the planet and are not the source of any kind of problems in their installations. On the other hand, the battery cells themselves are not manufactured to such tight specifications and there can be significant variations between them in the manufacturing process. This is why they must be matched with each other and balanced prior to using them together in a battery pack. When battery manufacturers create battery packs, they have thousands of cells from which to choose. They select those cells that are closely matched to each other in capacity, and not just voltage. And, they disqualify cells that are not matched or do not meet the capacity specifications of the cell manufacturer. Those cells end up on the market as "B" grade cells. Consumer hobbyists then acquire these cells and put together their own battery packs. Unfortunately, they can't be so discerning with the cells and are pretty much stuck with the cells they purchased. If they bought sixteen cells and one of them is out of tolerance in terms of capacity, their choices are simple - either accept that their pack will be degraded in capacity or purchase a replacement and hope it will be within tolerance. I suspect what is happening here is that one of the cells is either out of balance or mismatched to the other cells in terms of capacity. No amount of polishing busbars or using conductive paste or rearranging the cells is going to correct that problem. My suggestion would be for him to purchase at least four more cells and hope one of them will be closer in tolerance to the others in his pack of sixteen. Then, he can cobble together a 4s1p pack that will, of course, be mismatched and of degraded capacity. But, his main pack can still be serviceable.

@@richardowens9061 Its for the reasons you mention I purchased 4 extra cells.

@@richardowens9061 I've done a full capacity test coming in the next video...

How do you compare the effect of different washers? I think we're getting into territory which is far beyond any DIY. A normal spring washer does the trick, I guess.

@@OffGridGarageAustralia A spring washer is designed to keep tension on the join, a copper washer is designed to maximise the contact area , which is what you were attempting to do with the copper paste, which would be more suited for heat transfer than electrical conductivity.

I think he did just that a couple of videos ago , but still dosent seem to be helping. Ofcourse now he has new busbars so maybe can be some diffrence. I think the provider sent with a b-grade cell with the a-grade ones.

I did a full discharge test. Wait for the next video.

Ill buy some chili nuts and some beer for next episode.

A test of that is still on my list...

You mean the battery box or the electrical cabinet?

The cells don't move or flex. I checked the surface area when empty or fully charged, there is no difference.

Video coming soon ;)

I keep an eye on the voltage. Battery is at 50% only and cloudy weather so no problem. But you're absolutely right.

4Nm and no Loctite.

Yes

Yes you can, but you have more connections and more resistance as you need to crimp all these short cables to ring lugs.

I've got the Noalox paste now for the next installation.

Thanks Ian, I have the 8-cell CellMon but I don't think it can actually balance (even it says so). The BMS does actually read all voltages accurately but just takes a while to balance these large capacity cells. It may take several cycles until I will see a progress with this.

Thanks for the reply. The thing I LOVE about the BattGo is that you can manually begin a balance at any state of charge - yes it takes a while with larger battery packs, but still an amazing bit of kit for the price.

I cleaned them with alcohol and put them together immediately. I also moved them back and forward a few times to rub off any oxidation. So far all seems to be working. I have ordered some different anti oxidant grease just in case I have issues again but won't use it right away.

That should make for good test, thanks for sharing your experiences with your build!

@@OffGridGarageAustralia "Noalox" anti-oxidant compound is made specifically for aluminum to aluminum connections.

Also your stainless steel fasteners may react with the aluminum over time something to keep an eye on...

They just sense the voltage so no current is flowing through these cables (unless the BMS balances the cell). Resistance does not matter therefore.

Many have suggested that. What is the difference though? Should the balance cables not be as close to the positives as possible? Under any load, you will have a voltage drop to the middle of the bus bar already, right. So your measurement will be more off the higher the current is. I don't see the advantage of doing it. It's this just a trend right now?

@@OffGridGarageAustralia No, no trend or anything. Was just thinking of a way to rule out connection shinanagins for your voltage drop issue but maybe switching to aluminum bus bars fixed it for good.👍

Yeah, know what you mean. Gives you a bit better control when tightening the nuts not having so much stuff to worry about. I'll keep thinking about it 😉

He did show at a couple of points where he'd buffed off a bit of the nickel on the outside and it def looked like Cu underneath.

When I polished the busbars, they showed pure copper underneath.

The washers are made of stainless as well, but they are not conducting any power, just pushing down on the busbar. I've checked all balance leads voltages with a voltmeter and they match the ones the BMS shows.

@@OffGridGarageAustralia if you read the low value in the app when applying load on the cell, is the cell the same voltage when measured with your multimeter? If so then probably the difference in chemicals in the cells might give this effect. If the multimeter shows a different value can it be inductance on the wire because of load applied (just a guess). Thanks for all the testing and checking this all on your journey together with the community!

Checked all cells with the voltmeter. They do match the reading of the BMS.

Have a look in the video description. All info is there and on my website: off-grid-garage.com/batteries/

@@OffGridGarageAustralia Herzlichen Dank!

Lyfan Deth. Aluminium jointing paste is not grease. Its job is to cut through the oxide layer and prevent it from reforming. The information is available from Utilux or Dulmison. Jointing Aluminium conductors can be a real pain and lead to spectacular failures if any short cuts are taken. When lugs or links are applied to aluminium cables, the lug comes pre-filled with jointing paste and sealed. The cable is cleaned and rammed home. The entire length of the barrel is then crimped in steps at 23 tonnes ensuring the paste is trapped in the joint.

Cool beans

These are SLA batteries (6 cells internal) and cannot be compared with lithium, if you have more than two batteries in series it may be wise to use a Victron SLA battery balancer.

Surely a voltage drop at the terminals is a problem for any chemistry? I've seen a few videos with cell balancers I think the Victron one would need 3 to do a 48v battery and additional link's to interconnect the two strings of batteries? I've also seen one that's 48v available from Amazon. Some information says it's not necessary at all. My system is two 3kva easy solar units essentially two 3kva multiplus and two 150/70 mppts I've disconnected one colour control and one set of RCD/mcb's and 12 x 300w panels.

@@551moley You would indeed need your three "Victron battery balancers" for a 48Volt set-up, it is possible without, the same for lithium cells, but risk or safety is always a choice ..

Watch the video until the end ;)