VoltX Battery question answered From my first series and how to parallel cheep lithium batteries

In this video I answer some of your most common questions that were asked about these batteries when I did the review.
I try to answer questions about how to parallel these batteries safely, whether top balancing makes any difference in AH capacity and if a active balancer makes a difference.
Since doing this video I’ve done some more testing and the active balances really do make a difference but having the ability to turn them off when the batteries are not in use i.e. in storage Is a good thing to have as the active balancer will chase voltage and you’ll end up with cell in balance. If you are constantly discharging and charging the battery to no more than 80% of death of discharge you can leave the balancer on all the time and this will help keep cells balanced. I stuffed up the video I meant to say passive balancing not active balancing for the BMS in these batteries.
Please remember I’m not making any money out of these films I’m doing it for fun and hopefully to help others.

[@DoctorVernAcula]

Fantastic video, thanks Phil! I've had two of these running in parallel for six months now and they are working very well. I charge and discharge them each day. My other experiment is a huge home 48V home battery made from old Nissan Leaf cells and I have an arduino on each cell and they all talk to each other and I have been playing around with balancing algorithms in software and I *think* I have finally worked out a way to explain it. The simple explanation is if you have one of these 12V LifePO4 batteries, just leave it on the charger all the time. The BMS will sort it out. The complicated explanation. Let's say you have two cells, a 100Ah prismatic cell and a small cylindrical 13Ah and you put them in series. Let's say the small cell is almost fully charged 3.4V and the large cell is almost fully discharged, say 3.2V. Put a load on this battery and discharge it and the small cell will obviously discharge much faster than the large cell and the small cell will go flat first. But put a BMS on that battery during disharge and it would try to take energy from the higher voltage small cell and put it into the lower voltage large cell. That is actually the wrong strategy, but the BMS doesn't know about the capacity, it only knows about the voltage. So voltage and capacity are different things. Unless you know the capacity (which a microprocessor on each cell can do, but that is beyond a simple BMS) you can only balance when resting charged, or resting discharged. Go one step further, and you can balance resting discharged by topping up the low cells, or you can balance resting charged by discharging the high cells. Most BMS systems go for the latter as is simple to put a resistor across a cell. I looked up the specs for the BMS in the LifePo4 battery and I think it was only balancing at about 30mA. However, I think that actually is all it needs. It only is going to balance when fully charged though, so I figure if it takes 5h to charge the battery on a 20A charger, leave it on for longer so it can top balance.

[@philsrandomstuff2392]

Voltage and capacity are two different things I have found this out also myself. You can charge cells individually that start off with the same resting voltage and put 1 Ah into one cell and put 8ah into the other. This is where like you are saying a microprocessor on each cell that measures the amount of current taken out and put in to keep all cells at the same level would be an awesome idea. I built a lithium battery with isolated buck boosters on each of the cells and it worked awesome it’s just a very complicated thing to set up so to do it commercially it would be quite expensive.

[@ronmcgregor9324]

Thanks for your videos. I ordered 2 of these based on the promo price and description in their advert. Your video explained the short comings with connectivity and current draw. Returned the batteries and replaced them with the slighlty more costly renogy 100ah lifepo that can be connected in parallel and dèliver 100ah. Your explanatiins are helpjng me with my portable power project safety.

[@philsrandomstuff2392]

Hi Ron Cheep lithium batteries don’t like to discharge evenly which is why they have a low discharge amperage. But It’s hard to go past them for the price. Glad I was of some help 😀

[@ronmcgregor9324]

Am building portable 12v / 240v power for a moored boat. Needs to be reliable and safe. Your tips were very helpful.

[@MikeBanks2003]

Equalize or pre-connect using a couple of leads and a lamp socket containing a 50 watts globe. When the lamp goes out--batteries are pretty much equal potential. Common the negative rail, and put the lamp between the positive terminals--where it can pretty much stay indefinitely. Works for any battery type

[@PowerPaulAu]

Good to see you're back up and about again Phil. When running parallel loads (or charge) the connections should really be taken from one terminal of battery A and the other terminal of battery B. This ensures the load is spread evenly due to cable resistance. However your test showed a really odd result that the higher current came from the battery with the higher resistance (due to extra cable length), which supports what you're saying that these batteries shouldn't be pushed to their limits, and especially not past them. They're not made to a good electrical standard even if they look pretty, so they won't necessarily share the load properly like they should. BTW, I can supply the Heltec Active Balancers with a cut in voltage of 3.3v/cell, which avoids the need to switch them on/off like you're doing now. In practice I haven't had any issues with the original 2.7v/cell cut in voltage, but lower grade batteries will certainly be more prone to that unbalancing effect that you mentioned.

[@philsrandomstuff2392]

It’s good to hear from you Paul. I am on my way to recovery and starting to feel a bit better. I shot this video before my back injury and didn’t really like how it came together but decided to put it up anyway. Yes it’s definitely a funny result getting more current out of the battery that’s further away I purposely set things up with smaller cables to show that these batteries have their limitations. I would like to purchase some of your active balances off you and I’ll be in contact shortly.

[@bildad1234]

Hi Paul can you make the heltec active balancer cut in at higher volrage like 3.4v as it enters into the steep part of the charge curve? At 3.3v the cell is still in the flat area of charge curve.

[@PowerPaulAu]

@@bildad1234 possibly, but the ones I have, were supplied as 3.3v. Once stock has depleted I will consider revising it. In practice, there will be very little difference.

[@nicokypreos]

if you parallel the batteries they will balance themselves naturally, I have 4 of these in Parallel and with a 2000w inverter with max amp draw of 200amps, works sweet no problems, just string the power cables correctly fuse accordingly as you said.

[@herbertvonsauerkrautunterh2513]

I don't bother with the 100ah batteries. I buy the 200-300ah batteries. More cost effective as well. I actually add active balancing boards to power tool batteries I build additional to the BMS. Seems to work ok

[@philsrandomstuff2392]

You are 100% correct buying a larger capacity battery is more cost-effective. The problem is the AGM hundred amp hour size battery has been the standard for so long that it is sometimes difficult to fit the larger case 200 amp hour batteries in the same place without modifying the battery box.

[@insideoutback-hv2qz]

Thanks for the great videos Phil I have a VoltX 100AH 12v battery with what appears to be a dodgy BMS It reads 12.8v on the LED panel I opened it up and the cells read 13.2v Correct diagnosis? What BMS should I look for that will fit back in the case?

[@philsrandomstuff2392]

There are any number of BMS for sale on eBay. Get one that is suitable for the max load.

[@BadIdea1123]

Hey bud, I had batteries like these in parralell and series up to 48v The voltage for the bms is local to that batteries negative and positive. It's the same as putting a multi meter on a single battery in a 48v string. It will only read 12v The issue is that they don't balance. You can buy a 12v battery equaliser to solve that issue

[@yallawallahalla]

Hey the website is wrong apparently. They did say they would update it a month ago but they mustn’t have. The volt-x tech support have promised me that these batteries are actually rated for 100amps and the website is just outdated as the old version was 50amps.

[@philsrandomstuff2392]

That is correct the new ones will do 100ah, It’s even written on the BMS on the basic Battery that I cut open

[@craigtomkinson2837]

Nice work

[@Richo435a]

Thank you Phil. That was very helpful to get an idea of a cheap Li battery. It is interesting to see how the cheap end is progressing. VoltX was very bad but they are improving. It is worrying to see the simplest of issues like potential short curcuit danger. It is interesting to see they now have a spare year warranty. I wonder how warranty claims are delt with. Do you know anything about Kings Li batteries. They have good specifications like cell balancing that appears to be active. They have all the other features. They only have 2 year warranty.

[@philsrandomstuff2392]

You can only sell crap for so long until you have to improve it, otherwise people stop buying it. My experience with the warranty is unless you buy the batteries from voltX them self, good luck at trying to sort out any warranty as you have to take your claim back to the company that you purchased them from and then they can sort it out with voltX . As for the kings batteries, from the reviews that I’ve seen I think they are a worthy purchase for the price, and most people seem to be very happy with them, but there is no mention of active balancing in the spec sheet, just passive balancing from what I can read. I would like to cut one open to see how they are put together.

[@zoezoe610]

I have one of these in a battery box in the rear of the car and worked for one year. One day I went out and saw on the shunt that it was flat and had half a volt in it. There was no load on it just sitting in the box. I woke it up and put it on a charger and it would not go past 1.9% and put it back on the car so that the dcdc charger could try and charge it. Drove for an hour came back and it still said 1.9 %. Later I came back to the car to have a think about it and it said 100% and 13.24 volts. Contacted where I bought it and now have it to do some tests on it as even though it showed 100% how much of the battery is holding charge. Still waiting to here back from them. Any thoughts I said to them possible faulty board or failed cell. Cheers

[@philsrandomstuff2392]

Sounds very interesting. If you are, Battery is reading 100% capacity now, you could do a load test on the battery and see if it pulls a decent amp hour rating. If you flatten one of these batteries completely, you will need a power supply or a proper lithium battery charger to restart the battery. There is plenty of videos on KZbin on how to do this. But without seeing your setup and testing it , it is very hard to say what is wrong, whether it is a bad connection or something faulty with the shunt meter, or possibly the battery has failed. I’m sorry I can’t be much help these things are very hard to sort out over messages.

[@zoezoe610]

@@philsrandomstuff2392 Thanks for your reply. I woke it up and had it on a lithium charger but failed to charge . The shunt is good and have returned the battery to the seller for them to test it. Thanks again.

[@zoezoe610]

@@philsrandomstuff2392 What puzzled me was why it was good one day and then went dead flat with nothing drawing power off it.

[@philsrandomstuff2392]

@@zoezoe610 good stuff . I hope they have a new battery back to you soon.

[@zoezoe610]

@@philsrandomstuff2392 Me too, thanks

[@bildad1234]

Great vid Phil. When you parallel batteries you should have your output leads attached to the negative of one battery and the positive off the other battery so they draw current more equally. I was a bit confused as to which battery your 1st test sheet referred to, was it the more expensive one (wolf)? In your original videos of the first voltx was wondering how well it maintains balance after top balancing and recharging with active balancer.. It was pleasing to see that the cells maintained balance on recharge without active balancing. Be good to see how well cells are balanced after a period of time in use 3 mth 6 mth 12 mth.

[@philsrandomstuff2392]

I probably need to change the title on that video as this was done before I purchased these new batteries. Wasn’t really happy how the video turned out and never uploaded it but I thought what the hell. One thing I should’ve made more clear in the video was that I purposely set it up this way with the cables not connected correctly to show the inability of these batteries to discharge evenly. Even with the Cables connected like you suggest which is what I normally do it’s still discharged more out of the left-hand Battery. The test sheet is for the older series of VoltX batteries and this was to show just how quickly lithium batteries can become imbalance in the cells by continuously going past 80% Doc. All the batteries that I have worked on that have failed in the past have been used continuously past the 80% of discharge value, but in saying that they need to start off balanced to Have a flying chance.

[@philsrandomstuff2392]

Last month I went away for a three week trip used 30 to 40 amp hours out of the batteries every night , Had the active balances switched on all the time, got the capacity as low as 50% , 100ah out of the two batteries. After getting home and checking the individual cell voltages I can tell you they are where all identical, so whatever I’ve done has worked I am happy with the batteries so far. I think starting off with all the cells balanced correctly and recharging once you have used 80% of your capacity I think you will enjoy a long life out of lithium batteries

[@yallawallahalla]

@@philsrandomstuff2392 thanks heaps for your public testing. So very helpful!

[@melbournesubtropicfruits9474]

If these batteries function well id like to see an upgrading of the BMS video to something decent and where to source this BMS?

[@philsrandomstuff2392]

eBay if you would like to change the bms , they are not hard to change, bms comes with instructions on how to wire them up 😎

[@yallawallahalla]

Hey Phil, how easy would it be for me to install a new BMS into these? I’m an electrician but have minimal experience with electronics.

[@philsrandomstuff2392]

Not a problem at all Tim there’s plenty of videos out there and the instructions you get with the BMS show you how to make all the connections. The hardest part is cutting the battery open and mounting the BMS somewhere in the box.

[@yallawallahalla]

@@philsrandomstuff2392 great, thanks. Have you had any experience with a better BMS I could use? There are hundreds of the things and they all look the same to me.

[@philsrandomstuff2392]

It all depends on what you want from your BMS like how much discharge and charge current, Bluetooth, under and over temperature protection and so on. For me price is important no point putting a high dollar BMS on average cells. Below is a link to the Heltec bms I use customlithium.com.au/shop/spare-parts/bms/4s-120amp-hardware-bms/, and active balancer customlithium.com.au/shop/spare-parts/balancer/balancer-lifepo4-3s-4s-5a-active-balancer/ If you live in Australia the owner of this above business is very help full if you need help about there products.

[@yallawallahalla]

@@philsrandomstuff2392 thanks mate, I got two of the standard volt-x 100ah during the last eBay special. Gunna cut the tops off and see what I can do. Thanks heaps for your help mate, I’m in Aus yeah so will get in touch with the above BMS supplier. I’ll let you know how I go 👍🏼

[@philsrandomstuff2392]

@@yallawallahalla love to hear what you end up doing. Phil