Apexium DIY Battery Kit Build - Seplos BMS V2 (10E)

[@natesdiysolar]

Apexium 48v DIY box: www.alibaba.com/product-detail/detail_1600909932053.html?channel=minisite_a2706.wshop_index.29162.i2&scenery_id=2&tracelog=a2706.wshop_index.29162.i2&spm=a2706.wshop_index.29162.i2&wx_navbar_transparent=true

[@tiborchren]

I'd have one tip for you to consider. The rear battery cells only support the square beams in the centre, top and bottom of the rear wall. The battery cells will expand over time and it would be better if they had full support for their complete surface on the back wall. It would be good to fill the rear section with precision cut wood in the gap between the rear beams or put aluminium plates in the back on the rear wall. I know it requires disassembling the whole battery, but it's worth considering. I saw on another KZbin video that they filled it in so that the rear battery cells also have back wall support across their full surfaces.

[@natesdiysolar]

Good point. I may just do that then. Where did you see that.. off grid garage?

[@tiborchren]

@@natesdiysolar I saw it first time on kirkdis channel where he used wood filler to solve it, then I posted it in the comments to Andy from Off-Grid Garage when he was making a Frankenstein DIY battery box and based on that comment he made a video where he used an aluminum plate in the back of the box.

[@Mike-01234]

One reason I didn't buy Apexium same thing with their vertical box those two holes at the bottom of the box left no support for one side of the battery to balloon out. The only real way to fix it is cut out the center weld in a plate 10 gauge steel repaint it.

[@Graham-ot7bm]

I added a 3mm stainless steel plate to even out the pressure. I now see the box design has changed to incorporate a flat plate.

[@MatthewYBarbo]

Very clean setup that is easy on the eyes. Another great video, Nate! Awesome job as always!

[@natesdiysolar]

Thanks

[@daviebaggins]

Thats quite a setup🎉🎉🎉

[@ShaneS071]

A disconnect needs to be added to these units, have 2 of them and if the bus bar that they are connected to is live the unit will start charging or discharging no mater what position the push button is in

[@natesdiysolar]

Yes, that certainly is the case. They now include a disconnect.. I have switched to the Yixiang box now, and it has a disconnect. Can't remember if there is a option in the bms settings for that

[@dustanltye]

Awesome build! You are hired! Sending you plane tickets to ky!

[@natesdiysolar]

Lol

[@TechNTorque]

Very nice! I've been looking for the last month for your next video! I'm selling all my lead acid batteries and buying 280ah cells if I find a deal on 16. I'm going to wait to see how this enclosure turns out instead of building my own. Can't wait for part 2!

[@natesdiysolar]

I'll be testing a couple of different ones. What really matters is what bms you get. All the enclosures are pretty standard now. In the 2nd build, I'll list the cost of everything as well.

[@TechNTorque]

@natesdiysolar I didn't buy anything yet, but overkill solar is at the top of my list for programming and features right now. The 16s 100A bms looks like it checks all the boxes and decent reviews. I live in the northeast so I'll need low temp protection here. I'm not buying anything until I see your videos 😄

[@natesdiysolar]

@TechNTorque cool. Keep in mind unless you are going to have more than one battery you will be able to get about 5kw of power out of that bms before hitting 100a.

[@TechNTorque]

@natesdiysolar one battery to start, going to scale up in the future. Just looking to take a few light load circuits off grid such as my refrigerator and some lights to run off solar/battery at all times. Hoping to keep a few things running all the time so I don't have to worry about power outages. When I scale up I'd like to have everything off grid, but still grid connected if needed. How do you feel about the 6000xp inverter?

[@Joeboxtruck-m9c]

So these batteries vent fumes ? Is this battery kit unsafe inside an RV ?? By inside I mean in the living area under the bed. Thanks !

[@natesdiysolar]

They do not vent fumes under normal circumstances. They have safety vents in case of overcharge pressure. I have never seen one vent personally, even when overcharged. If you look up lifepo4 or lfp battery cells, there are a lot of good info on them. Not to be confused with lithium ion or LTO. Iv seen people install lfp batteries pretty much anywhere. Just avoid high ambient temperature for longevity.

[@curious-homebody]

i was just i Thailand for 2 weeks up in Phrae. Sawadee cop 🙏

[@natesdiysolar]

Awsome. How did you like it.. was it your first time.

[@curious-homebody]

@@natesdiysolar i loved it! i wish my employer would allow me to work remotely from there! i last went in the 1980s. first time back since. i also became a Thai citizen during my stay!

[@natesdiysolar]

@guyin916 oh did you.. I need to do that.. long term.

[@Scat.original]

do you have a link to purchase this DYI BOX?

[@natesdiysolar]

You can find it on alibaba and also in video description. If you want minimal building I suggest looking at it yixiang box. You can find the video and links on my channel. www.alibaba.com/product-detail/detail_1600909932053.html?channel=minisite_a2706.wshop_index.29162.i2&scenery_id=2&tracelog=a2706.wshop_index.29162.i2&spm=a2706.wshop_index.29162.i2&wx_navbar_transparent=true

[@marksanders7305]

Ok my battery box was a stand up box !

[@natesdiysolar]

How did you like it?

[@Graham-ot7bm]

Congratulations on reinventing electrical theory regarding current flow in a series circuit- or not! Of course the current flowing around a series circuit like these batteries will be the same at any and every point in the circuit. Take another look at your meter reading. The first reading is positive but when you move for the second reading it is negative because the current is flowing in a different direction through the meter. On a high quality meter the digits will be the same only the + or - will change. Your meter may have an offset (zero) adjustment that may need a tweak. Where you put the batteries in the series circuit will make no difference what so ever.

[@natesdiysolar]

Thanks for the info. Don't you think resistance down the line would be additive, causing the current to be higher.. oftentimes, when you have multiple batteries in series, you will have balance issues . Meter can't be that off.

[@Graham-ot7bm]

@@natesdiysolar Just turn the meter around on the same bit of cable and check. The meter can be influenced by other magnetic fields or cables carrying high DC current. Where the resistance is located in a series circuit makes no difference. IE it could be at the start or the end of the loop. The current flow will be constant and equal at every point in the loop.

[@franciscofernandes4527]

Is it worth build a battery for one year warranty when i can buy one for 10 years warranty,

[@natesdiysolar]

It's a kind of personal decision, right.. it's a learned confidence from experience. Personally, I think it is very worth it. What company said one year? I know some that will honor a 10 year. In this video, I show a price comparison and warranty info. kzbin.info/www/bejne/jaCmp2CFoNKmd8U

[@franciscofernandes4527]

Which company offer 10 years please!I think the company I saw 1 year is Fogstar

[@natesdiysolar]

@@franciscofernandes4527 please see my other comment. The yixiang

[@offgriddreaming5403]

How do you like the seplos bms please?

[@natesdiysolar]

Well . The v2 bms is slow to balance initially but once you get to using it it's really not that bad.. it functions lol. The display is lacking compared to the jk Touch screen. I'll be doing a video about balancing with this bms. But it was frustratingly slow. If you want quick and easy just use the JK inverter bms or an externalbalancer. Videos coming out soon on both of these bms. I can't really say I'd recommend it over the jk bms... that said I haven't gotten into the comm/inverter functions yet... the v3 does have a 2 or 3A balancer so if they had a better screen AND balancer I would be ok with it...

[@offgriddreaming5403]

@@natesdiysolar Thanks for the quick reply. Yes I have 12v jk bms and really like it. I've ordered a box similar to yours with the seplos. I wish it had the jk but am willing to give it a try 👍🏼

[@natesdiysolar]

@offgriddreaming5403 just be sure to pre balance by putting Cells in parallel or just use an external balancer for the initial balance. You will be fine. What Box did you go with..

[@offgriddreaming5403]

@@natesdiysolar I only have 105ah cells so I went with a box by battery queen lol. I believe it's a rebranded seplos. I'll probably do a video once the box arrives. I'm just testing the cells now

[@christalbert722]

Uhhhhh....... they're in series, they should all see the same amount of current. Voltage cell to cell may differ, and when the BMS is running balancing things you've got multiple current paths so that's a different critter, but initially when you've just got 16 cells in series.... I can't see how the current would vary.

[@natesdiysolar]

That's what I was thinking especially in parallel but in series u also have internal resistance of each cell adding up ... I was surprised to see more current on the meter when probing the 2 ends of the pack

[@natesdiysolar]

That's what I was thinking especially in parallel but in series u also have internal resistance of each cell adding up ... I was surprised to see more current on the meter when probing the 2 ends of the pack.

[@nottelling41]

No, you missed an obvious difference: you're measuring the current direction positively and then negatively. It is a bias flaw of your meter

[@natesdiysolar]

​@nottelling41 is there a way to measure it accurately..

[@nottelling41]

@@natesdiysolar you would need a few especially accurate alternative current measurements and then average them and then compare to your positive and negative direction currents to see which is most accurate or you could time average to see if forward or reverse was closer to the total charge eventually. I'd just guess that forward is more accurate and then there is a50% chance you're correct with no work required :-)

[@daviebaggins]

Weee