12v 190ah lifepo4 from aliexpress

[nosys70]

the force on the bolt is indicated on the datasheet (Eve cell) , maxt 8kg. More you risk to break the case.
the size of the screw does not matter but since the surface contact will be better with small screw, you can say the smaller, the better, but make sure the head is large enough and use a copper washer and better, slotted busbar (slotted holes increase surface contact.)

you can also polish busbar at surface contact.
the surface contact is a circle about 20mm diameter, that is a lot enough.
since the busbar should be around 1mm2 per Amp, if you want to use 1C, then you need around 200mm2

 

[ScoTTyBEEE]

Thanks for the great information, however I'm a little confused. It sounds like all the terminals have a threaded metal insert that you replaced with heilcoils. Do you know the size of the heilcoils? I'm not sure what a "grub screw" is. I see the 4 cells come with what appears to be 8 flat head screws. They do look too short to use with a washer, buss bar, and a BMS wire ring terminal. What did you superglue, the new helicoils or the screws?

I'm planning to use these cells in my travel trailer, so they will get bounced around a lot. I'm a little concerned that it may be difficult to make connections that won't loosen with vibration. Perhaps some Blue Locktite® Threadlocker is in order on the screws. I don't mind doing a little work replacing the metal inserts and new screws if that will really make solid connections (both electrically and mechanically).

I love the connections on the Fortune 100ah cells that Will showed recently, but they cost about twice as much for the same capacity as these 190ah cells and the Fortune cells are much larger.

What does everyone think of using an oxide inhibitor (like electricians use with aluminum wire connections) on top of each aluminum cell terminal?

The terminals have steel threaded inserts in them, that is a helicoil, I replaced my broken one with the same thing, they’re m6. A grub screw is just the screw shaft so it lets you place a nut over the top, probably just has a different name where you are, blind screw perhaps. I put superglue on the (longer) grub screws and tightened them in, it would glue everything in place. I had to sandpaper the terminals after the glue had dried as the gas created a bit of a film over them, I just used regular loctite super glue, nothing fancy. If you want to ensure the nuts don’t work lose then threadloc or just put 2 nuts on but I think it will be ok, normal batteries don’t have problems working lose.

 

[Ely]

I placed my order the 24th of december last year and i`m from switzerland. Since the 8 of january I‘ve received a UPS-label saying me that my goods were in Nuernberg (Germany) aprox. 4 car-hours from me. So, I`m waiting and waiting and... LOL

I think the German customs is the problem. The customs here are in greater parts an analog business and therefore it can take a lot of time to finish the customs declaration.

In 2018 my order from Hong Kong sits about 8 (eight! EIGHT!!) weeks at the customs. It's so crazy ...

 

[Carly]

the force on the bolt is indicated on the datasheet (Eve cell) , maxt 8kg.

I believe the force is given as torque, Newton-meters, not kilograms. >8 Nm, or >5.9 foot-pounds and 70.8 inch-pounds*. You would need a torque wrench to apply this torque accurately. *Note this is for the 280AH Eve cell, reference below.

 

[nosys70]

yes , my bad, 8Nm is 800grms meter, so very small force is needed. this means you should not even need to force with hand.
possible that is what makes these cells so cheap.
That is also why your busbar must be pretty slick and slotted.
don't know if you can add some conductive paste or powder (stain ? micronized copper, silver or aluminium ?) to improve contact.
ideally a thin sheet of gold would be the best.
sheet of gold cost nothing

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[tgg]

The terminals have steel threaded inserts in them, that is a helicoil, I replaced my broken one with the same thing, they’re m6. A grub screw is just the screw shaft so it lets you place a nut over the top, probably just has a different name where you are, blind screw perhaps. I put superglue on the (longer) grub screws and tightened them in, it would glue everything in place. I had to sandpaper the terminals after the glue had dried as the gas created a bit of a film over them, I just used regular loctite super glue, nothing fancy. If you want to ensure the nuts don’t work lose then threadloc or just put 2 nuts on but I think it will be ok, normal batteries don’t have problems working lose.

It all makes sense now. Thanks again.

I found another method of securely bolting to these types of terminals. Check out drawing D here: https://diysolarforum.com/threads/eve-280ah-lifepo4.2175/post-19916

you can also polish busbar at surface contact.
the surface contact is a circle about 20mm diameter, that is a lot enough.
since the busbar should be around 1mm2 per Amp, if you want to use 1C, then you need around 200mm2

This is very useful. Thanks much.

I'm much more confident in using these cells thanks to the info from this forum.

 

[tgg]

This appears to be a cheaper source for these same batteries. However, I'm not familiar with this seller and there aren't any reviews.

Buy Products Online from China Wholesalers at Aliexpress.com

 

[lmwilco1]

I ordered 4 of these batteries on Dec 31st, they are currently in customs in LA, hopefully I will get them in the next week or so.

 

[ggoldfingerd]

I ordered 4 of these batteries on Dec 31st, they are currently in customs in LA, hopefully I will get them in the next week or so.

Did you order with the free standard shipping?

 

[lmwilco1]

Yes, standard free shipping

 

[ggoldfingerd]

Yes, standard free shipping

Thanks. I found one listing where the expedited shipping was $80 more than free shipping for the 8PCS I want. However your seems to be fast enough so that extra money can go into a BMS.

 

[KauaiMolokai]

Shipping is never free. It is either included in the price of the product, in which case the shipper will use the lowest possible cost shipping method. Or it is added on specifically, in which case the buyer may be given the option of various shipping methods. Due to various postal treaties, Chinese companies are able to ship "small" items at very, very low cost, often much cheaper than I can ship the same thing (light and small) from LA to say Dallas. Sometimes Chinese companies ship in bulk to a US (or other) warehouse and then ship to you from there.

Of course it doesn't matter to you as the buyer if shipping is "free" or extra; the total cost to your door is what determines how much you pay.

When looking at larger/heavier items its worth knowing that if you ship as part of a container load that once you factor in all the costs (customs, dock fees, warehouse fees, collection fees, etc, etc) this total comes to roughly the same as shipping the same items Fedex to your door! Its only once you order a full container that you save money. I learned this the hard way ;-)

 

[lmwilco1]

I just got an update from Fedex that my batteries were delivered to them in Carson, CA. No estimated delivery yet. I ordered them on Jan 31st.

 

[Bob B]

I just got an update from Fedex that my batteries were delivered to them in Carson, CA. No estimated delivery yet. I ordered them on Jan 31st.

I finally got the same notice .... ordered mine Jan 6. Thought I was going to get in ahead of the holiday ... but didn't happen. I was just about ready to open a dispute.

 

[lmwilco1]

They finally arrived, I ordered on 12/31. Three of the cells are at 3.69V, one cell at 3.71V, Should I connect them in parallel to equalize before assembling my pack?

 

[Bob B]

That's exactly how mine came packed.
I checked the starting voltages and all between 3.281 and 3.283. I was pretty surprised they were that close. How well my meter was making contact could account for that.
The terminals all look brand new .... so either they replaced them or they are all new.

Not sure if there is a Mfg date .... there is a tag on top that is hard to read on several of them. The bottom # looks the same on all and the top # is defferent on all.

I wore rubber gloves and wiped down EVERY surface with a damp bleach cloth.

 

[lmwilco1]

Started the battery build. I used VHB tape between the cells and a couple of tie wraps to keep thinks tight together. I have it all assembled on a table for testing before I install in the camper.

Wiring for the BMS cell monitor, I have a 150A fuse on the positive terminal and there is a temp sensor also attached to the positive terminal. I need to get a 200A fuse for the main battery fuse.

Here you can see the 45A charger with a 50A circuit breaker, 2000W Renogy inverter, the shunt and power monitor. The BMS is on the left side of the battery. It is a 100A BMS from battery hookup, I will replace it with a Chargery when it arrives from China.

Once the battery finishes charging I will put a load on the inverter and see what capacity I get out of the pack.

 

[lmwilco1]

I finished the load test and got 185.96AH using the aliexpress 150W tester. When I was charging the battery the BMS was shutting off charging while I was still pushing 10A into the pack due to individual cells going over the max voltage limit. I think if I top balance the pack I will probably get above the 190AH spec for the batteries.

 

[tonyvincent]

If you use load test directly, will there be some power loss? I mean, the power factor of the load

 

[lmwilco1]

I don't believe that power factor applies to DC, only AC circuits.