Just Place new Order on Alibaba- 280AH x 8 for 1260.00 USD Delivered, Grade A to Canada

[nosys70]

not received yet, so can't say, but probably yes since it is delivered by UPS

 

[Deleted member 4428]

I apologize, I should have directed the question to MNDARE

 

[rayfound]

These seem like an insane deal on a really compelling battery for an RV... 280AH @ 12V, which could be DIY built for something like $700 with a box and full featured BMS... is there something I am missing here? (aside from not actually NEEDING more than the 125AH capacity I already have)

 

[mndare]

Should not be an issue

Did you pay any taxes, tariff, duty or brokerage fees on top of the $1132

No extra fess, duties, or taxes. All of that included in UPS shipping price. NO SURPRISES

 

[mndare]

Look Gang, no bullshit. I have now tested 4 of 8 of these cells for capacity and all are scoring between 98-104 % capacity. I can only say I am so impressed that I am ordering 8 more cells. Will be quite a delay with the corona virus crisis but will get eventually.

 

[mndare]

OK here are some of my pictures and videos. When I get my BMS I will finish this 560AH 4S2P pack build and see the balancing requirements and do a full pack capacity test.

 

[Steve_S]

Look Gang, no bullshit. I have now tested 4 of 8 of these cells for capacity and all are scoring between 98-104 % capacity. I can only say I am so impressed that I am ordering 8 more cells. Will be quite a delay with the corona virus crisis but will get eventually.

I was told yesterday during our long chat (3 hours+) that shipping would commence on Feb.05 and that shipments are being queued up according to order date. Now just my assumption but I think that orders have been piling up over their holiday period and as such there will likely be a backlog. I think it's safe to say that anything ordered in the past two weeks will be backlogged for a little while.

 

[JoeHam]

OK here are some of my pictures and videos.

Thanks for all you are doing mndare despite the extra noise you have endured. I may have missed it but do you have a link to videos as well? I only see the three pictures.

 

[mndare]

Had a little accident last night with my wife spilling a cup of tea across my laptop....video still to come

 

[mndare]

Ordered another 4x280 AH cells.

 

[MondeoMan]

OK Results on first Cell Capacity Test: 105% capacity, 294 AH for the first cell tested. I am going to test another cell starting tonight.

Can you please share exactly how you charged / discharged them?
I.e. charging max current, max voltage and cutoff current, discharge current (30 A ?), discharge cutoff voltage?

Thanks!

 

[mndare]

Fully charged to 3.65 volts using a bench adjustable charger at 15 amps, Load tester bench unit to discharge at 30 amps, same meter as Will uses to measure amps and watts.

 

[mndare]

I have been into lithium for some time, Built large banks starting 5 years ago for sailboat...

 

[mndare]

Have all the right equipment for managing and testing these systems. Not a newbie at this. Yes would be nice to do a 1C type test but my banks add up to 1200 AH so I will never charge at near a 1C rate and on a sailboat even with a water maker and a fridge on I never draw close to 30 amps

 

[MondeoMan]

Fully charged to 3.65 volts

How do you decide when it's fully charged?
As soon as the voltage first hits 3.65 volts?
Or when the current drops to 0 Amps?

I have been into lithium for some time, Built large banks starting 5 years ago for sailboat...

I apologize for asking, I do not want to question your knowledge, I want to learn from your experience.

 

[ghostwriter66]

How do you decide when it's fully charged?
As soon as the voltage first hits 3.65 volts?
Or when the current drops to 0 Amps?


I apologize for asking, I do not want to question your knowledge, I want to learn from your experience.

When the amps hit 0

 

[jasonhc73]

$175.78 / kWh
New cells.

 

[mndare]

How do you decide when it's fully charged?
As soon as the voltage first hits 3.65 volts?
Or when the current drops to 0 Amps?


I apologize for asking, I do not want to question your knowledge, I want to learn from your experience.

Yes when the amps drop to 0.1 amps at 3.65 V then they would be considered fully charges

 

[mndare]

For discharge I looked at the AH at 3.0 Volts, 2.8 Volts, and 2.5 volts which is the cutoff discharge voltage for these cells. The difference in amp hours between when the cell hits 3.0 volts and 2.5 v is about 15 AH only. A very steep slope when the voltage drops to 3.0 volts and below. I will be setting my voltage cutoffs to 2.8 volts for the BMS.

 

[mndare]

$175.78 / kWh
New cells.

I get 187.50 USD/kWh if using 12 volts in the math

 

[jasonhc73]

Yes when the amps drop to 0.1 amps at 3.65 V then they would be considered fully charges

To sum up, for long and happy LFP battery life, in order of importance, you should be mindful of the following:

1. Keep the battery temperature under 45 Centigrade (under 30C if possible) – This is by far the most important!!
2. Keep charge and discharge currents under 0.5C (0.2C preferred)
3. Keep battery temperature above 0 Centigrade when discharging if possible – This, and everything below, is nowhere near as important as the first two
4. Do not cycle below 10% – 15% SOC unless you really need to
5. Do not float the battery at 100% SOC if possible
6. Do not charge to 100% SOC if you do not need it

 

[mndare]

To sum up, for long and happy LFP battery life, in order of importance, you should be mindful of the following:

1. Keep the battery temperature under 45 Centigrade (under 30C if possible) – This is by far the most important!!
2. Keep charge and discharge currents under 0.5C (0.2C preferred)
3. Keep battery temperature above 0 Centigrade when discharging if possible – This, and everything below, is nowhere near as important as the first two
4. Do not cycle below 10% – 15% SOC unless you really need to
5. Do not float the battery at 100% SOC if possible
6. Do not charge to 100% SOC if you do not need it

Just asking are you making a specific point about this discussion thread...?

 

[jasonhc73]

Just asking are you making a specific point about this discussion thread...?

Don't charge to 3.65.

 

[mndare]

We are doing a capacity check, so you have to fully charge the battery to see if the true capacity is to spec. The issue is not the 100% capacity, it is floating it at 100%. These batteries were immediately discharged when they hit 100% as part of the test and my packs are never float charged at 100%. They are stored at 40% capacity during the off season of cruising. My 5 yr old pack still capacity tests at 100%. I own a Tesla 90kWh pack so I understand your points very well. Have you said the same to Will when he does his capacity test videos??

 

[MondeoMan]

I've seen some LiFePo4 datasheets that define these:

Fully charged: charge with 0.3C - 0.5C, up to 3.65 V, and cutoff when the current drops below 0.05 C (i.e. 14 Amps for 280 Ah).
Some manufacturers specified [3.6 Volts and cutoff at 0.02 C] instead of [3.65 Volts and cutoff at 0.05C].

Fully discharged: discharge with 0.3C - 0.5C, cutoff when the voltage reaches 2.5 Volts.

Based on these definitions, charging to 3.65V and 0 amps is a bit overcharging. Probably not harmful if it does not happen very often and the cell does not stay in this condition for very long, but it might also explain why the cell returned 294 Ah.