Lithium Battery Question

[RogerD]

How much can you discharge lithium batteries?

What're your thoughts on buying out of China?

https://www.alibaba.com/product-detail/Deep-cycle-long-life-lifepo4-battery_60670051824.html?s=p

I contacted them to find out current pricing / volume discounts.

Here in the US, I see pricing from $750-$940 for 100ah batteries depending on the manufacturer.

Other than the initial cost, they seem like the way to go. Half the weight and you only need about half the number of batteries to achieve same usable amp hours, since your not limited to 50% max discharge.

 

[John61CT]

I would only source direct from very well recommended vendors.

Yes that is US market pricing.

I stop at 12V, maybe 10-15% SoC depending on Amps rate. But only in a pinch, try to size for some reserve if solar only

Shallower is better for longevity

 

[Van-Tramp]

Lithium batteries are amazing. I have a 200ah which did cost in the range you state.

I may be wrong, but aren't all Lithium batteries made in China? So no matter who you buy it from, it will be Chinese.

You can bring lithiums down to 10% from time to time. 20% seems to be the harmless in every way

 

[frater secessus]

The cells/pouches/etc are from China but some are packaged in the US.

I think John's concern is not with the internal cells proper but with the packaging and electronics supporting those cells. And with the ability to get replacement if something fails. Correct me if I am off-base, J.

 

[jonyjoe303]

You can take them down all the way to zero percent, the BMS will shutoff at that point. I took mine there before. It won't damage them, they will still outlast lead acid by many years. But it take a long time to get them to zero percent, usually cloudy weather where you don't charge back up every day. 

Those are good prices at alibaba, but I tried to order some balance modules from them before and the shipping costs are tremendous. I would have to buy serious quantity of balance modules for it to be cost effective for me.  

Myself I like to see whats inside a battery case to see if I'm getting the real deal. I seen lithium batterys rated at 30ah but that wasn't there true rating, what they were advertising was that it was comparable to a 30ah lead acid (but it was in small print). But I notice the 100ah battery weighs 33 pounds, which is about right for lifepo4, thats about what my battery weighs. And when I built my lifepo4 I paid 160 dollars for the 80x lifepo4 cells(chinese made) that I had to use, so I can see them building them in the 300 dollar range especially if they use the same cells I used.

 

[tbair]

Lithium batteries are amazing. I have a 200ah which did cost in the range you state.

What do you use for batteries, would be curious as I am getting ready to do renogy 100AH for around $800 and would love 2x the AH for a similar amount.

 

[Van-Tramp]

Mine is a Life blue 200ah. It did cost just over 1800 last year

 

[tbair]

Thanks

 

[RVTravel]

Roger, did you decide to try these batteries? Their warranty seems less than offered in the states and I wonder if the max charge current might be limiting?

 

[Ticklebellly]

How much can you discharge lithium batteries?

 
I've set a Low Voltage cutout at 11.8V for my 4 cell battery packs.   The battery packs were constructed from individual cells.   Still playing with max charge voltage at 14.1 but likely to go to 14.4.   I am also not floating batteries, just charging then using all the way down to 11.8.

 

[Ticklebellly]

Just followed the link. I notice Li Ion written on the pictured battery and a confusing "Deep cycle long life lifepo4 battery pack 12v 100ah RV li-ion battery pack" text in the data. Further on the guts of the battery is described as 4S4P. I would be getting a clarification on what technology is in use before ordering anything.

 

[John61CT]

SEO verbiage.

 

[Weight]

4S4P usually means four 3 volt batteries wired in series for 12 volts. Then four (25ah) series sets wire in parallel for 100ah at 12 volts.

 

[MrAlvinDude]

Ebikeschool.com (https://www.youtube.com/channel/UCRMrqzsrPIWvY3PINkLKs-Q/featured) mentioned this aliexpress shop (https://liitokalahongkong.aliexpress.com/store/217753) to be the only shop that he would consider buying lithium batteries in small quantities from (<1000 pcs at a time).

[Edit] Ah, but now I see that you want 12V replacement batteries. Not what this store is about at all.[/Edit]

 

[John61CT]

4S4P usually means four 3 volt batteries wired in series for 12 volts. Then four (25ah) series sets wire in parallel for 100ah at 12 volts.

Parallel should be wired before series.

And that should be what 4S4P means, as opposed to 4P4S.

and each cell is nominal 3.2V

 

[John61CT]

Ebikeschool.com (https://www.youtube.com/channel/UCRMrqzsrPIWvY3PINkLKs-Q/featured) mentioned this aliexpress shop (https://liitokalahongkong.aliexpress.com/store/217753) to be the only shop that he would consider buying lithium batteries in small quantities from (<1000 pcs at a time).

I saw it on the internet so it must be true