diy solar

diy solar

Xuba Electronics: DEAL - 280AH LiFePo4 cells. Purchase & Review

They just require the Li batteries to be under a certain SoC when shipped by air (IIRC it's 30 %) ;)
All the "outside of equipment" lithium batteries I order as part of my day job come in at about 20-25%, so yes.
 
Hi Steve S

I'm new to this forum. Comfortable with sorting electrics but LiFe technology is new to me.
Retired aboard my Catamaran and currently hiding from hurricanes in Chesapeake Bay
Based on your write-up I just placed my order for 24 x 280Ah Xuba cells to replace my gel bank (24V 800Ah) - thanks.
Did not think about buying bussbars :( - will try get them to add to order.

Quick background on inputs;
2 x Victron 5000 24V multis + 1 x Mastervolt 24V charger - each 100A charging capacity with LiFe settings.
5 x solar arrays via Victron MPPT's - 3400W total
2 x 120A 24V auxiliary alternators with MasterVolt controllers
2 x Eclectic D400 24v wind chargers

"normal" power draw is 20A /24V - 14kW per day
Maximum power draw is 500A for max 1 minute (bow thruster)

Questions / advice / comments please
Does it make sense to set up 3 banks of 8 cells each so that each charger will work independently? Given that they will all connect to the same output busbar anyway, not sure how to achieve this or whether its even necessary. Further complicated by solar/wind/alternator inputs.
Any recommendations on BMS? Presume 3 x 8s 150 Amp in parallel? Would be nice if the BMS units communicated with each other too - so that all 24 cells stay balanced. Not sure what the BMS Amp rating refers to (input, output or both?)
It has been suggested to me that I use a Victron Cyrix Li-ct 24V 230 A on my alternator inputs - alternatively Victron Battery Protect 220A?
Can you think of any other protection "gadgets" I should add?

Any input will be welcome
Thanks
 
Did not think about buying bussbars :( - will try get them to add to order.

most of the companies send bus bars with the cells, unless you are not happy with what they send you should be fine....some requestb they send double bus bars.
 
most of the companies send bus bars with the cells, unless you are not happy with what they send you should be fine....some requestb they send double bus bars.
Thanks Michael
I'll wait & see. I have some 1/4" x 1" copper rails so can make if none arrive.
 
well , Korean Air, this explains that...
I used to fly Korean Air a lot eight and nine years ago. Then I read one of those "why things happen" books that described how the flew into a mountain on Guam a few years earlier. I think they fixed the problem but I now go to China on a different route.
 
I just received my pack of 4 cells and having an issue when charging. They all started out within 4mv of each other, but once i started charging, one of them jumped up to +100 mv compared to the others and the difference stays after the charge is removed. I verified with my multi meter. Has anyone had this issue, any advice? My multimeter isn't good enough to check internal resistance.
 
Thanks Michael
I'll wait & see. I have some 1/4" x 1" copper rails so can make if none arrive.
The Bus bars XUBA included will work when the cells are in a 1 x 8 straight line. If you want to arrange them in a 2 x 4 pattern, you will need to make the bus bars that run side to side.
 
I just received my pack of 4 cells and having an issue when charging. They all started out within 4mv of each other, but once i started charging, one of them jumped up to +100 mv compared to the others and the difference stays after the charge is removed. I verified with my multi meter. Has anyone had this issue, any advice? My multimeter isn't good enough to check internal resistance.
Did you parallel "Top" balance the cells, to 3.650V, before building your Battery? I have seen mine vary about 0.030V (max) from each other depending where they are in the charge/discharge cycle. Most BMS's that passive ballance, does so, when the cells are charging above 3.4V...
 
Did you parallel "Top" balance the cells, to 3.650V, before building your Battery? I have seen mine vary about 0.030V (max) from each other depending where they are in the charge/discharge cycle. Most BMS's that passive ballance, does so, when the cells are charging above 3.4V...
They were all within .005V of each other from the factory and I connected them in parallel for a few days, I expected the balance to be off at the higher end of charge but not as much as +.1 V
 
Still not clear. You said you hooked them up in parallel. Did you fully charge the cells when you had them connected in parallel?
 
They were all within .005V of each other from the factory and I connected them in parallel for a few days, I expected the balance to be off at the higher end of charge but not as much as +.1 V
Passive parallel balancing doesn't really work. You need to charge them all to 3.65V in parallel at least once. With a CC/CV power supply some will reach full before the others, but they will all equalize when you're done. The full ones stop taking more voltage, because the PS will not send more than 3.65V to the whole. The slower ones catch up with the fast one in that way. It really does matter and needs to be done one time at the start. You won't know for sure, if there is a problem cell without TBing them.

It's like installing spark-plugs without checking their gap. Sure they're suppose to come gapped alike, but you don't know for sure.
 
Passive parallel balancing doesn't really work. You need to charge them all to 3.65V in parallel at least once. With a CC/CV power supply some will reach full before the others, but they will all equalize when you're done. The full ones stop taking more voltage, because the PS will not send more than 3.65V to the whole. The slower ones catch up with the fast one in that way. It really does matter and needs to be done one time at the start. You won't know for sure, if there is a problem cell without TBing them.

It's like installing spark-plugs without checking their gap. Sure they're suppose to come gapped alike, but you don't know for sure.

Yea they were passively charged, thanks for the advice, I've got a bench top power supply coming in tomorrow and will do! I think it is an imbalance issue - its happening right at the end of charge
 
Amy told me all DIY Solar Forum members get free buss bars. And she lowered my shipping price a lot. My price for 16 batteries including shipping is 1710.32
Amy confirmed that there won't be any customs duty.
I'm having trouble getting my credit card to go through but I will make the payment one way or another.

Also, there are three different links on the Xuba site for 280ah batteries. One describes them as deep cycle. Amy confirmed that they are all the same batteries.
 
Thanks HRTKD. I started the appeal process. I'm not in a hurry. I still need to gather all of the other pieces of my solar system.
I plan to buy a bunch more batteries if these work out.
 
Thanks HRTKD. I started the appeal process. I'm not in a hurry. I still need to gather all of the other pieces of my solar system.
I plan to buy a bunch more batteries if these work out.

As I recall, getting to the appeal status screen is impossible once you've closed it, unless you have the super secret URL. I posted that URL in this thread, a couple pages back. I couldn't find that status, so I tried to buy with a different credit card. Same result so I appealed that card too. Now I have two cards approved for use on Alibaba.
 
Back
Top