Poey50
Well-known member
I can't help thinking that life would be easier if you agreed to stay a bit dirtier.
270ah DIY LiFePO4 build
- Thread starter Poey50
- Start date
Kelpie
Well-known member
If prices continue to fall like this, surely lead acid will become the expensive option for those who don't wish to
Yup. I had been expecting an additional bill but no sign of that.
Poey50
Well-known member
I think lead acid will have a place for a while since it is so tolerant of abuse and people are just very used to it. Three things may change this, I believe: 1. the continuing drop in prices, 2. the emergence of more straightforward LFP systems, and 3. a greater understanding of the remarkable properties of LFP.
On this last point, it's worth mentioning the latest update of Rod Collins (today on another forum) author of the seminal Marine How To article listed in my opening post of this thread. He's had his Winston pack for 12 years now which has done over 2,000 cycles most to 80% depth of discharge or deeper. These still deliver slightly more than 100% of their rated capacity. If it wasn't Rod Collins, I simply wouldn't believe it.
mitiempo
Member
Yes, prices are dropping if you buy from the right places.
I have on the way 8 Calb CA180 cells purchased for $80 US each. New grade A cells with extra busbars. With shipping - China to Victoria B.C. - 902 US. That includes all duties etc.
That converts to $1179 Cdn.
For comparison 4 Trojan T-105 purchased locally would be $960 Cdn. Pretty close.
But the comparison doesn't end there. The Calb used from 10% to 90% give me 320 AH. The Trojan are 440 AH total in series/parallel so usable is 220 AH.
To get comparable AH (330) out of Trojan T-105 requires 6 for a total of $1440.
So in that respect the Calb are less expensive. Not to mention all the other advantages of LiFePo4.
I have on the way 8 Calb CA180 cells purchased for $80 US each. New grade A cells with extra busbars. With shipping - China to Victoria B.C. - 902 US. That includes all duties etc.
That converts to $1179 Cdn.
For comparison 4 Trojan T-105 purchased locally would be $960 Cdn. Pretty close.
But the comparison doesn't end there. The Calb used from 10% to 90% give me 320 AH. The Trojan are 440 AH total in series/parallel so usable is 220 AH.
To get comparable AH (330) out of Trojan T-105 requires 6 for a total of $1440.
So in that respect the Calb are less expensive. Not to mention all the other advantages of LiFePo4.
RobbieW
Well-known member
A smaller pulley might well do it by running the alternator faster. A couple of questions; is the alternator one of those that are supposedly designed for low speed output and what regulator are you using ?
One thing I'd be concerned about is running the alternator at full output for long periods, it may lead to overheating. I have a Balmar 614 regulator that has both alternator temperature input and a setting to reduce the maximum output. I'm not using that for lithium so the current draw is limited by the batteries needs but running in the Med it used to reduce output when things got a bit hot.
GHA
Well-known member
These ones look OK? Nice price, $436 delivered.
https://sibeile.en.alibaba.com/prod...l?spm=a2700.shop_plgr.41413.25.53e06b1aJhOsqI
https://sibeile.en.alibaba.com/prod...l?spm=a2700.shop_plgr.41413.25.53e06b1aJhOsqI
vas
Well-known member
hm, almost 190Ah useable for 56euro a piece! that's v.good! leaving BMS aside it's Trojan T105 price territory
GHA
Well-known member
Slightly less than I just paid for 2 T105's delivered. Close to clicking that mouse... best of both worlds ?
What about import tax? Into Portugal - anyone know?
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Kelpie
Well-known member
Checking my invoice, I was $438 for 272Ah nominal. Significantly cheaper than Trojans, which would cost me £690 delivered for a set of four.
vas
Well-known member
one of the admittedly few advantages of having a 12V boat vs a 24V one. I need 8 of them :-(
sailaboutvic
Well-known member
What type did you end up buying?
Kelpie
Well-known member
GHA
Well-known member
Is there any import tax involved?
Poey50
Well-known member
Kelpie may be along in a minute to confirm but I believe he slipped through the net and paid no import duty. Ten days ago I ordered something for about 100 Euros from SVB expecting to be hit by UK VAT at least - nothing. Then yesterday I read that the the checks post-Brexit on imported items are in chaos. So [Eastwood voice] GHA are you feeling lucky? Well are you!? [/Eastwood voice]
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Kelpie
Well-known member
So far, that's all I've paid. It was a DDP price so in theory should include everything. If I get a letter from customs I will update the forum!
vas
Well-known member
I recon it's a matter of luck and where you are.
Based in Greece, I've bought numerous things from outside the EU, other small other larger.
A 800quid worth of forged con-rods for a car engine I was rebuilding came clear (4 light conrods in a padded envelope)
A 40USD worth of two Garmin devices (AIS600 and VHF200i I had to pay 30euro customs... (proper carton box)
Things from China arrive with no tax, but again all of them are rather small (and cheap)
Now, I'd expect a 20odd kilo big box of goods will attract some attention from customs!
As I'm planning to make the move for next season, I hope there'll be more options to buy from the EU at a set markup which would be lower than gambling a 300euro customs bill...
Based in Greece, I've bought numerous things from outside the EU, other small other larger.
A 800quid worth of forged con-rods for a car engine I was rebuilding came clear (4 light conrods in a padded envelope)
A 40USD worth of two Garmin devices (AIS600 and VHF200i I had to pay 30euro customs... (proper carton box)
Things from China arrive with no tax, but again all of them are rather small (and cheap)
Now, I'd expect a 20odd kilo big box of goods will attract some attention from customs!
As I'm planning to make the move for next season, I hope there'll be more options to buy from the EU at a set markup which would be lower than gambling a 300euro customs bill...
Kelpie
Well-known member
Started the top balance this evening.
Set my Longwei power supply to 3.65v and turned the current up to max. Checked output voltage with my multimeter, all good.
With the four cells in parallel, I hooked it all up and of course the PSU dipped to the cell voltage of 3.31v.
All looked good, drawing about 4A. But after a few minutes the voltage and current both started climbing, and the current began to rapidly shift around the 7-9A region (this is a 10A PSU).
I saw that the voltage had risen to 4v so I disconnected the power and checked the PSU output again on my meter. It was all over the place, with the voltage up at 4.7v at times.
Is my PSU dodgy? Or am I operating it wrongly? I've dialled back the current and it is now sitting stable at 3.3v/0.54A which I think is not going to harm the cells, but will take an age to charge them.
Set my Longwei power supply to 3.65v and turned the current up to max. Checked output voltage with my multimeter, all good.
With the four cells in parallel, I hooked it all up and of course the PSU dipped to the cell voltage of 3.31v.
All looked good, drawing about 4A. But after a few minutes the voltage and current both started climbing, and the current began to rapidly shift around the 7-9A region (this is a 10A PSU).
I saw that the voltage had risen to 4v so I disconnected the power and checked the PSU output again on my meter. It was all over the place, with the voltage up at 4.7v at times.
Is my PSU dodgy? Or am I operating it wrongly? I've dialled back the current and it is now sitting stable at 3.3v/0.54A which I think is not going to harm the cells, but will take an age to charge them.
Poey50
Well-known member
The method of top balancing I absolutely trust is the one downloadable from this page (orange button, top right corner). Top Balancing LiFePo4 Cells using a low cost benchtop power supply.
The method you used sounds to have conformed to that but do check. I'm assuming you checked the output before attaching to the paralleled cells AND DID NOT TOUCH THE VOLTAGE SETTING THEREAFTER. If followed correctly then it does sound like a faulty PSU since the unit should be limiting the voltage. They seem to be well regarded but nothing is perfect.
Did you do a pre-charge first in 4S configuration?
If the cells are sitting at 3.3 volts with half an amp going into them it will be the next generation of Kelpies that benefits.
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Zing
Well-known member
Something is wrong. 4v+ is too high and 3.31v is too low. I’d cross check those readings with a decent multimeter. Maybe test the PSU on a lead battery.
Kelpie
Well-known member
This is actually the second one of these PSUs that I have had. Am I really that unlucky?
It's now drawing about 0.9A but yes I suppose it's going to take a long time at this rate! I didn't do a charge in 4S, the BMS hasn't arrived yet and I thought it might be a bit risky, but no harm trying the parallel charge straight away.
I thought they would draw more than this but I'll have to read up on that again.
Edit to add: got it up to 4A now, I had a lousy connection with those tiny crocodile clips on to the stud ends- much happier going straight on to the bus bars.
It's now drawing about 0.9A but yes I suppose it's going to take a long time at this rate! I didn't do a charge in 4S, the BMS hasn't arrived yet and I thought it might be a bit risky, but no harm trying the parallel charge straight away.
I thought they would draw more than this but I'll have to read up on that again.
Edit to add: got it up to 4A now, I had a lousy connection with those tiny crocodile clips on to the stud ends- much happier going straight on to the bus bars.
