Can you suggest a good setup for a 12v and 48v DIY battery off alibaba/eBay?

[MarinerBlue]

Hello everyone,

I have a C&C 30 sailboat that currently has a gasoline engine that I will be converting to electric in 2021. I have no experience with batteries, solar panels, and electric motors, so I am trying to do this in a gradual way and spread out my learning along the way. I have decided that the first step for me will be to build my own battery and replace the current battery on the boat with 12v LiFePO4. Are there any good samaritans on this board who can suggest an economical set up if components off of Alibaba or eBay? I could go for 50 to 100 Ah for this component. If I could reuse the same parts for a 48v 300ah battery during the next step, that would be a plus. The boat is located in Canada, so cold-weather protection would be a plus. Thanks!

 

[HRTKD]

For keeping the LiFePO4 batteries warm, here's is how I did it: https://diysolarforum.com/threads/lifepo4-battery-warmer-install.14485/

 

[Just John]

Hello everyone,

I have a C&C 30 sailboat that currently has a gasoline engine that I will be converting to electric in 2021. I have no experience with batteries, solar panels, and electric motors, so I am trying to do this in a gradual way and spread out my learning along the way. I have decided that the first step for me will be to build my own battery and replace the current battery on the boat with 12v LiFePO4. Are there any good samaritans on this board who can suggest an economical set up if components off of Alibaba or eBay? I could go for 50 to 100 Ah for this component. If I could reuse the same parts for a 48v 300ah battery during the next step, that would be a plus. The boat is located in Canada, so cold-weather protection would be a plus. Thanks!

Really depends on your requirements. That said, Overkill Solar has some very beginner friendly stuff. Didn't notice anything on the site about heating, just low temperature charging disconnect that does work. I have seen other threads on here on the topic that had some interesting ideas, but personally, living in the desert, heating batteries is not a problem for me.

 

[MarinerBlue]

Really depends on your requirements. That said, Overkill Solar has some very beginner friendly stuff. Didn't notice anything on the site about heating, just low temperature charging disconnect that does work. I have seen other threads on here on the topic that had some interesting ideas, but personally, living in the desert, heating batteries is not a problem for me.

Overkill solar sounds perfect.

 

[HRTKD]

I use the Overkill Solar BMS devices. I have one on each of my 4s 12v LiFePO4 batteries.

The thread to get you to a reputable source for LiFePO4 cells is this: https://diysolarforum.com/threads/i...ed-shenzhen-luyuan-technology-co.15880/unread

I used Amy when she was at a different company (Xuba). I wouldn't hesitate to use her at the new company.

If the cabin of your boat will be heated all the time, then the batteries will be warm and you don't need to worry about a heating system. If the cabin will not be heated and left unattended, you have a couple options. First, remove that batteries when you're not there. Second, a warming system like I suggested in my prior post.

With regard to reusing 12v parts, I'm sceptical about that. Ideally, you want all the cells to be as close to the same as you can get. A set of four out of sixteen cells that have been in use for a year aren't likely to match the performance of the other twelve cells. You might be better off buying 16 cells now, creating four 4s 12v batteries and running them until you're ready to switch to 48v. In that case, taking all sixteen cells and making a single 16s battery would work. You would still top balance the 16 cells a second time.

Have you watched the Will Prowse videos on YouTube? If not, that's a great place to start. Pick and choose the videos that interest you and are at the level you need. The battery teardown videos probably aren't what you're looking for, but they make for some good entertainment.

 

[JoeHam]

And cold for LiFePO4 is generally below freezing and the water is very hard to sail through at that point ?

Do you winter on the hard or bubble? If not staying aboard in winter and charging then it won’t be a problem.

Here on the south shore of Lake Erie I don’t do any winter boating!

 

[Just John]

The thread to get you to a reputable source for LiFePO4 cells is this: https://diysolarforum.com/threads/i...ed-shenzhen-luyuan-technology-co.15880/unread

I used Amy when she was at a different company (Xuba). I wouldn't hesitate to use her at the new company.

I agree and also had a similar experience dealing with Amy. I wouldn't hesitate to deal with her again.

 

[Love.Sun]

Is it a good idea to get LiFePO4 cells from the alibaba and such sites?
Aren't there risks of getting fake stuff? I am still a beginner so I am asking..

 

[Ampster]

Is it a good idea to get LiFePO4 cells from the alibaba and such sites?
Aren't there risks of getting fake stuff? I am still a beginner so I am asking..

Like you I was sceptical. There are risks and I did several things to reduce the risk to an acceptable level. I spent several weeks reading threads and learning how to make sure there was no risk of customs fees by specifying DDR. I also discovered a pattern of transactions that went smoothly. Finally, I made my decision and paid by credit card which put the credit card company on my side if something went long with the delivery. I had already derisked the issue of the quality of the cells by reading the forum and having realistic expectations. I did order some spares and including the spares I still feel I have received significant value. In total I will have purchased 52 cells, of which 48 will be in a pack and 4 are spares. The spares are not idle, they are in a pack that I have used to keep the refrigerator running at my sisters house during a power outage.

 

[Love.Sun]

Like you I was sceptical. There are risks and I did several things to reduce the risk to an acceptable level. I spent several weeks reading threads and learning how to make sure there was no risk of customs fees by specifying DDR. I also discovered a pattern of transactions that went smoothly. Finally, I made my decision and paid by credit card which put the credit card company on my side if something went long with the delivery. I had already derisked the issue of the quality of the cells by reading the forum and having realistic expectations. I did order some spares and including the spares I still feel I have received significant value. In total I will have purchased 52 cells, of which 48 will be in a pack and 4 are spares. The spares are not idle, they are in a pack that I have used to keep the refrigerator running at my sisters house during a power outage.

Sounds like you did a great job protecting your investment and making sure you get what you needed.
But since I am new to this. I have one further question. Do people buy on alibaba because it is cheaper or? I am wondering are there US based sellers and if there are, do they source from alibaba too? I am guessing that they do and you are basically buying a reassurance as they did the hard job of making sure all is well with the batteries

 

[rin67630]

... the water is very hard to sail through at that point ?

...not on oceans.

 

[Ampster]

I am wondering are there US based sellers and if there are, do they source from alibaba too?

Yes it is the price. I dont know if these cells have distributors. In the past I have puchase from distributors of Winston and CALB at significantly higher prices. There are group buys that you can search for here.

 

[Love.Sun]

Yes it is the price. I dont know if these cells have distributors. In the past I have puchase from distributors of Winston and CALB at significantly higher prices. There are group buys that you can search for here.

Interesting! Thanks for sharing my friend!

 

[MarinerBlue]

Like you I was sceptical. There are risks and I did several things to reduce the risk to an acceptable level. I spent several weeks reading threads and learning how to make sure there was no risk of customs fees by specifying DDR. I also discovered a pattern of transactions that went smoothly. Finally, I made my decision and paid by credit card which put the credit card company on my side if something went long with the delivery. I had already derisked the issue of the quality of the cells by reading the forum and having realistic expectations. I did order some spares and including the spares I still feel I have received significant value. In total I will have purchased 52 cells, of which 48 will be in a pack and 4 are spares. The spares are not idle, they are in a pack that I have used to keep the refrigerator running at my sisters house during a power outage.

Thanks for the tips. Could you clarify what DDR means?

 

[Just John]

Thanks for the tips. Could you clarify what DDR means?

Delivery Duty Paid (DDP) Pretty sure that DDR is a typo, unless it is computer memory.

It is actually an outdated term that is still in widespread use:

• 
  Delivered duty paid (DDP) is a delivery agreement whereby the seller assumes all responsibility of transporting the goods until they reach an agreed-upon destination.
• The seller must arrange for all transportation and associated costs including export clearance and customs documentation required to reach the destination port.
• The risks to the seller are broad and include VAT charges, bribery, and storage costs if unexpected delays occur.
• A DDP benefits a buyer as the seller assumes most of the liability and costs for shipping.

Difference between DDP and DDU terms of delivery

 

[Ampster]

Pretty sure that DDR is a typo, unless it is computer memory.

Yes it is a typo. Should have been DDP.