A lithium battery question.

[Comodave]

Where would I find Rod Collins review you mentioned?
I am doing a new build of a boat and thinking of using LFP batteries.

HRK

Marinehowto.com. Great resource.

 

[dannc]

Where would I find Rod Collins review you mentioned?
I am doing a new build of a boat and thinking of using LFP batteries.

HRK

Here is a link the Rod wrote years ago regarding LiFePO batteries but is still relevant, https://marinehowto.com/lifepo4-batteries-on-boats/.

The link posted earlier in the discussion, is about drop in replacement LiFePo batteries, which you would not want on a new build, but the article is well worth a read anyway.

Rod's website is a treasure trove of information, especially for electrical subjects regarding boats.

If you are doing a new build, I would also suggest looking at the Professional Boat Builder(PBO) magazine and website, https://www.proboat.com/.

Then there is Steve's website, https://stevedmarineconsulting.com/. His website has at least some of his articles that have been published in PBO.

Michael Kasten, a boat designer and long time editor of the Metal Boat Society magazine, has interesting articles on boat designs on his website, Articles on Yacht Design and Boat Building.

The Dashew's website is also a treasure trove of boat design and build information, https://setsail.com/history/. The Dashew's have also released their four books in a PDF format for free. Some of the information is now dated but much is still valid, https://setsail.com/free-books/. Their Offshore Cruising Encyclopedia(OCE) is one book that can be dated because technology has changed but there is much to be learned in the book. There are sections in the OCE on building a new boat, dealing with builders, contracts, etc., that might be of interest.

Later,
Dan

 

[gunho1]

Battleborn

Great company, fabulous customer service

https://battlebornbatteries.com/

 

[DDW]

I'm going to guess that the 300 amp spec is at 48v. At 12v that would be 1200 amps.

I'd guess not. 300A @48V would be 14 Kw or about 20 hp. But it will likely say on the motors.

 

[Jeff F]

I'd guess not. 300A @48V would be 14 Kw or about 20 hp. But it will likely say on the motors.

300 amps at 12v is less than 5 hp. Most thrusters on 48 ft boats are considerably larger than that. My 7.5 HP 12v bow thruster specifies 650 amps, and my 7.5 HP 24v stern thruster specifies 325 amps. Based on those numbers, 15 HP would be 325 amps @ 48v.

It seems unlikely that the OP's thruster is only 3.6 kw, and hence the 300 amps @ 12v spec doesn't pass the sniff test

 

[DDW]

Well, 300A x 48V is 14.4Kw, which is 19.3 Hp input. Lewmar and Vetus both seem to think 5 - 8 hp is good for a 45'. Vetus specifies 20 hp + for 72'+ boats, Lewmar thinks 15 is good for an 80'. But the point is, before he buys batteries, he should look on the motor and see what it really wants. Could be the builder overkilled it - why go to 48V otherwise? While I'm asking questions, why a 48V thruster on a 12V boat?