Bow thruster battery

[JulianG]

Have now installed a battery to battrey charger 40a. So now have 3 x 280ah lifepo4 batteries in paralell. Which I use with the bow thruster and anchor winch pulling 170a on the thruster. I have 3 x 110 ah starter batteries slight over kill but possible back up. Having used the sterling alt to batt charger for over a year on lithium setting with no problem am going to see which works better. I have only ever run the batteries down to 50%. My alternater is a 100amp never over heats, but I do have an alt saver attached just in case a fuse blows but I have never seen an issue.

Next move may be to use an additional lifepo4 as a starter battery but how will I charge it ??? What dammage will occour ?
Pulling high amps from a lifepo4 for a matter of seconds will this degrade the battery and to what extent.

My engine is a 55HP Nanni diesel.

 

[Goboatingnow]

I’ve read the posts and have seen the concerns for using lifepo4 batteries to power a bow thruster. I have a smaller thruster that is rated at 200A cont. When I use it, it pulls my LA battery voltage down enough to stall the engine.

My plan is to build a 12v pack out of 8 EVE 280AH cells, which I‘m getting ready to order from Jenny Wu. I haven’t started looking at a BMS solution yet. I know some of the options could be one large BMS with external contactors, or maybe use two BMS and make two individual packs in order to split the current between each pack.

Have any of you had success powering the bow thruster and windlass from a lifepo4 pack and if so, do you have any pointers?

P.S. if this doesn’t work, I’ll have a large enough house battery that I can run without the generator for most of the day.

Li batteries of a proper size and type have no issue with bow thrusters LFP can have C limitation but 2-3C batteries are available