LiTime 12v 230ah LFP $469

[dhays]

Is that thruster rating peak amps or continuous? Large thrusters are tough. It will be fine for my little windlass though.

I have a 500 amp carbon pile load tester along with an inverter. Ill get that carbon pile tester smoking and see how long it can take 500-600 amps.

The only information I was able to see for the Vetus was 650amp. It is a 14 year old thruster. Their current 95kg thrusters much be more efficient as they say that it is 610 amps.

 

[Barking Sands]

The only information I was able to see for the Vetus was 650amp. It is a 14 year old thruster. Their current 95kg thrusters much be more efficient as they say that it is 610 amps.

LOL...5.7KW. That's quite a bit any way you dice it!

 

[mvweebles]

"This function is only tested under the condition of soc>60%@25℃. Even so, frequent high-rated discharge will still have an impact on the life of the battery. If this peak current is output frequently, damage may even occur.".

Wow! Using a battery within the specs is not recommended. Well that certainly changes the use case recommendation!

Will Prowse's most recent review is of the Ecoflow 12v 100AH trolling battery ($220). He tests the hi-discharge claim of 300a for 30-secs which it does indeed deliver. He of course has no way to tell whether repeated high discharge use would damage the battery.

My thruster is protected by a 400a fuse. Under normal usage, it draws under 300a. I know this because last year my anchor was hopelessly fouled on a rock. I tried maneuvering the bow around using the prolonged thruster and it eventually tripped the fuse which I later discovered was a 300a fuse, not the specified 400a fuse.

At any rate, batteries designed for trolling motors seem to have slightly different BMSs.

Peter

 

[Barking Sands]

Wow! Using a battery within the specs is not recommended. Well that certainly changes the use case recommendation!

Will Prowse's most recent review is of the Ecoflow 12v 100AH trolling battery ($220). He tests the hi-discharge claim of 300a for 30-secs which it does indeed deliver. He of course has no way to tell whether repeated high discharge use would damage the battery.

Peter

I think they are just warning that hitting peaks every time will lower life expectancy. I think this is true of all Lifepo4 batts pushing large amps. I have been reading other "crazy" forums were its common to use no BMS on lifepo4 cells for windlass and thrusters. The cells themselves will do it, but at a cost to their longevity. And of course if a BMS is put inline it needs to have that amp load capability. I think this warning is just being honest that hammering these to peak every cycle comes at a cost. Like anything it would be best to leave some wiggle room. But it can do it.

I just did some testing on the little 120ah version. It can give 500 honest amps for 25 seconds. I think I was losing a bit on amps on my poor alligator clips on the terminal too. They got pretty hot. This was measured with a DC clamp amp meter on the wires so the heat loss at the alligator clips was not accounted for and I did not have a chance to read the app, which would have accounted for the heat loss too. Ill be doing a few more timed tests at various amp loads to plot it out. But a pair of these looks like 1000 amps for 25 seconds or less will work.

 

[dhays]

I think they are just warning that hitting peaks every time will lower life expectancy. I think this is true of all Lifepo4 batts pushing large amps. I have been reading other "crazy" forums were its common to use no BMS on lifepo4 cells for windlass and thrusters. The cells themselves will do it, but at a cost to their longevity. And of course if a BMS is put inline it needs to have that amp load capability. I think this warning is just being honest that hammering these to peak every cycle comes at a cost. Like anything it would be best to leave some wiggle room. But it can do it.

I just did some testing on the little 120ah version. It can give 500 honest amps for 25 seconds. I think I was losing a bit on amps on my poor alligator clips on the terminal too. They got pretty hot. This was measured with a DC clamp amp meter on the wires so the heat loss at the alligator clips was not accounted for and I did not have a chance to read the app, which would have accounted for the heat loss too. Ill be doing a few more timed tests at various amp loads to plot it out. But a pair of these looks like 1000 amps for 25 seconds or less will work.

Yeah, if one battery can do 500amps for 25 seconds, two of those could likely handle my thrusters without a problem. If I recall these are a Group 27 size so two of them would have the same footprint as an 8D.

 

[Barking Sands]

Yeah, if one battery can do 500amps for 25 seconds, two of those could likely handle my thrusters without a problem. If I recall these are a Group 27 size so two of them would have the same footprint as an 8D.

Maybe..its still cutting it close on a timeline. I guess 25 seconds is quite a bit. But each subsequent bump may reduce the next bumps time. Ill check that too. Like, how many 500 amp 20 second bumps can it do in a row separated by 20 seconds?

And then there is cost. The ones Peter linked to did an honest 300 amps for 30 seconds. You could get 3 of those. However it looks like those dont have bluetooth or any way to determine SOC..as I would assume that Epochs detailed discharge rating based on SOC would probably apply to any Lifepo4 batts. SO not knowing SOC may be a problem on occasion. You could add a shunt for SOC tracking.

Epoch is coming out with a comm box for the 120 and 300 dual purpose that may have an NMEA output. That would be REALLY nice to plumb these into a plotter so you could easily check SOC prior to deploying the thruster or Windlass.

Any way you cut...there are so many options and possible configurations its hard to make a choice...lol. And the options grow every day and a costs keep dropping.