Garmin Gear and Lithium 24v Questions

[Lovey80]

That's a nicely set up boat but I still don't understand how a dc converter rated to 50a will work with a electric motor that at 100% power will draw 56a?

It's easy to say you won't ever use 100% power but what's stopping the electric motor hitting max power when spot locking in a high wind/current? And what happens to the converter when this happens?

Does it reset straight away once the current draw is below 50a? Or if you use a 50a resettable breaker to limit current draw (as you should) that is going to be a big PITA if you have to go reset it when it trips out.

https://trollingmotorpro.com/trollin...mp-draw-chart/

I spoke to Trolltek about this last week and they told me to not use the converter and to go with a seperate 24v battery for the electric motor. They couldn't tell me what the over current limit was in their units.

Maybe I need to talk to Revolution or Victron to see if they can supply any more information on their converters and whether they are suitable.

I’m not 100% on this but I’d imagine that the 50A is the continuous rating. Like most of these types of items they have that rating as a safe working range, but have an ability to run for shorter periods a bit above that. Just like most inverters out there, say a 2000w inverter will run 2000w continuous but will give you 2100-2200w for short periods. The spot lock spiking to 56A for a few seconds wouldn’t worry it. But run on 10 and try to troll around at full tilt for a few hours is going to create a lot of heat in the converter and it will probably refuse to put out a full 56A. Effectively de-rating itself. Also I imagine they give the 50a @24v or 36v rating coming from a stock standard 12.8v battery. Your lithium will rarely get to 12.8v and will live 90% of its range over 13.2v. If that gives a margin of error I’m not sure.

Your breaker will be 60A. Even that won’t trip unless you maintain above 60A or spike well above it, like in rough seas when the prop may come out of the water and spins up before hitting back into the water.

[marto78]

I found this data sheet on the victron website

[Lovey80]

That's the 24-12v step down DC-DC charger/converter right?

I looked heavily at going 36v and stepping down to 12v for the rest of the electrical system. While I've delayed doing the install, I decided the on-board charging of the system to be the most important to me and the Victron/RedArc DC-DC charging system for lithium is where I wanted to go. When I saw others using the 12-36v converters without issue, I decided that was for me.

[marto78]

The column on the far right is for the Revolution 12v to 24v converter, they're made by Victron/Orion. I don't know who makes their 36v one.

I'll be interested to see how your set up goes. Hopefully 80lb of thrust out of the Kraken will be enough for my boat. It would be good to find a 24v to 36v converter to get 100lb of thrust out of it.

[Lovey80]

The column on the far right is for the Revolution 12v to 24v converter, they're made by Victron/Orion. I don't know who makes their 36v one.

I'll be interested to see how your set up goes. Hopefully 80lb of thrust out of the Kraken will be enough for my boat. It would be good to find a 24v to 36v converter to get 100lb of thrust out of it.

Have you already bought the 24v battery? Why not keep everything 12v for easy charging and just get the 12-36v converter for the Kraken?

[marto78]

I've already ordered a 24v 100ah battery, I'm just kicking myself I didn't see the 200ah 24v battery for $2200 when I placed the order.