Trying to understand the lack of low temp sensor for my application. I run a boat with an electric motor in 36v configuration. The use case is often in very cold water (Michigan and fishing this time of year). We fish right up until the lakes freeze over. Often times fishing in air temps below freezing. Could I use the Amphere time 12v 100ah batts wired in series for 36v as long as I stayed above freezing for charging? I keep this boat in a heated garage and would wait until home before charging. Thanks for any insight.
Amphere Time
- Thread starter Tm7554
- Start date
sunshine_eggo
Happy Breffast!
Most LFP batteries permit discharge down to -20°C (-4°F).
Would confirm the motor SURGE rating does not exceed the 100A limit of the BMS.
Would be concerned that the batteries are actually above freezing before you start charging. Would want something like a Victron SmartShunt with a temperature sensor on the battery or a Victron smart battery sense to confirm the battery is 40°F or above. It's the INSIDE temp of the battery that matters way more than the outside temp.
Would confirm the motor SURGE rating does not exceed the 100A limit of the BMS.
Would be concerned that the batteries are actually above freezing before you start charging. Would want something like a Victron SmartShunt with a temperature sensor on the battery or a Victron smart battery sense to confirm the battery is 40°F or above. It's the INSIDE temp of the battery that matters way more than the outside temp.
I follow most of that and thanks.
Maybe I should be asking for what the best deal is on marine lithium batts with a bad with a low temp sensor?
sunshine_eggo
Happy Breffast!
The first question is will your electric motor overload the current limitations on the BMS of the batteries. Most 12V LFP CELLS can handle more current than the battery can. The restriction is almost always the BMS managing the cells.
What is the surge current on your motor?
What is the surge current on your motor?
eXodus
Solar Addict
- Joined
- Jul 27, 2020
- Messages
- 1,482
Is the electric motor your only engine? Or is this just an additional?
I wouldn't want to have a low temp disconnect in a boat when my life depends on it. It will disconnect your power.
So you either get a battery which can handle that or stay with lead. AGM or so for low temp.
I wouldn't want to have a low temp disconnect in a boat when my life depends on it. It will disconnect your power.
So you either get a battery which can handle that or stay with lead. AGM or so for low temp.
Cajunwolf
Solar Enthusiast
I was thinking the same thing. I used to sail. That being said, they have battery heaters that may or may not draw too much of your available power, just a thought.
Cajunwolf
Solar Enthusiast
If it were me, I'd do it, just tie the batteries down good are you'll be okay. Dang, I've run big crew boats offshore in the Gulf of Mexico back in the days when we hunted dinosaurs for food and had to crawl around the engine room up to my ass in saltwater to try and get the darn bilge pump running, so I didn't sink. I never thought about the bank of monster-sized 12-volt batteries that were entirely under the water, configured to 24-volts in order to crank Two 16v92 diesel engines. I'm still here today near 60 years later to tell about it. I just bought 4 chins 12-volt 200ah batteries for $2400, do the math, that's a deal. If you're worried about the temperature they have battery heaters or rig something.
