Batteries in the engine room

[dawnthreader]

Hi

I am considering changing the house bank of my boat to a Lifepo4 battery.
Options include Winston and the some of the 280 ah aluminum case batteries that are slightly cheaper. (let's call them EVE)

The EVE batteries have a form factor that better fits my boat - but the Winston cells would work.

The battery bank (currently 3 AGM 100ah) is located in the engine room (not ideal - but boats are full of compromises) and shares the space with 2 diesel engines.
When the engines are running (this is a recreational boat so 50-100 hours per year) there are lots of vibrations.
While running the airflow is very high so the engine room does not get hot - but when the engines are turned off the temperature rises for a while.

What do you think of these physical conditions?
can they be handled by the aluminum cased EVE cells or am i better of getting the sturdier Winston cells?

btw i am planning to use this BMS which seems to be quite unheard of (it has a nice capability of regulating the alternators to avoid overheating / overcharging)

 

[newbostonconst]

I think the mass of the battery will get it through the temp increase if it is only hot on shutdown. Is there room in your holder to slide some foam on some of the sides of the cells to slow down the heat getting to them.

You might also place a jug of water of similar size to the batteries near where the batteries are going to be with a thermometer in it to see the temp rise after you have ran the batteries.

 

[magnesium]

btw i am planning to use this BMS which seems to be quite unheard of (it has a nice capability of regulating the alternators to avoid overheating / overcharging)

I love the fuse used in those drawings... It MUST be Class T fuse for safety and fire security in case of a blowing fuse.
For the BMS, no idea about this brand, I prefer 123SmartBMS or equivalent.
About LFP batteries, your are speaking with two different chemistry, Winston use Yttrium in those specifics cells, they make it fully compatible as lead battery (AGM) replacement on voltage and temp range (not in capacity or DOD and not when charging with an alternator), the EVE like are only LiFePO4 cells, more sensitive about temperature. If you carefully top balance the Winston cells, you can use them without BMS if you never charge or discharge over 0.2C.
I'm more (very) confident with Winston... I use this cells for a long time without problems, even after some low discharge to 2.5V/cell...
What's about aluminum case of EVE cells in marine environment ?
About LFP, If you have vibrations, you must use cells under 200Ah capacity because the more the cells are wider or larger, the more the pouchs inside cells can move and may having problems and getting deformed over time. And you must try to avoid or isolate cells from engine vibrations as more as you can do.
I've discussed with a tech engineer from Sinopoly about boats and specially sailboats, they do not recommend higher capacity of 200Ah and you must paid attention to firmly block each sides of the battery pack to avoid deformation. If you need more than 200Ah, use 4S2P.
About temperature, you should check engine compartment after a run, then check temperature characteristics of the cells you want to choose and /or keep the airflow for a moment to decrease temperature to a correct level for the cells. EVE cells are 60°C max (Chinese temp ?), Winston Yttrium are 65°C, also Chinese, but more reliable and renowned and "max continuous operating temp" in the data sheet ...

 

[Shinebox]

Depends on the engine room/space I suppose. If it’s large enough and has enough active cooling, sure. On a smaller sailboat with a smaller space that gets very hot, no.

 

[Alloy]

A temperature logger in the ER will tell what the temp is.
Is there mechanical ventilation?

 

[dawnthreader]

A temperature logger in the ER will tell what the temp is.
Is there mechanical ventilation?

When the engines are running there is lots of mechanical ventilation

 

[mitiempo]

What about after the engine is shut down? That is when the heat builds without the blower running.

 

[time2roll]

What about after the engine is shut down? That is when the heat builds without the blower running.

Need a delay module to keep a blower running.

 

[dawnthreader]

I've now been running with my winston lifepo4 setup for one season - and there is no problem with the batteries getting warm. The highest temperature the bms has registered so far is 30 degrees celsius...

 

[wholybee]

If they are well mounted in a simple compression frame so they can't move, either should deal with the conditions fine. Higher temps will reduce life, but they will still last a long time, and may still outlast your ownership of the boat. The Winston is a better battery. But more important than Winston vs. Whatever, is where you buy them, and where they come from. There are a lot of "grade a" cells that are highly questionable and don't perform well at all. You get what you pay for, so don't shop for the cheapest cell.

That BMS is very intriguing, but I know nothing about it specifically. It checks a lot of boxes, seems to be ABYC compliant, and isn't grossly overpriced for what it is. The question really comes down to how reliable it is and the build quality. I'd look at is closely but cautiously.

Magnesium recommends the 123SmartBMS, and I am going to vote strongly against that particular BMS. I helped a friend sort his Lithium issues, and that BMS was all sorts of problems. It's truly awful.

BMS's that are known to be of high quality and highly recommended are the REC, Orion, and Tao. All pretty expensive but check all the boxes. Reasonably priced and popular are Daly and Overkill (JBD). However, they don't check all the boxes, and there isn't agreement on their recommendation.

To plan what BMS you need, you need to consider what current draw you will have (just basic instruments and VHF, or will you have an electric galley) charge current, and will your alternator be charging the LiFePO4.

 

[Skypower]

Large Lifepo4 cells that are in a box that only have limited air contact(top only- no air gap between them) tend to gain or loose heat very slowly from ambient surroundings. A typical day cruise won’t have as much affect on battery temperature in a normal marine engine room. Consecutive days where nights time temperatures don’t drop may became an issue and need monitoring. I’ve seen a highly successful enclosed Lifepo4 battery box with a surprisingly small thermoelectric(Peltier) cooling for an application in the UAE. I’ve found balsa or foam core hull boats engine rooms tend to be hotter because the hull doesn’t have as much cooling effect. Proper dynamic and powered air circulation (blower) should keep temperatures in check.

 

[mitiempo]

To plan what BMS you need, you need to consider what current draw you will have (just basic instruments and VHF, or will you have an electric galley) charge current, and will your alternator be charging the LiFePO4.

That depends which BMS you choose. With a Daly or Overkill you are correct. The Electrodacus I have and some others are not current limited at all.

 

[wholybee]

That depends which BMS you choose. With a Daly or Overkill you are correct. The Electrodacus I have and some others are not current limited at all.

Aren't you basically just saying the same thing? If you need a lot of current, choose a bms with a contactor. But you need to know your current draw before making that decision.

 

[mitiempo]

What I am saying is that most makes of BMS like Daly and Overkill have the current in and out of the bank going through the BMS. Others like the Electrodacus do not have system current going through the BMS so system current in or out is not relevant.

 

[wholybee]

What I am saying is that most makes of BMS like Daly and Overkill have the current in and out of the bank going through the BMS. Others like the Electrodacus do not have system current going through the BMS so system current in or out is not relevant.

I get that. But in a given boat, in fact many boats, there may not be a need for more than 30A (a typical dcdc charger to the start battery) So instead of spending extra money on a a more complicated electodaucus, you can choose something else. That's why you evaluate your needs first, then select a BMS.

I also named 3 BMS's that like the Electodaucus use contactors with no theoretical limit. But for some people a daly or overkill is a better choice.

 

[mitiempo]

i've installed Overkill on several systems and Electodacus on my own system. They all have their applications. On a system with windlass and inverter the Electrodacus makes more sense with the higher loads.

 

[manly]

@whollybee, you wrote:

BMS's that are known to be of high quality and highly recommended are the REC, Orion, and Tao. All pretty expensive but check all the boxes. Reasonably priced and popular are Daly and Overkill (JBD). However, they don't check all the boxes, and there isn't agreement on their recommendation.

What boxes do the Overkill not check? That's the BMS I'm planning to use in my marine installation. Thanks!

 

[wholybee]

The big one is that the overkill solar does not provide an alarm or notification warning before a disconnect occurs. This is required to be ABYC compliant, and thus many insurance companies require it as well. No reasonably priced bms has this feature. My personal opinion is that its not important unless your insurance required it.
The expensive units like rec also can control an alternator, shutting it off before a disconnect.

 

[manly]

@wholybee, my current battleborn batteries do not have any alarm or notifiaction warning (to my knowledge) before disconnecting. Perhaps they are not ABC compliant either.

I agree with your opinion that feature is not too important. I won't have my alternator hooked up to the lifepo4 pack, so an unexpected disconnect shouldn't hurt much.

 

[Skypower]

Pretty much the last place I’d be using Lifepo4 batteries is for start/run/ignition for engine or generator. For “house” or inverter bank, absolutely I would consider them after making allowances for their unique requirements. Battleborn make very safe, reliable batteries and markets for marine. They are amongst the most expensive yet have no apps or connectivity as far as I know.