Lithium batteries

[Art]

"I think the next big evolution will be going to high voltage DC. And I'm not talking about 48V. I'm talking about somewhere in the 100V to 300V range. That would bring current way down, and I think ultimately be much safer, even at the higher voltage."

My fathers boat, former USN WWII subchaser, has a 120+ VDC battery bank.

He uses regular household LED light bulbs for lighting using 120 DC power.
The items that require 120 AC are powered off the invertor, everything else
is 12VDC.

Underway charging is via a shaft generator (not practical for most yachts).

At anchor the boat can go several days without charging as the house load is rather small - no A/C system, etc.

Maybe a 120 VDC system (or bigger) is something to consider...….

Can you post a couple photos of your dad's USN WWII subchaser! That would be cool to see!!

Thanks,

Art

 

[Woodland Hills]

Aren’t most electric cars 480vdc? I’m pretty sure that our BMW i3 was. If so, it would make sense to go to a higher voltage in the future to have some commonality with mass produced batteries, chargers and controllers.

 

[Jon H]

110' LOA, Built in 1943.

 

[JDCAVE]

...Second, they don't like to be hot, and will age faster if operated over about 30C. This means that an engine room is typically not a happy place for LFP batteries. Unfortunately, a lot of boats have their house bank located in the ER, and they would have to be relocated if converting to LFP.

30 degrees C?!?! Thats extraordinarily low! That’s a deal breaker for sure.

Everything in a boat is a compromise. I could probably deal with 40 C, but 30 C is nearly unattainable.

Jim

 

[Art]

30 degrees C?!?! Thats extraordinarily low! That’s a deal breaker for sure.

Everything in a boat is a compromise. I could probably deal with 40 C, but 30 C is nearly unattainable.

Jim

Jim - You may have it backwards. I don't understand your reasoning...

Other post states: "...they don't like to be hot, and will age faster if operated over about 30C".

 

[RTD]

Will Prowse has a web page and u-tube videos which have a very good explanation of lithium battery use and care.
https://www.mobile-solarpower.com/

 

[Nightsky]

Jim - You may have it backwards. I don't understand your reasoning...

Other post states: "...they don't like to be hot, and will age faster if operated over about 30C".

Different manufacturers have different specs. For instance, the Kilovault HLX claims optimal temp range 15-35 deg C, and operational charging range 0-45 C and discharging range -20 to 60 C controlled by internal bms.

 

[stevemitchell]

I'm been powering an off-grid house with LFP (one of the several different li-ion chemistries) for just about a year now. I love them, and would never use lead again for any sort of power system, including on a boat.

For the particular boat you are looking at, the first and most important thing I would check is what chemistry the batteries are. If they are LFP, I would just happily use them. If they are something else, I would probably plan on replacing them, just for safety reasons.

Completely agree with both major points above. I've had LiFePO4 on 3 boats, and at two houses/remote locations. I would never go back to lead given all of the points listed throughout this thread.

Just like with any battery, it is how they were treated that will dictate what real condition they're in, and how long they will last. My current boat had new flooded batteries (only 7 months old) on it when I bought it that had been discharged repeatedly beyond 50% SOC and were in very bad condition.

You could do some testing of the batteries to determine some basic info before purchase, or just budget to replace them sometime soon.

 

[JDCAVE]

Jim - You may have it backwards. I don't understand your reasoning...



Other post states: "...they don't like to be hot, and will age faster if operated over about 30C".

What I meant was it’s a low “upper bound”. I get that they will age faster at higher temperatures but 30 C is not that high.

Jim

 

[Gordon J]

Food for thought on fire flies. This from the manual on temperature:. The optimum operating temperature for a lead-acid battery is 25°C (77°F). As a rule of thumb, every 8-10°C (14-18°F) rise in temperature will cut the battery life in half. Note that continuous duty at elevated temperature will shorten the life of any battery.


So, boat manufacturers ate screwing up by putting banks in engine rooms to start with. How many boaters have batteries elsewhere, not in the engine room? So all that talk about number of cycles is trash for those of us with sub-50 foot boats.

 

[BruceK]

...So, boat manufacturers ate screwing up by putting banks in engine rooms to start with. How many boaters have batteries elsewhere, not in the engine room? So all that talk about number of cycles is trash for those of us with sub-50 foot boats.

Perhaps they are. Though a 36ft boat I`m looking at(not the one which spawned this thread) has 6 conventional SLAs( start, gen.start, thruster/windlass, & 3 house 8Ds)all housed in the lazarette tucked away next to the hull but accessible,3 each side.

 

[O C Diver]

Food for thought on fire flies. This from the manual on temperature:. The optimum operating temperature for a lead-acid battery is 25°C (77°F). As a rule of thumb, every 8-10°C (14-18°F) rise in temperature will cut the battery life in half. Note that continuous duty at elevated temperature will shorten the life of any battery.


So, boat manufacturers ate screwing up by putting banks in engine rooms to start with. How many boaters have batteries elsewhere, not in the engine room? So all that talk about number of cycles is trash for those of us with sub-50 foot boats.

It's never a good idea to use a competitor's misinformation without verifying it. Trojan has their operating temperature range on the T105s listed at -4 to 113 degrees Fahrenheit. The capacity is rated at 82 degrees and increases 10% at 113 degrees.

http://www.trojanbattery.com/pdf/datasheets/T105_Trojan_Data_Sheets.pdf

Ted

 

[Art]

Food for thought on fire flies. This from the manual on temperature:. The optimum operating temperature for a lead-acid battery is 25°C (77°F). As a rule of thumb, every 8-10°C (14-18°F) rise in temperature will cut the battery life in half. Note that continuous duty at elevated temperature will shorten the life of any battery.


So, boat manufacturers ate screwing up by putting banks in engine rooms to start with. How many boaters have batteries elsewhere, not in the engine room? So all that talk about number of cycles is trash for those of us with sub-50 foot boats.

Yes... My 4 FLA deep cycle house bank batts and 1 gen set starter batt are in engine compartment. However, they're not very near engine or genset blocks or heated exhaust areas. I plan to run an outdoor thermometer lead onto top of batt areas in order to actually learn what the air temp is at the batts during different times.

Hope to report outcome on this thread!

Be a while for stats listed; they will include seasonal differences.

 

[Tator]

Food for thought on fire flies. This from the manual on temperature:. The optimum operating temperature for a lead-acid battery is 25°C (77°F). As a rule of thumb, every 8-10°C (14-18°F) rise in temperature will cut the battery life in half. Note that continuous duty at elevated temperature will shorten the life of any battery.


So, boat manufacturers ate screwing up by putting banks in engine rooms to start with. How many boaters have batteries elsewhere, not in the engine room? So all that talk about number of cycles is trash for those of us with sub-50 foot boats.

Must have the wrong 50' boat. On my 40'er I have a bank of 10 t-105s in my master stateroom beneath the floor boards.

Tator

 

[sunchaser]

Must have the wrong 50' boat. On my 40'er I have a bank of 10 t-105s in my master stateroom beneath the floor boards.

Tator

Having non sealed FLAs in the cabin area, especially in the master stateroom, is not recommended. Off gassing is the reason.

 

[twistedtree]

Food for thought on fire flies. This from the manual on temperature:. The optimum operating temperature for a lead-acid battery is 25°C (77°F). As a rule of thumb, every 8-10°C (14-18°F) rise in temperature will cut the battery life in half. Note that continuous duty at elevated temperature will shorten the life of any battery.


So, boat manufacturers ate screwing up by putting banks in engine rooms to start with. How many boaters have batteries elsewhere, not in the engine room? So all that talk about number of cycles is trash for those of us with sub-50 foot boats.

One opportunity that LFP opens up because of their smaller size and weight, is more latitude to locate them elsewhere in the boat. This may help some boats wishing to convert and to get their batteries out of a hot ER.

 

[Tator]

Having non sealed FLAs in the cabin area, especially in the master stateroom, is not recommended. Off gassing is the reason.

The area they are in is as well sealed from the MSR as my engine room is from the salon. In 15 years I have never smelled any gas. They are located in a cooler environment and, more central to chargers, inverters, breakers, buss' and larger power loads.

Tator

 

[sunchaser]

The area they are in is as well sealed from the MSR as my engine room is from the salon. In 15 years I have never smelled any gas. They are located in a cooler environment and, more central to chargers, inverters, breakers, buss' and larger power loads. Tator

Is this well sealed area in your master stateroom ventilated to the outside? The location beneath the floorboards sounds hidden and kind of dicey. BTW, hydrogen gas is odorless.

 

[Gordon J]

Not the same

It's never a good idea to use a competitor's misinformation without verifying it. Trojan has their operating temperature range on the T105s listed at -4 to 113 degrees Fahrenheit. The capacity is rated at 82 degrees and increases 10% at 113 degrees.

http://www.trojanbattery.com/pdf/datasheets/T105_Trojan_Data_Sheets.pdf

Ted

Ted, my fire flies are also rated for a similar temperature band. And capacity does increase with tempetature --- but, the life cycles decrease. I suspect that this also occurs for your batteries. The increase in available output comes at a cost.

I monitor my battery temperature through the charger interface. This fall, while coming down the Atlantic ICW, my typical engine temperature while running was 85f. After shutting down it would go to 95 - 98 or so, for several hours until all that iron cooled.

The batteries would have been better placed under the rear cockpit, but that would have added an additional 20+ feet to the DC cable runs. The engine room is in the center of the boat. I am already using 4/O cables... Hate to think how large they would have had to be if placed in the stern.

Lithium under one of the saloon benches would have been smarter -- from a temperature perspective.


Gordon

 

[O C Diver]

Ted, my fire flies are also rated for a similar temperature band. And capacity does increase with tempetature --- but, the life cycles decrease. I suspect that this also occurs for your batteries. The increase in available output comes at a cost.

I monitor my battery temperature through the charger interface. This fall, while coming down the Atlantic ICW, my typical engine temperature while running was 85f. After shutting down it would go to 95 - 98 or so, for several hours until all that iron cooled.

The batteries would have been better placed under the rear cockpit, but that would have added an additional 20+ feet to the DC cable runs. The engine room is in the center of the boat. I am already using 4/O cables... Hate to think how large they would have had to be if placed in the stern.

Lithium under one of the saloon benches would have been smarter -- from a temperature perspective.


Gordon

Gordon, I had read previously Firefly's shortened life blurb. They would like you to believe through extrapolation that you will loose 75% of your life cycles if your engine room reaches 110 degrees. This just isn't true. There is shortening of cycle life as temperatures above 80 degrees are maintained. For the average cruiser, the elevated hours are a small percentage of the total number of hours in a given year.

I don't exceed a 30% DOD and rarely go below 20%. Trojan implies I should get around 2,500 cycles not counting heat degradation. If I get 840 cycles in 7 years, I'll be ecstatic! That's 120 cycles per year for 7 years. Great value for $800!

Ted

 

[Art]

I watched entire "Choose the best battery for your boat" video with Jeff Cote.

Good video - I have this question:

Per month, how much percent of their charge-level do you feel an isolated Flooded Lead Acid battery loses?

Jeff mentioned that Flooded Lead Acid batteries lose 15% of their charge per month. I've previously heard that 5% is their loss.

12/22/19 on my post #22 [quoted above]... I mentioned not understanding Jeff Cote's statement: "Flooded Lead Acid batteries lose 15% of their charge per month". I also mentioned in that post: "I've previously heard that 5% is their loss."

Well... Due to reasons we'd not been able to visit our fun boat for a while.

So... this past weekend we visited our Tollycraft after exactly four [4] months time lapse [to the day - per the log]. As always, when first aboard I immediately checked the multimeter I have hooked into our boat's four [4], #31, hooked in parallel, deep cycle, FLA house bank batts. The bank had lost approximately 20% of its charge; therefore it was discharged down to approximately 80% of a total charge.

Therefore... having officially [read by a high end multi meter] lost 20% charge in exactly four months means that my lifelong understanding of an average 5% charge-loss per month for previously 100% charged, good condition, totally isolated, FLA batts is reality. Not 15% per month.

Batts in house bank are about 1 yr old. Same exact type/size of batts I replaced were from 2010; they were still functioning, but with reduced power retention capability. The old batts in house bank also dropped approx 5% charge per month. All batts in boat are deep in bilge with surrounding water temp from 74 F in summer to 60 F in winter. I do not know what batt temp averages throughout the seasons. Will say that even in summer the bilge area does not get very hot... this I know, by often entering engine compartment throughout the year when aboard.

We always leave all batts 100% charged and 100% isolated... except for bilge pump float switch. We also isolate the boat from the berth with four docking lines and from dock power... for limited metal corrosion.

Must admit we do have a trickle charge solar panel on flying bridge face for making sure the genset battery can never go dead while we're out and about in the water. That said, the solar panel does us no good under roof at covered dock we've kept our Tolly in since April, 2009.