6BTA Starting battery

[Carl Almond]

I currently have two group 27 lead-acid starting batteries per motor. I would like to reduce weight and save space and so am considering a single 12V 100AH Lithium Ion Battery (link below).

https://www.lithiumion-batteries.com/products/12-volt-lithium-batteries/chargex-12v-100ah-lithium-battery.php

After chatting with the engineers at Chargex they believe the above battery will have plenty of power to start the 6BTA motor and will work well with my current battery charger and alternator.

Has anyone converted to Lithium-Ion as a starting battery and if so what was your experience?

4 X 27M6 batteries = 230#s

2 X LI batteries = 62#s

Savings = 168#s

And when I get around to the house and thruster batteries I will save another 168#s for a total of 336#s and that is a whole lot of beer (~438 cans)!!!

Topic

[Paul Vlug]

Maxwell 1800 cca capacitor

I now use a Maxwell 1800 cca capacitor to spin the starter motor on my qsb 6.7, even the Cummins tech who did the commissioning likes the setup. The 200amp alternator is connected to 400 amp hour lithium batteries. The Maxwell is about 14 lbs the lithium weight is less then half of what lead acid batteries with 4 times the useable capacity.

[Stephen Oliver]

I use 1 group 31 (i think or the Aus equivalent) Bosch S4 batteries rated at 1100cca so within 6bta spec per engine. 

If you want to save weight.. what are you using as a house bank? I just replaced 175kg of lead with 28kg of Lifepo4 and have more total capacity. <br /><br />Re lithium for starting, its specialist and they need huge BMS’s to deal with current. They will also no doubt burn your altenator out unless you have external regulation with lithium profile and limiting of current. Lithium will suck up all they can.. example my BMS is 250a and i can charge to 250 with no issues. The batteries will charge at 1c (326amps) happily so i could easily burn my alternators out even though they are 105a each.. hence i have DC2DC chargers in between the alternator and lithium (via the crank battery)

Steve

 

 

[Carl Almond]

I had trouble finding the Deka brand but it looks like East Penn who makes Deka also makes many of the Napa house brand lead-acid batteries which I can get. Comparing specifications and battery cases the Deka 1231PMF and the Napa BAT 7234 are essentially the same battery. I have 2 on order and will be shaving 103#s off my battery weight.

I am going to hold off on the house batteries for a year or two since they are new and I might as well get my money out of them. Eventually, I will remove the 4 AGM (266#s) and replace them with 4 LI (124#s) and save another 142#s.

That will bring me to 245#s I can safely redistribute to beer and not exceed the neighborhood lift capacity. 😊 I appreciate everyone’s help on this idea as it has helped me save money and still meet my weight reduction goals!

[Carl Almond]

I just posted a new topic and the forum did not go psycho on me so I will give this another try. I also wrote the other post in Notepad and then pasted it into the forum window so if the forum goes full-on psycho I can just re-paste it… Tony, As I mentioned in our phone calls, I live on a freshwater lake and have to pick my boat up using a lift similar to a travel lift and move it to the saltwater and back when I return. What I did not mention was that our lifts are rated by the manufacturer at 30,000 pounds and the neighborhood decided to de rate them to 25,000 pounds. According to two separate boat yards my boat weighed in at 22,000 pounds (10K front sling and 12K back sling) and in both cases, the boat was not fully loaded. As such I am very weight conscious and take weight out of the boat every chance I get so that when I need to add some weight I do not get to the point where I am accidentally overweight for the neighborhood lift ratings. I agree with you that 100% reliability is a very important goal but my weight restrictions are more pressing.

[Clark Leighs]

Reason???  Was there a mssg. about why?   Yeah, I know the feeling.

I have lost posts, not on this forum so far, usually because I left finishing it due to interference or a distraction  for to long a period of time.    If I even suspect I have done that I highlight and copy it.      

 

Then all I need to do is reinstall it and carry on.    Took me a while to clue in and once in a while I will get caught.

[Carl Almond]

My post was blocked. Not going to retype it…

[Tony Athens]

Carl,   May I ask you this?—————–What do you actually expect to get by reducing the battery weigh of your vessel by XXX?  lbs vs. that fact that with a separate banks for each engine, set up right, gives you true twin engine reliability should some go wrong electrically with either engine?

[Clark Leighs]

I am not the one who had Li problems.  I did have trouble years ago with my GEL cell system due to overpromotion of those batteries and ignorance on my part.    They too had needs different from the wet cells  but all the sales people were no better educated that I was , or the other customers.  The GELS got a bad reputation which they did not deserve IF you set them up properly.   But too many people did not want to alter the rest of the system so suffered a shortened battery life.

However:

There are many posts of people who have had good success and are quite pleased with the Li.

BUT they have, in all cases, outfitted the battery system with external alternator regulators with temp. sensing,  sometimes larger and heavier duty alternators and usually a BMS for safety sake. [Battery monitoring system].

Without the BMS there is a possibility of  trouble in the batteries themselves.  

TO charge the other  non Li batteries properly usually requires a DC-DC charger set to charge those non Li batteries  as they need.

 

There are some Li Batts that have a BMS built in but those things are yet very expensive and usually fairly large to make the BMS cost acceptable in relation to the package.

As greater use is made of them the knowledge will grow. 

 

[Carl Almond]

Clark,

I believe I saw another of your posts where you described your issues with using Li batteries and the engine alternators. These guys believe they have things sorted but I am not against letting others give it a try and making the change in a few years after others have blazed the trail.  Grin.

[Carl Almond]

Rob,

I will grant you that it is a steep upcharge to go all in… You do propose a reasonable alternative that is much cheaper. ThanX.

[Clark Leighs]

I agree with Rob that a group 31 battery, wet cell would be more than enough to start you engines, one per engine.    Then use the money to upgrade your house set if needed.   And use the time bough to really dig into the Li if you still want them later.

I disagree that that the LiFePO4 are going to work as the SALES people say.

Typically need an externally regulated alternator.  The reg. needs a temperature sensor for the alternator.   The Li can take a large amount of current which can cook your alternator.   They typically also need a different charging voltage  or can be damaged.     

 

THey are a good battery and can be made to work BUT there is more to this than you have been lead to believe.

No I am not one to advise for that but dug into it enough to be aware there are many pitfalls.    

 

Do some more research.

 

[Rob Schepis]

That is crazy money just to start an engine.  Shed weight and save space and save money and go from your two GRP27’s to a single GRP31.  I got 5 trouble free seasons out of a single dedicated Deka 1231PMF for each of my 6BTA’s.  They were still so strong when I yanked them that my buddy put them in his boat and he has two seasons on them now.  And those Li-ions are for deep cycle applications, not cranking.

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