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I’ve read that lithium batteries charge up very quickly and even get noticeable charge boosts when running the big motor. How long are we talking? How long of a boat run (time) to charge the battery, say 10% more than where it started?
I want to factor this in as I decide what battery I get as far as Amp Hours.
thx
depends on amps going in and out during the time you are running, the Proxs 200 can charge very fast and you could see as much as 60 to 70 amps going into the battery when running , that will depend on how many graphs are running at the time and using up some of the amps from the alternator, many people running a Merc 4 stroke and a 125ah that move around a lot find that their battery stays 80 to 90% all day, others running 5 graphs and FFS that start on the trolling motor all day need more than 125ah
As Drew says “it depends”. I say get a bit more than you think you will need. It is penny wise to scrimp a bit on capacity, but in the long run your battery will thank you in years of service by not draining as much you will add to its life and the lack of worry on your part might benefit your longevity as well. Bob
Do you guys know if a Merc 4-stroke PROXS 200 will put out a bunch of juice even when idling? I could see just starting the motor and letting it idle for 15 minutes if that was going to charge up the battery significantly. I fish some TM-only places all day, dawn to dusk so I’m guessing I should just get a bigger battery though.
Would you be allowed to fire up and idle on "TM-only" places anyway? Seems like that would go against their rules?Quote:
Originally Posted by bman5150
I wasn’t clear in my previous statement. I fish some TM-only lakes and would need to fish dawn to dusk and not complete drain my starter battery since that’s what I would be running my HDS Live 9”, ActiveTarget 2 transducer and HDS Live 12”. I’d also have my console HDS Live 9” but that one would be on standby all day. For these lakes, I wouldn’t be running anything else though (no live wells, etc.)
I also fish some smaller lakes that are idle-only. That’s one situation where I could potentially get some charge back into my batteries if I fished dawn to dusk.
lastly, I fish some bigger waters where I might only make one big run to a particular area and then I’m on the TM the rest of the day. Might make 1-2 more shorter runs before ending the day. Again, if I was fishing in my area and the juice got low, I’m wondering if I could just start the motor and have it idle for 15 minutes to help get some charge into the starter battery.
you can run 2 HDS 9s and a 12 with At2 12+ hours on any quality 120ah to 125ah dual purpose lithium and still start that 200 at the end of the day, any idle time will just add to that
Your battery will take all the amps your system will deliver if it's low. Lithium batteries have a higher voltage than conventional batteries so that can make a difference too. If your regulator is set to the voltage a lead-acid battery needs it might not fully charge a Lithium battery. Experience will tell you.Quote:
Originally Posted by bman5150
What model motors have voltage regulators with adjustable outputs?
My 125ah always seemd to have power to spare, but did some tests this winter running "full tilt" with 4 MFU's, AT, 3DSS, Go Pros, Radio, PP's, etc & my "common" amp draw with livewells running is 14ah... so I'm concerned about getting a full/long day out of it. Now, it's not like I am going to sit in one spot all day and never run the big motor, but still I am thinking about supplementing it with an additonal Ionic in Parallel. Just haven't decided if adding a 50 is enough, or if I should go full out with another 100 or 125ah even.
None that I know of but the system has a preset design voltage. It might be excellent for lead acid but not quite enough to hit 100% on a Lithium.Quote:
Originally Posted by yam911
Quote:
Originally Posted by billnorman1
Most I have seen are in the 14.5v range, pretty good for either chemistry.
Well I'm not sure of the exact charging profile, so I bought Lithium rated chargers for my leaky old scow.Quote:
Originally Posted by goodman_fishing
What from your experience is the minimum voltage to achieve a full charge. I know most say 14.6 is optimum but what is your experience for the min. There has to be a rough minimum. I do know that 14v will charge the ones I have to 90+% as my Lithium chargers add very little to top them off. I also wonder what would be the min voltage to balance the cells also? CJQuote:
Originally Posted by goodman_fishing
Since getting my fusible link replaced on my Merc, I have not had to charge my 125 once. Actually thinking about replacing my 3 bank with a 2 bank just for the TM batteries. Running three 9" graphs plus Livescope in small lakes.
In theory any voltage above the resting voltage should fully charge a battery. It is just going to take a while.Quote:
Originally Posted by CJ1
Playing with a variable voltage power supply and charging my small Ionics battery at 13.5 volts, it will go to 100% SOC.
The individual cell voltage was and is never exactly the same. A few millivolts difference. Not sure what the maximum cell difference can be before the cells are considered to be out of balance.
So 10% more than where it started? 10% of a 120 amp battery is 12 amps. So if the alternator is putting out 60 amps, you will get your 10% in 12 minutes..? Will check that.Quote:
Originally Posted by bman5150
Let's give the math a shot for a 125 Amp Lithium Cranking Battery, a motor that charges at 50 Amps, and fishing electronics that consume 20 Amps, and your battery is currently at 30% (37.5 Amps). The thing to keep in mind is that the alternator and fishing electronics are Amps/Hour. In other words, in one hour the motor will supply 50 Amps of charging and in one hour the Fishing electronics will consume 20 Amps.
I'm going to assume a perfect world and that everything is performing exactly as specified, but this may or may not be the case:
The battery is currently at 37.5 Amps, so let's see where the battery will be in 1 hour with the big motor and the fishing electronics all in use. In one hour, you would have a net of 30 Amps added to the battery (50 charging less 20 discharge = 30 net Amps). Add the 30 Amps to the starting 37.5 Amps and you now have 67.5 Amps. This raises the battery percentage from 30% (37.5 Amps) to 54% (67.5 Amps).
You can see from the above that it takes a while to get any significant net charging to the battery. You can easily do the above with your specific Battery/Alternator/Electronics Amp numbers.
So for his 10% more than where it started, a motor at 50 Amps and with electronics on, ballpark, he will get his 10% in 25 minutes. Ya it pays to turn off electronics if you can.
None are adjustable, most are set to 14.2 to 14.6 max, The lithium battery will accept all the current that is availble without cutting back on charge rate until it is fully charged. For instance, my 2 stroke has a 50 amp alternator, the requires 20 amps to function. at cruising speeds, I have constant 29 amps going into my battery which will replenish it quite fast. Lead acid batteries have a much higher internal resistance, and the current flow will rapidly fall from say 25 to around 10 amps or less going into the battery in just a few minutes,Quote:
Originally Posted by yam911
At idle alternator ouput is very low, most of is needed just to run the motor, allmost nothing left to feed the battery
I wondered if alternator output would be pretty low at idle. So my idea of letting my big motor idle for 15 minutes while I eat lunch or fish wouldn’t really charge the battery much at all. Instead, it sounds like I’d need to make. 10-15 minute run.Quote:
Originally Posted by lpugh
in nearly all of my fishing situations, I usually do make at least a few runs each day. However, there are some situations where I barely use the big motor or don’t use it at all. Looks like I’m going to just have to suck it up and get a lithium with more AHs to account for these scenarios.
Personal test I did: Battery was down to 89%, in a 15-minute run a various speed to another location, the battery was back to 99%, the entire time the app showed 28 to 29 amps going into the battery. This was with a 50-amp alternator, the motor requires 20 of those 50 amps.
:thumb up2:Quote:
Originally Posted by lpugh
@lpugh - thank you for sharing that info.
This is what I am seeing also. When I get more experience with them (mostly need time!) I'll post what I find. I truly believe anything in the 13.9 and up range will fully charge and balance a good lithium battery. CjQuote:
Originally Posted by yam911
I am not getting that deep into it, but it seems 14.4 comes up quite a bit when talking balancing cells. JMO Bob
Mirrors what I saw with my 2016 SHO - bascially pushing out 29amps (to battery) at running speed, and dropping back to single digits at idle speeds.Quote:
Originally Posted by lpugh
so the altenator doesnt provide enough voltage to top it off at 100%? is that what effectively what keeps the BMS overcharging cutoff from engaging?Quote:
Originally Posted by lpugh
it will charge it to 100% with enough run time. The alternator regulator controls voltage to 14.4 to 14.6 volts, it also regulates current flow as the battery voltage comes up to its peak it will reduce current flow as well, BMS will not switch off if regulator is doing its job.Quote:
Originally Posted by MTW
This is why manufactures do not recomend lithium batteries across the board yet.
If the BMS turns off while running the pcm will shut down the motor because the voltage will spike very high, 20 to 60 volts. Possible PCM failure when this happens, hooking the boat or worse!
It is not voltage that tops off a battery at 100% SOC. It is current.Quote:
Originally Posted by MTW
Current flow depends in part on the voltage. Less voltage simply means less current flow which means a bit longer to reach 100% SOC.
Helps at times to think of voltage as pressure. Say fuel pressure from a fuel pump. The higher the fuel pressure the faster gasoline will be flowing. The faster the fuel flow the more quickly a gas tank will reach 100% full.
yeah thats why i ask because someone asked me about their set up with a 250 pro xs was seeing his voltages spike to around 24v sporadically. his units even gave a high voltage alarm. his charging system checked out and the only thing i could think the BMS was disconnecting. i told him to call lithiumhub and talk to their engineers because nothing was wrong with his units.Quote:
Originally Posted by lpugh
which is what i meant voltage at full throttle. i dumb down sometimes so folks can understand. i have a BSEE from UT knoxville and enough electronic certs to wallpaper my bathroom.Quote:
Originally Posted by yam911