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Re: Lithium Boat Battery
Posted: Tue Jan 28, 2020 5:33 pm
by ducky
I was looking at the 50odd ah lithium battery at the fundraiser and the claim was its usable current was equivalent to a 100ah battery due to being able to run them to zero.
Didn’t look into whether that’s true or not but even if it’s a half truth there’s not that big a stretch to get one. Perfect for little boats especially where weight is a concern.
Re: Lithium Boat Battery
Posted: Tue Jan 28, 2020 9:31 pm
by Redhunter
Sinsemilla wrote: ↑Tue Jan 28, 2020 5:31 pm
Redhunter wrote: ↑Tue Jan 28, 2020 12:47 pm
Considering the headaches involved with simply freighting lithium batteries, due to them being being unstable and susceptible to igniting, there’s no chance I would personally put one in a boat.
Pros - lighter in weight and you can get more out of them.
Cons - may burn your boat down.
You must be really old school Redhunter.. Nearly every electronic gadget you own has a lithium battery in it. Cars have lithium batteries and are running on lithium batteries these days.
I've been running lithium batteries on my 2 stroke for years and with all the banging around and vibration the bike puts out i haven't had a fire yet..
I think you'll find, just like anything else, if you buy quality you won't have an issue.
Pros - Lighter, Quicker to charge, Can ran them down to 0%, Fully sealed, No maintenance (apart from charging), can put up with vibrations and last a lot longer than lead acid batteries.
Cons - Expensive.
Anth
You try telling that to the aviation and maritime authorities! Lol. Yes I’m aware lithium batteries are in all sorts of gadgets nowadays, however most of those are only small bangers. Anything above 100 watt hours is deemed dangerous goods. Not a regulation I make up, just one of the many I need to adhere to. These are the size batteries worth considering if willing to go that way I reckon, and they’d only be warranted if used in conjunction with an electric motor really, otherwise the major benefits wouldn’t be there. There is a massive difference between a boat’s ride, and that of a dirt bike. A dirt bike has pneumatic tyres and suspension to absorb the bumps, a boat does not have anything other than a contoured hull. A heavy boat will be a softer ride, and a lighter boat will be a harder ride. Irrespective, there is much more jarring and banging and crashing involved with the ride of a boat than a dirt bike. I’m not saying it will burst into flames, but I wouldn’t want to take that risk personally. Up to you dude...
Re: Lithium Boat Battery
Posted: Tue Jan 28, 2020 9:47 pm
by Sinsemilla
Redhunter wrote: ↑Tue Jan 28, 2020 9:31 pm
Sinsemilla wrote: ↑Tue Jan 28, 2020 5:31 pm
Redhunter wrote: ↑Tue Jan 28, 2020 12:47 pm
Considering the headaches involved with simply freighting lithium batteries, due to them being being unstable and susceptible to igniting, there’s no chance I would personally put one in a boat.
Pros - lighter in weight and you can get more out of them.
Cons - may burn your boat down.
You must be really old school Redhunter.. Nearly every electronic gadget you own has a lithium battery in it. Cars have lithium batteries and are running on lithium batteries these days.
I've been running lithium batteries on my 2 stroke for years and with all the banging around and vibration the bike puts out i haven't had a fire yet..
I think you'll find, just like anything else, if you buy quality you won't have an issue.
Pros - Lighter, Quicker to charge, Can ran them down to 0%, Fully sealed, No maintenance (apart from charging), can put up with vibrations and last a lot longer than lead acid batteries.
Cons - Expensive.
Anth
You try telling that to the aviation and maritime authorities! Lol. Yes I’m aware lithium batteries are in all sorts of gadgets nowadays, however most of those are only small bangers. Anything above 100 watt hours is deemed dangerous goods. Not a regulation I make up, just one of the many I need to adhere to. These are the size batteries worth considering if willing to go that way I reckon, and they’d only be warranted if used in conjunction with an electric motor really, otherwise the major benefits wouldn’t be there. There is a massive difference between a boat’s ride, and that of a dirt bike. A dirt bike has pneumatic tyres and suspension to absorb the bumps, a boat does not have anything other than a contoured hull. A heavy boat will be a softer ride, and a lighter boat will be a harder ride. Irrespective, there is much more jarring and banging and crashing involved with the ride of a boat than a dirt bike. I’m not saying it will burst into flames, but I wouldn’t want to take that risk personally. Up to you dude...
I get it, they need to take precautions which is fair enough.
I'm going to disagree with you though on a bike being smoother than a boat.. People actually get handle bars that have rubber grommets because guys get sore wrists and fingers from the vibrations.. I've had a battery almost wear through because of it vibrating and over time the bracket wore through. I can 100% with confidence say a lithium battery is better with vibrations. I actually changed over to the lithium because the vibrations ruined the lead battery it came with.
Re: Lithium Boat Battery
Posted: Wed Jan 29, 2020 8:12 am
by purple5ive
ducky wrote: ↑Tue Jan 28, 2020 5:33 pm
I was looking at the 50odd ah lithium battery at the fundraiser and the claim was its usable current was equivalent to a 100ah battery due to being able to run them to zero.
Didn’t look into whether that’s true or not but even if it’s a half truth there’s not that big a stretch to get one. Perfect for little boats especially where weight is a concern.
Did you happen to get any info on the power output/discharge curve of the battery.
Aka does it drop at a linear rate (useless if going smaller sized ah battery to take advantage of scenario you mentioned) or give you full power till about 90% charge then drop off..
I would think the latter but I'm not sure myself.
Would be great if what they are saying is true.
Re: Lithium Boat Battery
Posted: Wed Jan 29, 2020 9:43 am
by Yota
purple5ive wrote: ↑Wed Jan 29, 2020 8:12 am
ducky wrote: ↑Tue Jan 28, 2020 5:33 pm
I was looking at the 50odd ah lithium battery at the fundraiser and the claim was its usable current was equivalent to a 100ah battery due to being able to run them to zero.
Didn’t look into whether that’s true or not but even if it’s a half truth there’s not that big a stretch to get one. Perfect for little boats especially where weight is a concern.
Did you happen to get any info on the power output/discharge curve of the battery.
Aka does it drop at a linear rate (useless if going smaller sized ah battery to take advantage of scenario you mentioned) or give you full power till about 90% charge then drop off..
I would think the latter but I'm not sure myself.
Would be great if what they are saying is true.
From what I've read, typical discharge curve shows LiFePo batteries holding their full voltage per cell until 85-90% discharged, apart from the deeper duty cycle the other benefit is because the voltage per cell stays higher for longer this equates to steady current draw for longer - unlike a lead acid deep cycle battery where as the battery discharges towards the lower end of its capacity the voltage steadily drops away causing increased current draw.
Re: Lithium Boat Battery
Posted: Mon Feb 03, 2020 9:27 am
by Kennyboy
So actual usability 85%, not 100%? That matches my research on lipo
Re: Lithium Boat Battery
Posted: Mon Feb 03, 2020 10:44 am
by Yota
Kennyboy wrote: ↑Mon Feb 03, 2020 9:27 am
So actual usability 85%, not 100%? That matches my research on lipo
Hi Kenny, yes that’s about it,
This quote from redarc in my 2nd post on this topic :” Each is built from nominally 3.2 volt cells - four provide 12.8 volts at about 97% charge falling to about 12.7 volts at 20% SoC and then falling in a knee-like curve.”
So at about 80% discharge the output drops off quickly.
Interestingly it also states about the various charger manufacturers limiting the final charge voltage to reduce overcharging risks - so typically a LiFePo 2 stage battery charger will limit charging to around 90-95% full charge.
So you can see from this - if you use the battery from 95% fully charged down to say 15% state of charge, you have used 80% capacity anyway.