Can I use a car battery for pic related?
I wanna buy both the motor and battery but the batteries seem expensive as frick. There's all sort of different ones lithium or gel or whatever the frick. You pay like €130 or more for a 12v 18amp thingy but these car batteries are 12v 54amp for only €70 so you get more for less or how does it work?
Sure
Then why are these boat accus so expensive?
Do you know what ah I should look into getting?
That thing has 58lbs of thrust or something
or how do I calculate it
and do I need to waterproof the battery or could I just do something like put it in a tupperware container and make wires come out waterproof?
batteries*
I find them like 12v 70ah for like €70 which seems like a good price, but how many hours can I use that 58lbs thing for on lets say half speed?
how2calculate
Because anything with a boating or marine suffix commands a premium from boaters with more money than sense.
It's how some people think military grade is a sign of quality and not just functional shit churned out by the lowest bidder
okay ty ill just try to find the cheapest 12v 100ah battery i can find then
Don’t be fooled by ‘boat’ or ‘car’ or whatever battery. There is no implicit difference.
Car batteries, however, are not meant to deep discharge because in normal cases you’d never discharge them all the way. That allows for a cheaper chemistry hence they are cheaper. Marine batteries come at a premium because they are ‘moisture proof’ and may have even some ingress protection rating when used with waterproof connectors. Lead acid and NiCd batteries when deep discharged give off H2S, which isn’t always safe on a boat, so lithium is more popular. Superior to car batteries in many ways but a lot more expensive.
> and do I need to waterproof the battery or could I just do something like put it in a tupperware container and make wires come out waterproof?
Yes but no, you need to ventilate them to avoid h2s buildup. There are special boat battery boxes for this purpose with ingress rated connectors installed in the lid.
Oh I just thought i'd put the battery in one of those plastic ikea boxes and put a strap around it
so kinda waterproof for when you are wet and dry off next to it for example but not underwater diving proof
would it be sufficient?
im trying to be as cheap as possible solution to get
the motor here working and also get some hours out of it
If you really want to Jerry rig it but safely, get 3 waterproof cable glands, use two for the battery cables and one for a long tube that you run somewhere (upward) where it doesn’t get wet. LiPo and LiIon batteries don’t need to be ventilated.
Fire code for batteries requires active ventilation (ie using a fan) but I’m not sure if it’s really important
>waterproof cable glands
thanks ill look into this
i thought maybe also a rubber strip around the edge of the box or something but yeah if these cheap batteries niet to ventilator or built up guest I think only splash water proof should be enough right
*need to ventilate or build up gas
damn been long day anyway thanks for the help
I’m sure at least one person mentioned it among the dumb responses, but marine batteries are normally “Deep Cycle”. You can get a big 100Ah car battery that will work, but car batteries are made to dump a lot of power to start the car and then be recharged by the alternator. They won’t have a long life if you’re draining down to 20% and recharged at home. Deep cycle batteries are much better for this, whether or not it says it’s for a boat.
Do some research on AGM and stuff too, I’m not positive but I have a feeling the acid slushing around in a regular flooded battery might not be great on a rocking boat.
but isnt acid slushing around in cars the same problem then?
So basicly what you're saying is I should just skip the whole car battery cause its probably not gonna work? Either break down or have shit performance?
Car battery won't work due to anons stated issues. Just go on youtube and look up battery systems people use for renewables. If you want you can diy the battery meaning you can but individual cells and hook them up any which way you want but that'll require some research and equipment.
Don't expect your batteries to last forever though no matter how much you try and stop water ingress, water will find any little crack and penetrate eventually, that's why marine stuff is such a pain to maintain
The same shop that sells the electric motor has a 105ah lead battery, but they write it can only be discharged 60% for best endurance. But I guess it's specificly meant for boats and alot of charging then, since they sell it too as their "best value" ? Its €150 for 12v 105ah lead battery
It will work, but regular lead acid batteries really don’t like to sit at lower states of charge or being discharged real low. That’s why if you forget your car lights a couple times and have to jump it, sometimes the battery will be trash even if it’s a year old. Deep cycle batteries will likely last a lot longer and hold a better charge after a couple years of use.
I think a lot of motorcycles and sports cars that do more than basic commuting are going to have at minimum AGM batteries, and more of them have lithium every day. Typical car batteries aren’t sealed very well and I don’t know how great that would be on a boat unless you keep it real calm.
> I think a lot of motorcycles and sports cars that do more than basic commuting
Older motorcycle lead batteries are ‘open’ and have an overflow hose that runs all the way down for acid spills. Also means they have to be filled every now and then.
AGM deep cycle battery. Don’t worry about ventilation, just keep it off the floor, but some roof, and cover the contacts. Unless you’re building a submarine it shouldn’t be hard to keep it dry enough
The thrust rating is just how hard the trolling motor can pull, not power consumption BUT! a higher thrust rating will probably mean greater power consumption. If you want to calculate the power consumption then you will need to find out how many watts the trolling motor pulls at the power setting you wish to be using and for how long you wish to be on the water.
>and do I need to waterproof the battery or could I just do something like put it in a tupperware container and make wires come out waterproof?
Not necessary. The trolling motor will come with connectors to attach to the battery and its fairly idiot proof. You won't get electrocuted from 12/24V if it touches water. and it won't hamper performance or damage your battery if a little water gets dripped on it unless your battery is literally underwater.
and then of course waterproofing the wires coming out of the lid
and putting a big strap around it
probably also use styro foam to get the battery to sit snug in the box
I mean it should be enough to get it working and relative safe right?
its meant to be as cheap as possible and still okay-ish, not meant to be professional best blabla quality and safety ever
Probably gonna have to do something about corrosion
im not planning on driving on salt water
You will still be at a huge corrosion risk as compared to a car
and as other anons have said a car battery will work but it will have shit indurance and not want to discharge as low as a deep cycle battery.
there is actually a trade off in aps and depth of discharge even for equally high quality batteries because the multiple layers of anode in a car battery allow higher amperage but the solid anodes of a deep cycle are less prone to wear and have performance and degradation curves that don't fall of ass fast as the high amp car stile cells.