48v LiFePO4 need your help goldenmotor 15k/48v water cooled

need your help golden 15k/48v water cooled at 3500 rpm full thottle spec say 8amps motor going to be used on a 20 ft pontoon boat ? 12v or24v sys how many panel,batterys and how big controller no inverter just run dc motor how do i get the numbers to work out

Need some info:

A link to the motor specs and how long you wish to run it each day.

Add how many days between use to recharge and people can help you.

If its this one the product description says 135 amps no?

smitty not sure how to set up my thread for the 15k 48v golden motor not use to doing this computer thing to talk to people about my problem tell me how to do this old fart smitty

Smitty said:

smitty not sure how to set up my thread for the 15k 48v golden motor not use to doing this computer thing to talk to people about my problem tell me how to do this old fart smitty

Click to expand...

You pick the right sub-forum for the topic. Like General Battery Discussion.
At the top of the forum page there's a box the says thread title.
Put your title there and the box under it put your statement/question.
It's easy after the first time you do it.

web site www.goldenmotor.com 15kv/48v dc motor test and spec's for this motor this could help to set up my solar sys for the pontoon

So if I am reading the specs right then the motor does indeed use 135 amps.

That is a LOT.

Some of the bigger batteries people are building here are using the 280Ah XUBA cells. You would need 16 of those to build a 48v battery and the battery will weigh in around 240 pounds if I recall correctly.

So this big battery would give you 2 hours of run time since 135 amps X 2 hours = 270 amps

That is IF you could use 100% of the battery capacity. In the real world you cannot, but lets ignore that for a moment.

So your 270 amps need to be replaced by your solar panels after a 2 hour ride.

270 amps X 48v = 12,960 Watts.

Again, that's a LOT.

IF you had a 1000 watts of solar panels and you could maybe count on 4 hours per day of that production. So let's be optimistic and say you can generate 4000 watts of power per day.

That means it would take over 3 days to recharge the power you used on a 2 hour boat ride. Probably not the answer you were hoping for.

This is some quick and dirty math off the top of my head. I welcome anyone from the forum to check if I made a major mistake on this ballpark estimate for a reality check.

thanks for the info a may have to stay with a gas power outboard that sucks i had hope to power by a electric motor building roof right now to hold the solar panels the cost to do this is over my budget thanks smitty

Any idea where you got the notion it was 8 amps at full throttle?

That would be doable but I cannot figure out how you came up with that number

JoeHam said:

I welcome anyone from the forum to check if I made a major mistake on this ballpark estimate for a reality check.

Click to expand...

Sounds about right.

@Smitty do you have access to the grid or is solar your only option? Can you use wind power? Or a genset?

There is definitely a workable solution here.

How long do you need the motor to be operational per day? @JoeHam used a typical DIY battery pack that would give you 2 hours run time. Is that enough? Frankly, you're not going to get a higher density energy source than Lithium-ion right now so if you want a DC powered outboard, the answer is, well, how big does the lithium-ion battery bank need to be? For example, 1 hour runtime = 135AH, 2 hours = 270AH, 3 hours = 405AH etc.

Now you have the battery pack, we need to charge it. What options do we have? Solar/Wind/Grid/Genset/Hydro etc

For example, let's say 2 hours runtime is good enough, you can buy a 100A grid charger that would recharge that 270AH battery bank in 2.7 hours. Buy two, when one is fully discharged, the other will be almost fully charged - play all day!

I'm just saying that there are options.