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**moc** · 10-03-2018, 01:47 PM

I built three battery power boxes in my time. It is a fun project. I use to use one for my fish finder, and I have another one that I use to power my electric fillet knife. You can see briefly two of them that currently use... https://www.youtube.com/watch?v=6jDBXiNn4FM

**smithmal** · 10-03-2018, 02:32 PM

MOC,

Thanks for sharing. That's a really cool portable fish cleaning setup up you've got there. It's something I had not thought about at all (mainly b/c I don't catch alot of fish I suppose).

smithmal

**moc** · 10-03-2018, 03:28 PM

My wife prefers that there are no scales in the sink...

The battery boxes that I made all use a cigarette 12 outlet and USBs along with a volt meter, so I know how much charge that I have left in my batteries. I first saw the battery boxes being made, a long time ago on YouTube. I then built my first one with Coop1486 on this forum after we started to talk about them.

**MetroMan** · 10-04-2018, 10:51 AM

Has anyone looked into building a DIY Lithium Trolling Motor Battery

Yeah, I've been using a lithium battery that I've built for quite a few years now to power my trolling motor. LiFeYPO4, 60aH (Yttrium adds better extreme cold weather performance/stability...not really critical for our region though). Cost me a few hundred buck when all was said & done. Availability was scarce back then, so I ended up sourcing my cells from a supplier in China. N

**smithmal** · 10-05-2018, 01:25 PM

Originally posted by MetroMan View Post

Yeah, I've been using a lithium battery that I've built for quite a few years now to power my trolling motor. LiFeYPO4, 60aH (Yttrium adds better extreme cold weather performance/stability...not really critical for our region though). Cost me a few hundred buck when all was said & done. Availability was scarce back then, so I ended up sourcing my cells from a supplier in China. N

MM,

I've heard great things about the LiFeYPO4 lithium chemistry regarding it's ability to work well in cold environments. Like you said though, from a motor trolling battery perspective in this area, it's cold temp qualities aren't really necessary.

Could you answer the following questions for me:
1. Can you tell me what cells you used to build your battery (type, capacity, voltage and manufacturer)?
2. What orientation is your battery in (e.g. 4s12p)?
3. Do you use a Battery Management System (BMS) with it and if so, which one?
4. What gauge wiring are you using and are you using marine grade wiring?
5. What voltage do you charge it to and how far down do you discharge before you need to charge again?
6. What charger you use?
7. What casing did you put it into?
8.Do you ever notice any heat issues with your battery?
9. How much does the battery pack weigh?
10. Do you use the battery just for your trolling motor or do you use it for other electronics as well?

Thanks,

smithmal

**MetroMan** · 10-07-2018, 09:05 AM

Originally posted by smithmal View Post

1. Can you tell me what cells you used to build your battery (type, capacity, voltage and manufacturer)?

I use Winston LiFeYPO4 cells, 3.2v, 60aH. https://www.ev-power.eu/Winston-40Ah...b36kfbarnsr080. I think I recall paying a little bit less when I purchased my cells (but nothing too significant)

2. What orientation is your battery in (e.g. 4s12p)?

Simply wired in series, creating a 12.8V nominal battery pack. (4S)

3. Do you use a Battery Management System (BMS) with it and if so, which one?

I use this: https://www.batteryspace.com/PCM-wit...30A-limit.aspx It performs the cell balancing, protects from overcharging, and protects from overdischarging. Full-fledged BMSs can get pricey...and seem to be overkill for my application. Simply hasn't been necessary in my years of experience.

4. What gauge wiring are you using and are you using marine grade wiring?

I honestly don't remember which gauge, but I know it was either 10 or 12. Been so long since I've wired it. I DO know that it is not marine grade wiring for the battery itself. The rest of the wiring system within my kayak is separate however.

5. What voltage do you charge it to and how far down do you discharge before you need to charge again?

Fully charged at approx 13.26v, at 15A. As far as discharge...I haven't tracked that in YEARS. I used to monitor all of those metrics when this whole lithium battery business was new to me. I used this: https://www.rc-electronics-usa.com/a...y-monitor.html. After a couple of seasons, I learned what to expect from the battery, performance-wise (i.e. amp draw at various speed settings, aH consumed after various lengths of fishing trips, etc.) It was clear that I would rarely have to worry about draining the battery, so I stopped using it. I just charge it...go out and fish. I have used it multiple times without charging in between. I rarely run at full speed more than a few minutes at a time, so amp draw remains low...so it always outlasts my desire to be on the water.

6. What charger you use?

I used to use this: https://www.batteryspace.com/Smart-C...tery-Pack.aspx But now I've been using a regular Shumacher 15A charger.

7. What casing did you put it into?

Nothing fancy...I just keep it in a dry bag for convenient carrying. My battery has been submerged by accident before with no negative effect. As with any battery though, I handle it with care making sure not to drop it or anything like that.

8.Do you ever notice any heat issues with your battery?

No, not at all

9. How much does the battery pack weigh?

Just about 21lbs. Much lighter than the 53-58lb Group 24 marine deep cycle battery it replaces. I keep my battery in the bow hatch when in use.

10. Do you use the battery just for your trolling motor or do you use it for other electronics as well?

Just for the trolling motor. It could easily power anything I'd need, but that would result in more connections...which means more potential points of corrosion. Also, there are times where I do not use my motor, but still use my GPS/FF...much easier to just use my small 7aH battery.

Foursteps24 & I have also had great success using this (even smaller) battery: https://www.batteryspace.com/custom-...-40a-rate.aspx Slightly smaller capacity but that has only been an issue during all-day affairs like tournaments. (I no longer use/have this unit though.)

**smithmal** · 10-07-2018, 03:09 PM

MM,

Thanks for the thorough reply. I appreciate it. I read a lot about those "monolithic" LiFeYPO4 cells. Using them in a series alone certainly does make one's life a lot easier in terms of wiring. In case anyone is interested, someone decided to "dissect" a monolithic battery pack and you can see the vid on it here: https://www.youtube.com/watch?v=MUg9W4CbZUQ
.

I've decided to make mine out of Headway 3820s 3.2V 8ah batteries which are incredibly powerful batteries (capable of 200A continuous and has a 25C rating; using 4 of these batteries in series is powerful enough to use as a car battery jump pack). I choose these batteries because:

1. Very good safety record
2. Use LiFePO4 chemistry allowing one to get as close as 12V as possible making it an efficient battery pack
3. >2000 life cycles
4. Very high amp output (200A) so my battery should never be stressed during discharge events with a trolling motor
5. Got them 50% off (salvaged cells)

I intend to start with a 48aH pack in a 4s6p orientation and if I need to make another pack and put it in parallel (to make a 96aH pack) I can do that at a later time. A thorough video discussing these batteries can be found here: https://www.youtube.com/watch?v=XbuZbFq25gE

The first step is to make the battery pack. I'm discussing the battery build at a battery forum called Endless Sphere (thread link: https://endless-sphere.com/forums/vi...96701#p1416859). I'm hoping to have this battery built with a BT Battery Mananagement System (BMS) so I can watch charge/discharge and program battery balancing from my phone.

After the battery pack is built I'll move forward with the Powerbox build (which I'll be discussing here). I wanted to have an extremely rugged PowerBox which was somewhat water resistant so I purchased a used Hardigg Military case to turn into my PowerBox (link: https://www.ebay.com/itm/223077040641?ul_noapp=true). I'd like the box to have utility other than just fishing so I plan on adding the following components (which I will try to have at least IP65 rating):

- QC 3.0 USB slots
- 12V adaptor slot
- Volt-meter
- LED spot lots
- BT AM/FM/SD card head unit
- 1.5" speakers (2x)
- Charging Port
- 120AC plug (maybe)
- 6 switches (Main Power, Trolling Engine Power, USB Power, 12V power, LED light power, Radio Power)

I'll come back here to discuss the PowerBox build after the battery pack is built and ready to install into the hard case.

Thanks,

mal

**MetroMan** · 10-08-2018, 10:49 AM

Best of luck! Sounds like you’ve got a good plan.

**Pat Smith** · 10-08-2018, 03:47 PM

out of curiosity.. why not get this guy https://www.ev-power.eu/LiFeYPO4-bat...LP12V90AH.html

It seems they have done all the work for you. They say it is monolithic meaning you don't need a balance discharge controller (according to them). Am I missing something with this, seems like an easy solution.. get this battery, a compatible charger, and maybe a volt meter and you should be all set.. unless I am missing something.

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DIY Lithium Battery Power Box for Trolling Motor/Fishing Accessories

DIY Lithium Battery Power Box for Trolling Motor/Fishing Accessories

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