A couple lifepo4 battery questions...

Josh · May 24, 2022

1. If I have a little 30lb thrust minn kota, a 35ah lifepo4 battery should be fine right? That's what I'm getting out of this chart that @cdnred posted on the other thread.
2. If I decide to get a bigger motor, like a 45lb thrust at some point to have a foot control, I would need to up that to a 50ah battery, right? Or get another 35ah and wire it in parallel? What about a 55lb? Can a 50ah lifepo4 battery run one of those? Or do you have to step up further?
3. Does anyone know if you are supposed to keep these lifepo4 batteries in vented boxes? I can't find an answer.

Thanks folks.

wanderingrichard · May 24, 2022

Josh said:
1. If I have a little 30lb thrust minn kota, a 35ah lifepo4 battery should be fine right? That's what I'm getting out of this chart that @cdnred posted on the other thread.
2. If I decide to get a bigger motor, like a 45lb thrust at some point to have a foot control, I would need to up that to a 50ah battery, right? Or get another 35 and wire it in parallel? What about a 55lb? Can a 50ah lifepo4 battery run one of those? Or do you have to step up further?
3. Does anyone know if you are supposed to keep these lifepo4 batteries in vented boxes? I can't find an answer.

Thanks folks.

I'd vent just to prevent any possibility of a gas explosion of any type.

_WW_ · May 24, 2022

I just got a 50ah for my 30 lb minn kota. It's only 12lbs plus it can do double duty on my travel trailer if needed.
I don't think venting is required because they are totally sealed and can even be used while on their side.

cdnred · May 24, 2022

I agree with what @WW mentioned about the venting and the longer duration a bigger battery will provide you with. I think the driving force will be much much you're looking to spend for a battery..

SurfnFish · May 24, 2022

You'll be fine for running spot to spot, likely get a few hours of trolling out of it. 36# Minn Kota on my 13' skiff runs off a 35AH AGM wheelchair battery, pick up and full twist to the next spot, run a mile or so during a session, get home with over 50% of charge.
Ran a 55# on a 16' tidewater skiff powered off a 75AH AGM, could run a coupla miles and still be above 50%.
Regarding connecting batteries:

How To Connect Batteries In Series and Parallel

Learn how to configure batteries in series, parallel, or series and parallel. Complete battery configuration guide for increased power at BatteryStuff.com!

www.batterystuff.com

Sam Roffe · May 24, 2022

no need to vent. They do not off gas during charging. LiFePo4 batteries are a very stable chemistry. Many RVers keep the. Inside their living space.

as far as capacity for trolling motors, it’s just balancing current draw and length of runtime you want. Obviously the more batteries, the longer the run time. You can run batteries in parallel. Use hefty battery cables.

Josh · May 24, 2022

Sam Roffe said:
You can run batteries in parallel. Use hefty battery cables.

Is running in parallel difficult or annoying to get set up? Or is it as simple as it appears?

Old406Kid · May 24, 2022

Josh said:
Is running in parallel difficult or annoying to get set up? Or is it as simple as it appears?

SurfnFish · May 25, 2022

One thing to keep in mind when using trolling batteries (aside from lithium, a whole other deal), is to never discharge them below 50%, dramatically shortens useful life. Hard to beat the pure utility of the 35AH batteries, so light, string them together for more amp reserve.

Sam Roffe · May 25, 2022

Wiring in parallel is not difficult. As @Old406Kids posted a picture, you have two additional jumpers between the two batteries. Negative post goes to Negative post (Black to Black) and Positive post goes to the Positive post (Red to Red).

Just use appropriate sized wire between the two posts. Minn Kota has a chart of wire size to use. Size is determined by the amperage draw and length from the battery bank to the trolling motor.

I would also recommend using good quality hardware. When I rewired my trailer with lithium batteries last year, I bought a hydraulic crimp tool to build my own battery cables and jumpers. As a side note, I would be happy to help build battery jumper cables if anyone needs any.

Sam

Ronbow · May 26, 2022

Be sure to know the max and continuous amp draw of your tm, and match battery to the motor. AGM has good amp capacity even in smaller ah batteries. The LiFePo4 amp capacity is less so will need a bigger battery as thrust increases to get amps up. My 36ah LiFePo4 is really great for 24# Watersnake.

PhilR · Aug 10, 2022

Resurrecting this, since I've had a couple of outings with my Weize 50ah battery. So light, and easy to load. A couple of downsides, though. First, you get it down below 11V and it just shuts off. No warning, no apologies. I had to put in the oars and oarlocks to row the last 20 feet to the dock. I guess this is expected, but was still a bit of a shock. Second, if you transport the battery with the terminal screws loose, they'll back themselves out. I can't figure out where one of them went in the back of my car, and have to source a replacement. Overall, though, great range, easy to charge, and light weight.

Josh · Aug 10, 2022

PhilR said:
Second, if you transport the battery with the terminal screws loose, they'll back themselves out.

Thank you for the warning because I'm SURE I would have done this.

_WW_ · Aug 10, 2022

What I have done is wired a cord in that I can plug my motor into or the charge controller from my solar panel. Tightened those screw down good and tight. Also when charging, plug in the battery first, then power up the charger. DO NOT short circuit these batteries! It kills them. I keep mine in a waterproof bag and close the zipper all the way until only the wires poke out. Before the bag I would cover the top with a big ziplock.

Steve_S · Aug 12, 2022

Josh said:
Thank you for the warning because I'm SURE I would have done this.

Wrap the top couple threads in plumbers' tape or dab a little UV cure in there. You can always easily remove it.

Aleforme · Aug 16, 2022

I'm actually looking at either 46 or 55lb Newport Vessels Motor of a Minn Kota 55lb and will probably pair it with a 100ah lifepo4 battery just to keep the run time up a bit on some longer lakes I'll be fishing.

The one thing that it a confusing is the charging it doesn't sound like my normal battery charger will work so wondering if something like this would be fine? Seems like charges are all over the place in proving. At about $50, seems like a decent deal.

What do you guys charge your lifepo4 batteries with?

Sorry to hi-jack the thread a bit.

Josh · Aug 16, 2022

Aleforme said:
so wondering if something like this would be fine?

Looks like maybe the link to whatever product you are asking about didn't get in there?

In any case, I use a Noco Genius 10 charger. The Genius 5 or even Genius 1 will work for lifepo4 batteries. But the 10 was faster and had more features.

Aleforme · Aug 16, 2022

Josh said:
Looks like maybe the link to whatever product you are asking about didn't get in there?

In any case, I use a Noco Genius 10 charger. The Genius 5 or even Genius 1 will work for lifepo4 batteries. But the 10 was faster and had more features.

Whoops, here is the one I was looking at.

https://www.amazon.com/Automotive-Detection-TB8000-Automatic-Maintainer/dp/B09WHDRF4T/?_encoding=UTF8&pd_rd_w=M4v5b&content-id=amzn1.sym.e4bd6ac6-9035-4a04-92a6-fc4ad60e09ad&pf_rd_p=e4bd6ac6-9035-4a04-92a6-fc4ad60e09ad&pf_rd_r=TNMD8W3ZK7RWMVR51CJ2&pd_rd_wg=UXetA&pd_rd_r=003250ce-6a5b-4bd7-9fc7-14451bb911a8&ref_=pd_gw_ci_mcx_mr_hp_atf_m

That Noco looks similar.

Ronbow · Aug 16, 2022

Also use Noco Genius 10. Nice to have more amps, shorter charge time. One you found looks good too. Ron

_WW_ · Aug 17, 2022

Aleforme said:
I'm actually looking at either 46 or 55lb Newport Vessels Motor of a Minn Kota 55lb and will probably pair it with a 100ah lifepo4 battery just to keep the run time up a bit on some longer lakes I'll be fishing.

The one thing that it a confusing is the charging it doesn't sound like my normal battery charger will work so wondering if something like this would be fine? Seems like charges are all over the place in proving. At about $50, seems like a decent deal.

What do you guys charge your lifepo4 batteries with?

Sorry to hi-jack the thread a bit.

With a 100 ah battery you may want something with more than 8 amps charging to take advantage of the quick charge capability of the LiFePo4.