I don't own an Ultrex with 50Ah lithiums, but here's my opinion. 50Ah is pushing the envelope due to the battery 1C discharge rate. (applies to any 1C rated LiFePO4 battery, Ionic 50Ah is 1C as well). Ionic 24v Example Case

An Ultrex is rated to 56A max draw. These LiTime batteries are rated to a 1C (50A) continuous discharge rate. There's a strong chance that when you run the Ultrex at 100%, you will trigger the "over-current" safety feature on the batteries and they will cut power after ~10 seconds. (Batteries have a 2C max discharge for 10s). If you want to run it on 80% instead of 100%, you'll have no problem.

How do you fix that? One of two ways.

• 1) Increase the battery size. (60Ah x 1C = 60A)
• 2) Find a higher continuous C-rate battery. 50Ah x 1.2C = 60A

The cheapest I could find that should work is Eco-Worthy 50Ah (ad) it is a 1.2C discharge rate as listed on their website. However their customer support if you have an issue will very likely be nowhere as good as if you bought an Ionic. Be sure to compare the warranty as well, Eco-worthy was only 3-years the last time I checked.

There's a good comparison of size and C-rate of this size battery in this video. Hope it helps!

*disclaimer* some battery companies "under-rate" their batteries so that they hit the capacity at their end of life. SO if the "Ionic 50Ah" is really "56Ah", then it will work fine. I don't have a great way to predict that, however.

I have 4 ionics and 1 powerhouse lithium dedicated 16 volt for graphs. They are worry free.

I’d guess they’d work ok. The 50Ah Ionics work great. Maybe there is a difference in the BMS for the money?

Thank you for the detailed reply!

I was reading on BBC someone having a similar issue with the 100% vs 80.
Someone told him it cause he was running a 24v single battery? Having two(50ah) would
Fix it? Hell now I'll really confused.

Every thing I have read says 50 would do. But then I read what I said above.
One thing everyone does agree on is they will not start a motor if needed.

Barret- you running 50 or 100ah?

Kinda the only difference I saw Steeze.


I already ordered 3 100 ah from Litime but I'm cheap and could
Use the 250$ ID save.

I've sent Litime an email last night. Waiting on a response.

I've been using 50a Ionic's for two and a half years now on my 36v Ultrex and now my Quest and never had a problem. Lots of other people have as well.

I have 3- 50 AH trolling motor batteries, A 125 AH cranking battery (complete over kill but was using this to power the entire boat), and a 100 AH 16 volt lithium PH battery with a run and gun charger that powers 3 12 Helixs and a 16 inch Garmin.

I have an Ultrex 112 on a 20' boat. I have three 12" graphs with Livescope and M360. I have a 125ah starting battery and 3ea 50ah Ionic lithiums. We fished all day yesterday in a tournament and ran livewells all day. It was a little windy and I stayed on the TM a lot.

At the end of the day my battery readouts were:
125ah-82%
50ah-84%
50ah-85%
50ah-85%

Both yall got some nice set ups. Appreciate the feed back.


Litime asked what size thrust I had. Guess I should of mentioned that.


Still wonder why theirs wouldn't be sufficient per thier website
If I bought 3 50AHs. Can't remember the last time I fished over 7 hrs in a day.

Cheers.

Some of the new motors pull 60amps while on High power. If you were on an electric TM only lake and were running on High, you’d have no batteries in less than an hour (with 50ah). Granted not many run that hard for that long, but we have a TM only lake here and it’ll put a hurt to small TM batteries. I could kill a set of 100ah if I tried at the TM only lake.

At a regular lake, I only drop my 100ah batteries 10%-30%.

Anyone have any experience with the power queen lithium batteries?

I've read tons of reviews about alot of lithiums lately. One about power queen
Claimed he got water into battery and they wouldn't replace it. He said it's
Not made for boats.

I started looking else where.

I have no issues with theirs. They also have a "trolling motor" version

Great info, It's finally come that time. We finished a tournament Saturday running my Fortrex on high just to get around. I was hoping to finish the THSBA season with the set of lead acid batteries I have but that may not happen. I've got the MK330D charger in my boat; 24 volt system, and everything I've read says it will work with lithium batteries in the AGM mode. The one question I have is how do you mount these 50AH Ionic batteries in place of these massive group 27 or larger lead acid deep cycle marine batteries?

Two of the 50Ah Ionics will ALMOST fit in a standard 31 size tray. I simply cut the edge off of one tray and use two straps. I’ll get ya pictures of how they are mounted if your interested.

yes please