Questions Before Buying Lithiums for 24/80 Ultrex

[slabbandit]

Last year I bought a new Ranger 188P. It has a 24 volt 80 thrust Ultrex trolling motor. The boat came with 2 27 series lnterstate lead acid deep cycles dedicated to just the trolling motor. I’ve had no issues running 4 to 5 hours on 5 but lately I run on 9 or 10 when actively scanning for roaming crappie on Livescope. After about 3 hours I have seriously depleted my batteries.
I want to go with 2 100 AH Weize lithiums from Amazon as I have been running one for a year and a half now dedicated to all my electronics without issue. I run a Garmin 934 XSV in the dash and 2 1222’s and black boxes.
My son suggested that I buy one more 100 AH lithium, hook up as 24 volts, and use a “Bandit” Voltage Splitter/ Isolator. I guess this is what they’re called from Monster Marine. He says I can get 24 volts to my trolling motor and 12 to all my electronics with no interference. Thus eliminating the need for a dedicated electronics battery. I’m a little leary of putting any thing on my trolling circuit, especially electronics.
I’ve never heard of doing this and would like to hear all opinions either way on this.

[billnorman1]

Well, if you are going to go to Lithiums, you apparently already have one. The Lithium sales people recommend you buy those which will be used in series at the same or closest to the same time, just like lead-acids. Adding your electronics directly to one of the batteries could be detrimental to the batteries used in series not to mention it could cause interference on your electronics when you use your T/M.
I have never seen this "Bandit voltage splitter/isolator" and cannot find a good reference on my internet, so I'm totally ignorant as to its function. I did go to Monster Marine and saw a $900 unit that appears to be a "charge on the run" item.
Since you already have one of that brand purchased, the best time to pair it up has passed. Maybe just leave the older battery dedicated to your electronics and buy two new ones for trolling would be a good choice.
I don't know if Monster is a BBC sponsor. That could make a difference.

[scubatelco]

I have 2 100ah lithium batteries from China with a 24/12 step down converter, no interference and works great. I have 2 Solix FF, 10 and a 12, with no issues running off the TM (Ulterra 80) batteries and I still have plenty of battery after a day of fishing.

[Bill Reynolds]

I have been involved in 1 1/2 instances using DC Buck converters.
1) I helped a local Crappie Guide reduce his battery count and weight by replacing lead acid with Lithium. We eliminated a stand electronic battery by using a 24/12 buck transformer. It worked out ok: No interference.
1/2) I helped another friend rig up his aluminum river boat with a 36 volt TM removed from his glass boat. He needed 12 volts for his LiveScope and another battery was not an option so we are using a buck transformer. He just finished the install and has not had a chance to try it so we don’t know about interference.

I recommended the one shown because it could handle the 36 volt primary voltage.

[Lowerider58]

There’s a guy on YouTube that does a lot of testing on lithium batteries. He tore apart a Weize battery about the time you bought yours and he was very impressed with it. He considered it the best “cheap cheap Chinese “ lithium battery at that time.

I bought one of the Weize batteries about two months ago and shortly after I bought it he done a follow up video about that battery.
He bought another one and tore it down and the cells and BMS circuit were different from the original one. Same case different guts.
I most likely have the newer one so time will tell if it’s a good one. You should check him out before you buy another one. Theyre not the same battery.

[slabbandit]

Thanks Bill, I really didn't think about the batteries needing to be bought at the same time. You're absolutely right about the batteries needing to be matched.

[slabbandit]

There’s a guy on YouTube that does a lot of testing on lithium batteries. He tore apart a Weize battery about the time you bought yours and he was very impressed with it. He considered it the best “cheap cheap Chinese “ lithium battery at that time.

I bought one of the Weize batteries about two months ago and shortly after I bought it he done a follow up video about that battery.
He bought another one and tore it down and the cells and BMS circuit were different from the original one. Same case different guts.
I most likely have the newer one so time will tell if it’s a good one. You should check him out before you buy another one. Theyre not the same battery.

Yes, I saw the same follow up video. But, my neighbor and I are so pleased so far with our Weize 100AH batteries that I may still chance it. 350 bucks compared to 900 to a 1000 is something to think about.

[Lowerider58]

Yes, I saw the same follow up video. But, my neighbor and I are so pleased so far with our Weize 100AH batteries that I may still chance it. 350 bucks compared to 900 to a 1000 is something to think about.

The current ones may still be as good but only time will tell. So far I’m very pleased with the one I have now. I’m running 3 Garmin graphs and Livescope and can easily fish 2 days with them.

[bassfisher444]

Trolling motor on it's own batteries, always no matter what type they are. If you want a cheap upgrade that will give you much longer run time get 2 group 29 Everstarts from Walmart.Or you can put all your electronics on the cranking battery.

[Highcentered]

I have been involved in 1 1/2 instances using DC Buck converters.
1) I helped a local Crappie Guide reduce his battery count and weight by replacing lead acid with Lithium. We eliminated a stand electronic battery by using a 24/12 buck transformer. It worked out ok: No interference.
1/2) I helped another friend rig up his aluminum river boat with a 36 volt TM removed from his glass boat. He needed 12 volts for his LiveScope and another battery was not an option so we are using a buck transformer. He just finished the install and has not had a chance to try it so we don’t know about interference.

I recommended the one shown because it could handle the 36 volt primary voltage.

This really interests me. I'd rather do this and a small cranking battery over getting another 75lb cranking battery when the one I have now dies. My two 60a lithium batteries have more than I'll ever need for a trip. I'm guessing the transformer also helps cut down on interference?