What size Lithium Batteries are you guys using on your Merc 250 Pro XS?
Motor 1B723033...Since the Weize 12V 100Ah Lithium LiFePO4 trips the BMS every time I try to start the motor, what ones, are you guys with Merc Pro XS 250, being used? Weize rep states it not meant for a starting battery, but didn't state that in their ad, just Marine use...searched but results were scattered...some stating 100Ah were fine but different manufacturers...so, looking for some input from current user of Lithium batteries...thanks in advance guys, Jim.
Last edited by Ranger Z522; 05-23-2023 at 05:35 PM.
Merc hasn't approved lithium for optimax motors, I did a lot of research and talked to some fishing buddies and ended up getting the 125ah ionic. I've had it for over a month and have no complaints. So I can't give a long term review. I keep an eye on voltage regularly and have a jump switch to a trolling motor battery that will start the motor as a backup. But the bms in the ionic 125 is good. Talk to Andy at drewcraft(sponsor)
Chris Hawkins
Ranger 520VX / Mercury Optimax 225
Chris, I thought I read on the Merc update, my Pro XS was approved?..I believe the 3rd line had it included??....buddy has that 125Ah in his 200 SHO, no prob...thanks Chris!.
The 150 4strokes are 3.0L motors including the 150 proxs 4s.
Chris Hawkins
Ranger 520VX / Mercury Optimax 225
Chris, I thought my 250 was 3.4 v6 pro xs in 3rd line??...-4.6L V8 and 3.4L V6 175-300hp Fourstroke, ProXS, SeaPro and Verado Models..
That chart is hard to read and comprehend. I’m using an Ionic 125 and have had zero issues. I’ve monitored the battery charging rate with the Ionic app and haven’t seen any issues with the charging rate demand on the alternator since the 2 strokes 250 ProXS’s don’t have the most robust charging system. The BMS on the Ionic 125 is designed to handle the higher demands of cranking. So far, all is good.
Your 250hp Optimax ProXS is a 3L 2-stroke. Mercury has not approved use of lithium for any 2-strokes at this time.Originally Posted by Ranger Z522
"ProXS" is not an engine identifier and was available model in the 1.5L, 2.5L, & 3L Optimax lineup at least a decade before the new 4-strokes were released.
From the battery topic in the FAQ at top of this forum, red text applies:
As of 12/23/2022, Mercury has issued Service Bulletin 2022-19 and SHS 2022-21 stating that the listed engines will be permitted to use a Lithium Iron Phosphate Battery that is designed for engine cranking, as long as it meets the listed specifications:
-2.1L 75-115hp Fourstroke, ProXS and SeaPro Models
-3.0L 150hp Fourstroke, ProXS and SeaPro
-4.6L V8 and 3.4L V6 175-300hp Fourstroke, ProXS, SeaPro and Verado Models
-2.6L L6 200-400 Pro and Verado Models
-7.6L V12 500-600hp SeaPro and Verado Models.
-ALL MERCURY RACING OUTBOARD ENGINES (Current Production models)
-NO other engines approved at this time.
_______
Phil
'09 Hewescraft ProV
'09 150 Optimax
If you would have asked first or at least contacted one of our BBC sponsors, you would’ve got a battery that worked. Tough lesson to learn.
USN Retired
2020 Basscat Caracal
2020 Mercury 225 ProXS 4s
Thanks Phil, didn't realize that...06, I did glance through sponsors on my phone and missed them...hind sight...lessened learned...thanks for your insight sir...
Nope. Specific 4-stroke products only.
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 47 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
-3.0L 150hp Fourstroke, ProXS and SeaPro
This is the line that confuses most including me!
Burnt into my ol gray matter now...lol..and thanks for your input bhjr!..
I have been running a 125 ionic for couple of years, great battery and it does a fantastic job. We also put one on a 1995 pro max 225. Thought it would be safe with the dual voltage regulators. It has, no issues what so ever. Have several friends using them crappie fishing, all have 250 2 strokes, work amazing. Seems the new electronics keep the charge levels down with enough currant draw to hold battery below 100% all the time. I know I can turn on all my graphs, radio etc in am, by the time I leave and buzz down the lake, which doesn’t take me long, I am near 95%, all golden
Ron Fears
Stroker/300XS
1E003823
Thanks DewRon!..✌️
Mercury's designation for current non Pro-XS and SeaPro models in all hp ranges is "FourStroke" (excluding racing, Verado, and diesel).
https://www.mercurymarine.com/en/us/engines/outboard/
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Phil
'09 Hewescraft ProV
'09 150 Optimax
Or to make it even less confusing: "If it's a Fourstroke... it goes in the Fourstroke Forum". Anything from 2.5hp - 600hp Outboards, and any of the Sterndrive Products that scatter in from time to time.
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 47 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
125 Ah Ionic will work fine on a 2-stroke 250 HP Mercury
I have been running a Ionic 125 ah this year so far it has been all I was told it would be.
04 521VX 250 Pro XS
14 521C 250 Pro XS
Thanks Savage and bass.man!..✌️
Just for curiosity sake,with that battery what voltage would you expect to see from the solenoid to the starter? I was having an issue with no start so I checked mine and got 13.4 at the hot side before starting, and 8.5 volts when turning the key. I thought it would be more.
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