Battery and charger

[Buster]

I don’t have access to my manuals but suspect the same. Does it mention wire size to use? Just thinking out loud. I’d assume it would go into charge mode. The charged battery is going to supply current up to its max, usually around 70A. Charge rates run from 25-50% of ah capacity. Not sure if the BMS will limit that current. The BMS programming is usually unique to each mfg. So, I’m am curious to what happened right after the reset.

Yeah, fair to be concerned with your specific battery and BMS. Wire size was not suggested in any way. I believe the BMS "talk" to each other and start balancing cells. No, it did not dump at max amps. In fact, I did not see any large current flow on my monitor. Don't recall details, but I wondered the same thing.

 

[Still Afloat]

I have a minn Kota trolling motor 24lbs thrust it’s a little older but works great. I know I need a 27 deep cycle battery but not sure what kind of charger I should buy for it. My boat is just a 14ft aluminum boat so only the trolling motor will be using the battery and maybe a couple times a week at the most so I’ll be charging the battery at home after every trip. I’m just not sure what kind of charger I should get if anyone has any knowledge to share or recommendations much appreciated.

Hey Boogman, does that motor have have electronic speed control (ESC) or is it one of the older units with the resistor speed control? Minnkota refers to the ESC as a “Digital Maximizer.” The resistor type is just called, “adjustable speed control.”

The reason I brought this up is the non-ESC motors will discharge the battery much faster and you may need to oversize the battery in this case. If it has the “Digital Maximizer” a 50 A/hr LiFePO battery is plenty. If not, a 50A/hr will still work but a 100 A/hr will provide better run times.

At this this point the LiFePO batteries are similarly priced to lead acid, they perform better and they are a lot lighter. The only reason that I’d buy a lead acid deep cycle trolling battery at this point is if I did a lot of winter fishing and the battery was not easy to remove from the boat for charging at above freezing temps.

 

[airshot]

All this info is great stuff, thanks !! I did look up Thills battery of choice and they do make a 140 ah for 269 bucks. Might be just what I need. As I get older, I am finding I don't stay out on the water as long, better to go another day than to spend 8 hrs on the lake it seems. Thinking a single 100 just might do the job afterall.
Regarding chargers, my R/C chargers wake up my lipo's after a long set. Doesn't these chargers for these boat batteries do that ??

 

[Buster]

All this info is great stuff, thanks !! I did look up Thills battery of choice and they do make a 140 ah for 269 bucks. Might be just what I need. As I get older, I am finding I don't stay out on the water as long, better to go another day than to spend 8 hrs on the lake it seems. Thinking a single 100 just might do the job afterall.
Regarding chargers, my R/C chargers wake up my lipo's after a long set. Doesn't these chargers for these boat batteries do that ??

Some chargers do, some don't. NOCO doesn't. Pro Mariner and MinnKota digital do. May be others, these I know about.

 

[airshot]

Some chargers do, some don't. NOCO doesn't. Pro Mariner and MinnKota digital do. May be others, these I know about.

Is there a particular name or description of this feature that I should look for ?? My R/C chargers just say soft start for stored batteries.

 

[Buster]

Is there a particular name or description of this feature that I should look for ?? My R/C chargers just say soft start for stored batteries.

Not sure, airshot. My main battery manufacturer (Amped Outdoors) lists recommended chargers. I also picked up a 50Ah TimeUSB battery during the Prime sale ($105 shipped!) that I'm using for my accessory battery since I've added some amperage with upgraded finder and live view. Thill's info should cover that.

 

[thill]

Thanks for that info....I will be switching from my current dual group 31 lead acid to Lifepo4 when these give up. Will one 100ah lifepo4 do the same job that my two current Batteries do on my 12v 55# trolling motor or do I need two lifepo4 batteries. My research has not showed much real world experience in their comments.

Sorry for the late reply, but it depends on your use... In MY case, a single 100AH has been very similar to two Group 29' LA batteries. (I don't have 31's)

With a MK Riptide ST 55#, pushing my 16' Deep V Spectrum...

• I can go several days on a single charge on the lake, working grass beds and docks.
• In the Bay or rivers, with swift currents, where the motor is running almost constantly, I can go 8 hours without an issue. I'm not sure how long it will go, to be honest. I have never had the BMS shut it down during a trip, and I always have a second battery just in case, but have never needed it.

With a MK Riptide SP 70#, pushing my 22' center console...

• With (2)100AH, I've done long, sunup to past sundown trips of 12+ hours in heavy tides and the batteries never flinched. Again, I have no idea of how much longer they would have gone. Went back to the hotel, plugged in the little 10A chargers and 6 hours later they were ready for another long day. Impressive, to me. My group 29's would have wound down by the early afternoon.
• In the lake, they don't even get touched in capacity. I could probably fish for a week without recharging, but I am not a guy who fast trolls all day long. Even if I were, I could still probably go 2 days, but that is just a guess.

Overall, real world, I would say brand-new 108AH lead acid deep cycle batteries are about 60% of the 100AH TimeUSB. After a year, that probably drops to 50%, and so on, but again, that's just a guess.

My poor LA batteries are getting neglected since I made the switch! I charge them up every once in awhile to keep as backups, but I probably should just give them to someone or sell them. I doubt I'll ever go back.

 

[thill]

...I also picked up a 50Ah TimeUSB battery during the Prime sale ($105 shipped!) that I'm using for my accessory battery since I've added some amperage with upgraded finder and live view. Thill's info should cover that.

I love my 50AH, it's so small and light. I run a Livescope and an Ultra 106, and they run for days on a single charge.

I also use it with a 750 watt inverter for misc. things, including air and water pumps, chargers and playing bee videos on a 32" TV at the Farmer's Market over the weekend when selling honey. It ran 4 hours straight, and never flinched. I wish I had checked the charge level afterwards, as I thought it would have died after an hour or two. I was wrong, which was a good thing.

That battery seems comparable to a Group 29 battery, but I would need to do some testing before I can say that with conviction.

 

[Buster]

My poor LA batteries are getting neglected since I made the switch! I charge them up every once in awhile to keep as backups, but I probably should just give them to someone or sell them. I doubt I'll ever go back.

I turned the old Lead Acid battery into the backup battery for my sump pump. Perfect use.