Mega live/ deep cycle recommendation

[stk44]

With the deep discounts on mega live 1 coupled with mega live 2’s lack of compatibility with my helix fish finders, I decided to pull the trigger on a mega live 1. Currently I have an interstate AGM group 31 dual purpose 100aH battery. I will be running everything other than the trolling motor on this battery( 2 helix 10’s, ML1, bilge/auto bilge, nav lights, livewell pumps, etc).

Questions #1 is, will this battery be able to handle the accessories for 8-10 hours?
Question #2. I’m looking for a separate house battery. Does anyone have affordable lithium battery recommendations? I was looking at the “LiTime 12V 100Ah Self Heating LiFePO4 Lithium Battery”. It’s less than $300, but does anyone know if this is comparable to any of the big names like Dakota or similar? Is there anything I should look for/ start away from in my search?

 

TIA,

steve 

[Tennessee Boy]

Personally, I would not hesitate to buy the LiTime battery.  These batteries are pretty simple.  They are all made with the same Chinese cells.  Dakota spends more on advertising and seems to have bad reputation when it comes to service.  Why pay $500 more for that?

 

I'm not sure I would go with the heated battery unless you fish a lot in the winter and the temperature stays below freezing for days where you charge your batteries.

[casts_by_fly]

A group 31 is nominally 100 ah. But the low voltage cutoff for a humminbird is nominally 10.4v which is around the 80% mark on a lead acid. So best case you’ve got 80 ah and practically speaking you don’t want to push it that low. The helix pulls 2.7A each and the mega live is another 2A. So you’re at 7.4A. 10 hours would be 75ah which is your battery spent. If you need it to do other things then you’re out of luck. 
 

I wouldn’t hesitate to go with litime either. In fact I just put two in the new boat build. I went 100ah dedicated for two explor units and ml2. It should be enough for a full day, but I’m not doing more than an 8 hour day. It’s also dedicated and if I kill it I’m only out my fish finder. 

[stk44]

33 minutes ago, Tennessee Boy said:

Personally, I would not hesitate to buy the LiTime battery.  These batteries are pretty simple.  They are all made with the same Chinese cells.  Dakota spends more on advertising and seems to have bad reputation when it comes to service.  Why pay $500 more for that?

 

I'm not sure I would go with the heated battery unless you fish a lot in the winter and the temperature stays below freezing for days where you charge your batteries.

Thanks for the info. Im not sure I saw an option for a non heated one, but I likely won’t need it. I live in pa and my unheated garage likely will not go below freezing. I think I will go this route soon, but now I gotta figure how to wire everything lol. I’m thinking a perco switch and want to run a fuse panel to the starboard rod locker to run the graphs and ML1. 

[casts_by_fly]

2 minutes ago, stk44 said:

Thanks for the info. Im not sure I saw an option for a non heated one, but I likely won’t need it. I live in pa and my unheated garage likely will not go below freezing. I think I will go this route soon, but now I gotta figure how to wire everything lol. I’m thinking a perco switch and want to run a fuse panel to the starboard rod locker to run the graphs and ML1. 

look on amazon if you aren’t already. There is the basic 100ah for $209 and the Bluetooth version for $30 more. 

[Tennessee Boy]

1 minute ago, stk44 said:

Thanks for the info. Im not sure I saw an option for a non heated one. 

Most batteries are not heated.  You may be confusing "low temp protection" with a heated battery.  Low temp protection just means it has an internal temperature sensor and if the temperature drops below freezing it will shut off charging.  On Amazon the heated battery is $299 and the non heated battery is $239.

[stk44]

31 minutes ago, casts_by_fly said:

A group 31 is nominally 100 ah. But the low voltage cutoff for a humminbird is nominally 10.4v which is around the 80% mark on a lead acid. So best case you’ve got 80 ah and practically speaking you don’t want to push it that low. The helix pulls 2.7A each and the mega live is another 2A. So you’re at 7.4A. 10 hours would be 75ah which is your battery spent. If you need it to do other things then you’re out of luck. 
 

I wouldn’t hesitate to go with litime either. In fact I just put two in the new boat build. I went 100ah dedicated for two explor units and ml2. It should be enough for a full day, but I’m not doing more than an 8 hour day. It’s also dedicated and if I kill it I’m only out my fish finder. 

Do you happen to know, generally speaking, how many amps the “other accessories” draw? The livewell pump is on a timer and the nav lights aren’t on all the time, etc. just wondering how much more I really need? Also I thought I’ve read elsewhere the mega live 1 was more like 1 amp? Thanks again! 

4 minutes ago, casts_by_fly said:

look on amazon if you aren’t already. There is the basic 100ah for $209 and the Bluetooth version for $30 more. 

Wow. That’s way cheaper than I thought. Thanks!

3 minutes ago, Tennessee Boy said:

Most batteries are not heated.  You may be confusing "low temp protection" with a heated battery.  Low temp protection just means it has an internal temperature sensor and if the temperature drops below freezing it will shut off charging.  On Amazon the heated battery is $299 and the non heated battery is $239.

Ah okay, got it. I can probably go for the $239 one then. I’ll probably limp by with my current battery until I either A run into issues or B have some time free up where I can install the battery and wire everything the way I want it. 
 

thanks! 

[casts_by_fly]

33 minutes ago, stk44 said:

Do you happen to know, generally speaking, how many amps the “other accessories” draw? The livewell pump is on a timer and the nav lights aren’t on all the time, etc. just wondering how much more I really need? Also I thought I’ve read elsewhere the mega live 1 was more like 1 amp? Thanks again! 

Wow. That’s way cheaper than I thought. Thanks!

Ah okay, got it. I can probably go for the $239 one then. I’ll probably limp by with my current battery until I either A run into issues or B have some time free up where I can install the battery and wire everything the way I want it. 
 

thanks! 

yeah, for $200 it’s pretty much a no brainer. 
 

you’d have to look up your other equipment but I can’t imagine you’d need more than 5 ah since they aren’t constantly running. 

[stk44]

2 minutes ago, casts_by_fly said:

yeah, for $200 it’s pretty much a no brainer. 
 

you’d have to look up your other equipment but I can’t imagine you’d need more than 5 ah since they aren’t constantly running. 

You are saying 5amps for the other accessories to cover an 8-10 hour period of time, right? When I was guesstimating, I thought 1 ah sounded conservative to run all my other accessories. 
 

[casts_by_fly]

7 hours ago, stk44 said:

You are saying 5amps for the other accessories to cover an 8-10 hour period of time, right? When I was guesstimating, I thought 1 ah sounded conservative to run all my other accessories. 
 

that was my purely speculative guess without digging.  I just did a quick google search and a livewell pump seems to be around 3 amps.  On an 8 hour day continuous that’s 24 ah but you’re not going to run continuous. If you’re on a 1 minute on, 5 off timer that’s 4 ah total. That’s more than I had in my head but still not a ton.  Led lights are negligible and you only have them on in the dark. The bilge shouldn’t be running unless it’s raining all day. It will be a similar draw to the livewell but won’t be running as much (I hope!).  

[stk44]

Is it possible to have a standalone electronics battery hooked up to the same on/off kill switch that my starting battery is on? I was thinking if I bought a new switch that has the option for both batteries off/on or 1 off, 1 on would work. From there I would run 8 gauge wire up to the starboard side rod locker which would connect to a fuse panel to power my 2 graphs, 5 port switch, and ML1. Does that sound like that would work? 

[casts_by_fly]

you'd need two switches for two batteries.  Otherwise you'd be hooking them together via the switch.  There might be switches that have two switches built in to the same switch, but I haven't looked.

 

 

[Junger]

14 hours ago, stk44 said:

You are saying 5amps for the other accessories to cover an 8-10 hour period of time, right? When I was guesstimating, I thought 1 ah sounded conservative to run all my other accessories. 
 

 

I think the 2.7A Helix draw is at 100% brightness. You can do a lot of things to extend the battery time with your 100AH AGM, like turning down your brightness to 60%, or even putting them into standby when not being used as well.

[Tennessee Boy]

2 hours ago, stk44 said:

I was thinking if I bought a new switch that has the option for both batteries off/on or 1 off, 1 on would work.

I assume you're talking about a switch like the one in the link below.  Yes it would work but selecting "All" effectively wires the two batteries in parallel.  It's a bad idea to run a lithium and a AGM in parallel.  It wouldn't hurt to do it for a couple of seconds while you switch but I would be concerned about accidentally leaving it that way so I would not use that switch.  You could get a similar switch without the "All" option that would let you switch back to your cranking battery if your house battery fails.

 

https://www.overtons.com/perko-battery-selector-switch-314474.html?objectID=314474&queryID=6821487e6d0f51ff587553d514d8c328&indexName=production_na01_campingworld_demandware_net__Overtons__products__default

[stk44]

1 hour ago, Junger said:

 

I think the 2.7A Helix draw is at 100% brightness. You can do a lot of things to extend the battery time with your 100AH AGM, like turning down your brightness to 60%, or even putting them into standby when not being used as well.

Thanks. I’ve thought about that and that’s a great idea. Now that I have mega live and only 1 10” screen, I won’t have a need for any side imaging that I share from my console unit. I’ll keep the console in standby and see what I can do about the brightness on the bow. The bow graph is flush mounted and I have a tinted graph glass, which might complicate things. 

1 hour ago, Tennessee Boy said:

I assume you're talking about a switch like the one in the link below.  Yes it would work but selecting "All" effectively wires the two batteries in parallel.  It's a bad idea to run a lithium and a AGM in parallel.  It wouldn't hurt to do it for a couple of seconds while you switch but I would be concerned about accidentally leaving it that way so I would not use that switch.  You could get a similar switch without the "All" option that would let you switch back to your cranking battery if your house battery fails.

 

https://www.overtons.com/perko-battery-selector-switch-314474.html?objectID=314474&queryID=6821487e6d0f51ff587553d514d8c328&indexName=production_na01_campingworld_demandware_net__Overtons__products__default

Yes that is the one I’m referring to. Hmm, so if I rig it this way, I would have to constantly switch between batteries, right? Maybe i’d better stick with two switches.does it matter if i rig the switch in the battery compartment at the back of the boat or run it all the way up to a rod locker?  

[Tennessee Boy]

1 hour ago, stk44 said:

Yes that is the one I’m referring to. Hmm, so if I rig it this way, I would have to constantly switch between batteries, right? Maybe i’d better stick with two switches.does it matter if i rig the switch in the battery compartment at the back of the boat or run it all the way up to a rod locker?  

I'm not sure I'm following your thinking.  You would have your motor connected to your cranking battery.  You would have separate wires running from your cranking battery to the B side of the switch.  You would have your house battery connected to the A side of the switch.  The switch output would be connected to your fuse boxes which power all of your electronics and accessories.  You would leave the switch on A so your house battery powers all this stuff.  If your house battery fails then you would turn the switch to B so your cranking battery would power your accessories in addition to cranking your motor.  I would not expect to change the switch very often if ever.  You would still want a main breaker switch between the house battery and the switch.  If you currently have a switch on your cranking battery then you would leave that in place.

[stk44]

1 hour ago, Tennessee Boy said:

I'm not sure I'm following your thinking.  You would have your motor connected to your cranking battery.  You would have separate wires running from your cranking battery to the B side of the switch.  You would have your house battery connected to the A side of the switch.  The switch output would be connected to your fuse boxes which power all of your electronics and accessories.  You would leave the switch on A so your house battery powers all this stuff.  If your house battery fails then you would turn the switch to B so your cranking battery would power your accessories in addition to cranking your motor.  I would not expect to change the switch very often if ever.  You would still want a main breaker switch between the house battery and the switch.  If you currently have a switch on your cranking battery then you would leave that in place.

Sorry for the confusion. I was thinking I could replace my on/off switch with the switch you sent me a link for. I see now that wouldn’t make sense. 
 

I obviously have a lot more to research, but if I understand correctly, I need:

- battery

-breaker between battery and switch (do you know what kind and how many amps? 20?)  

-switch 

-fuse panel 

 

Is my thinking correct here:

1. positive lead (8 ga) would go from the positive battery terminal to the battery side of the switch. with a breaker in between the battery and switch 

2.power wire for fuse box (10 ga?) would go back to the switch 

3. ground wire for fuse box goes back to negative battery terminal 

thanks for your help