Lithium 100 ah battery

[Jethro]

Aren't they under warranty?

Interstate covers marine deep cycles for a year and then nothing. I bought all three of these 13 months ago

[lowaccord66]

Jethro from my experience, you likely have a bad ground.  Do you have a breaker on your power?  You should for these for several reasons.  Are you using a barrel connector to connect/ disconnect power to the unit? 

Also Jethro I used to run the cheapest deep cycles ever with a 12v 55lb thrust unit.  2 group 34's, rv batteries from tractor supply. Would spot lock for 8-10 hours in total per day and never killed the batteries.  I'm not using expensive agm's now and have literally been spot locked for more than 6 hours on a single reef.

[swnoel]

Interstate covers marine deep cycles for a year and then nothing. I bought all three of these 13 months ago

That sucks!! I'd still try and get them to cover it... you have nothing to lose!

[Jethro]

Jethro from my experience, you likely have a bad ground.  Do you have a breaker on your power?  You should for these for several reasons.  Are you using a barrel connector to connect/ disconnect power to the unit? 

Also Jethro I used to run the cheapest deep cycles ever with a 12v 55lb thrust unit.  2 group 34's, rv batteries from tractor supply. Would spot lock for 8-10 hours in total per day and never killed the batteries.  I'm not using expensive agm's now and have literally been spot locked for more than 6 hours on a single reef.

I have a 60amp breaker and the motor is all hard wired except for the actual plug for the motor which is a brand new Marinco 70 amp plug specifically for 36v motors. When I installed all the batteries I cleaned the contacts and wires so good I could see my reflection in them. There aren't any barrel connectors or crimped connectors in the system at all. I also have 6ga wire coming from the 3 batteries directly into the plug which is due to the 10 foot run on either side of the series. I can't see how I have a bad ground but it's possible. Keep in mind that the performance dropped significantly last year, and the whole system has been reinstalled since then because my motor and the batteries came inside the house over the winter.

Last year I was able to autopilot troll for 10 hours easy. Even once when I was remote camping I did exactly that and still trolled the following morning for about 4 hours. But doing the math from MinnKota my motor probably draws 20 amps an hour on average doing that. So theoretically it's only good for 5 hours with my 105ah batteries. I believe I have deep discharged my batteries WAY too much and cooked them, but maybe I am wrong. I checked all the water levels, that is fine. When I got back from haddock fishing the other day where the Ulterra shut off presumably due to low voltage and then failed to stow, I plugged in my 3 bank MinnKota Digital charger and it went from fully discharged batteries to full charge in about 2 hours. That doesn't seem right. It also seems that the battery gauge built into the MinnKota GAINS power as I use it. So I'll start the day with a fully charged bank of batteries (supposedly) and the MinnKota says it's at 50%. An actual voltmeter shows 12.76 volts on all my batteries. Then as I use the motor, 3 hours later it showed 75% on the MinnKota gauge. Then an hour later it died and wouldn't stow. I wish I brought my voltmeter on the boat with me, but when I got home 3 hours later the batteries were reading 12.3 volts. The biggest thing that gets me thinking I torched the batteries is that the motor is supposed to shut down before the voltage gets too low to stow the motor.

Tonight I am going to do the horrible task of pulling all the batteries out of the boat. I'll bring them to Interstate in Nashua and have them check them.

Other than deep discharging the batteries I took super good care of them. They came inside over the winter and were on battery tenders. Last year I always charged them as soon as I got the boat back home.

That sucks!! I'd still try and get them to cover it... you have nothing to lose!

Oh yes, I'm going to do my best. This cost me $530 just last year and I bought them at the Interstate Factory Store:

[Mac Attack]

Geoff - LiFePo2!!!

Quit BS’n around.   

Yea, LA batteries should never be drawn down past 50% or they degrade.  Each time you do this.  But we all do this!!

The LiFePo2 batteries can be drawn down.  And if you don’t draw them down, the allowable recharge cycles increase.  This is why I decided on 200ah instead of 100ah. 

[Jethro]

Geoff - LiFePo2!!!

Quit BS’n around.   

Yea, LA batteries should never be drawn down past 50% or they degrade.  Each time you do this.  But we all do this!!

The LiFePo2 batteries can be drawn down.  And if you don’t draw them down, the allowable recharge cycles increase.  This is why I decided on 200ah instead of 100ah.

I really just thought that deep discharging would just lessen my total recharge cycles rather than capacity. That I can live with- sorta. But I think it's killed the capacity, bad. I don't know yet.

Believe me! I am doing LiFePo2 ASAP!! But it's not in the budget for 2021 for $2,100.00 to do the 100ah option, let alone the $3800 or whatever it is for the 200ah option.

Hoping that Interstate takes pity on me and replaces the batteries. If not I will buy 3 of the cheapest group 31's I can find for the remainder of this year and next season I will have a 200ah lithium- as long as your experience goes well, Mac!

[Mac Attack]

Sam’sClub
I bought the Duracell 31’s for $99 each

And my 200ah LiFePo2 was $1600 plus $400 for shipping.

[Jethro]

Sam’sClub
I bought the Duracell 31’s for $99 each

And my 200ah LiFePo2 was $1600 plus $400 for shipping.

Oh wow, I thought the 200ah would be way more expensive. I just emailed Jeff again. If it's $2k to get it to me, I may go that route.

[Mac Attack]

Oh wow, I thought the 200ah would be way more expensive. I just emailed Jeff again. If it's $2k to get it to me, I may go that route.

Here is where I bought it -

https://www.lithium-battery-factory.com/product/36v-200ah-lithium-rv-batteries/#body_sele


Email Carl Wu @ [email protected]

Carl is super!
Very highly regarded by others on the lithium battery boards.
He is making it right for me, even though FedEx is only going to reimburse them $100 for the lost battery.
His English is great, at least his written English.
Very easy to understand and he is very good technically.
He can answer your questions.
Send him an email and good luck.

[lowaccord66]

Agm for me.  They work.  They can deep discharge and while I could afford the lithium I am uninterested in the pricing.  Not to mention if you accidently puncture one of those lithium batteries in any manner your rig goes up in flames.  Low chance but if it happens that's what you can expect...

Jethro if you go Mac's route I want to hear all about it...and the challenges.  God bless you Mac, back yard battery builders...made me laugh.

[Mac Attack]

Agm for me.  They work.  They can deep discharge and while I could afford the lithium I am uninterested in the pricing.  Not to mention if you accidently puncture one of those lithium batteries in any manner your rig goes up in flames.  Low chance but if it happens that's what you can expect...

Jethro if you go Mac's route I want to hear all about it...and the challenges.  God bless you Mac, back yard battery builders...made me laugh.

Nope!
AGM are LA batteries.
Discharge below 50% and they go to nuts.

[jeffmac85]

Just an FYI, 100ah versions in both 12V and 36V (I would think 24V also but I didn't check) are available through amazon for roughly $1400-$1500 depending on 1 36V vs 3 12V and the brand you buy.  Most all have free shipping and of course are purchase protected through Amazon.  These batteries are definitely coming from China, but for those of you dead set on an American based company you may be surprised to find the cells they are using are from China or some other Asian country or India.  All of these lithium ion cells are being produced over there due to the labor laws and environmental laws being almost non existent.  The cost to manufacture these in the US due to recycling issues is astronomical.  So all of these American companies (Dakota lithium, battle born etc) are all using foreign made cells, just assembling and top/bottom balancing and building the battery here in the US.  And honestly anyone with half a brain can do all that, I've looked into it.  However even building it myself I was only looking at saving 25-30% over Carl's cost so its almost not worth it, or at least it wouldn't have been if fedex hadn't dropped the ball.

[Jethro]

Mac, the research I've done shows AGM is slightly more resistant to deep discharge, you can discharge to 20% of capacity rather than 50% of capacity without damaging them. May fall under the "I read it on the the internet so it must be true" category though.

All my batteries are in the back of the truck today, I'll bring them to Interstate this afternoon and see what they say.

[swnoel]

Mac, the research I've done shows AGM is slightly more resistant to deep discharge, you can discharge to 20% of capacity rather than 50% of capacity without damaging them. May fall under the "I read it on the the internet so it must be true" category though.

All my batteries are in the back of the truck today, I'll bring them to Interstate this afternoon and see what they say.

Are those AGM batteries? Something isn't right. I have an Interstate regular deep cycle battery in my dump trailer and plugged in the onboard trickle charger for 24 hours and was surprised even though it showed a full charge, it was only 47% on my portable charger. I pulled the battery and charged it on a real charger. How long was it on the Minn Kota charger?

[lowaccord66]

Nope!
AGM are LA batteries.
Discharge below 50% and they go to nuts.

Has not been my experience at all.  Keep in mind all I do is spot lock for 8-12 hours a trip....over and over and over again.  Ive even discharged to nearly zero getting my boat back to the launch with the troller when the main died.  No issues and these are cheap cabelas agm's.   

Now I've been watching the guys on tiny boat Nation play with electric only boats...check it out Mac...they are using very specific battery setups to run a 40hp electric outboard and how they are doing it should be noted.  They are not using mail order batteries haha...