JoeS
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Re: 12v Battery - All You Ever Wanted To Know

Thu Nov 25, 2021 12:27 pm

PV1 wrote:...I forget how long mine lasted, but I got at least 7 years out of them. My old Cavalier battery lasted 10 years.
The problem nowadays for all cars is that they have various car systems drawing a miniscule amount of current from the 12v battery, gradually depleting it. With our i-MiEVs it's the alarm, doorlocks, and Remote, to name a few. It's this repetitive down-and-up cycling that affects the life of the lead-acid battery. The older they get and the longer we go between drives, the more liable we are to experience a hiccup. Pity that our i-MiEV doesn't monitor the 12v battery and automatically wake up to activate the dc-dc when it goes low.

That's still not bad, as, when parked, my old Tesla draws anywhere between 0.4A and 1.7A from the 12v battery depending on the display settings, and the newer Teslas with Sentry mode and cameras are far worse - the saving grace being that the car monitors the 12v battery voltage and wakes up the big battery's dc-dc to recharge that 12v battery whenever it drop to ~12.2v. That's why I always attach a float charger (actually, a small Meanwell power supply set to the AGM manufacturer's recommended float of 13.7vdc) to the Tesla's 12v battery even if I'm not using it for only a day. My Tesla 12v is now going on six years... (knock on wood!), significantly better than average for Teslas.
EVs: Two '12 Wht/Blu SE Prem., '13 TeslaMS85, three 156v CorbinSparrowsLi(NMC), 24v EcoScoot(LiFePO4)
EV Conversions: 156v '86 Ram PU, 144v '65 Saab96, 48v1kW bike
RIP(2021) ICE: Orig.Owner '67 Saab96V4, '88 IsuzuTrooper; '76 MBZ L206D RHD RV

Mitsi
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Joined: Tue Jan 09, 2018 5:24 am
Location: Toronto, ON.CA

Re: 12v Battery - All You Ever Wanted To Know

Thu Nov 25, 2021 1:20 pm

I just bought a Noco NLP30 Lithium Ion battery which allegedly has a built-in BMS. Yet in their manual they specify using a Lithium Ion battery charger. The charge voltage is specified at 14.6V and max charging current of 24A. Any objections to dropping this puppy right in there and letting her charge it herself? Our 12V lead/acid is on it's last legs and I thought this would be a great idea, until I RTFM. :|
https://no.co/products/lithium/powersport

Matt

JoeS
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Re: 12v Battery - All You Ever Wanted To Know

Fri Nov 26, 2021 3:03 am

Hey Matt - "Mitsi" (that's what I named our first i-MiEV), welcome to the forum.

Good question, and one I've been mulling over as I've built my own LiFePO4 battery but haven't installed it yet as I'm still tinkering with the BMS.

I looked over the specs of the NOCO NLP30 LiFePO4 battery and here are my thoughts -

1) Cell balancing
Their description sounds impressive and it looks as though they have continuous active balancing. I wouldn't worry about it as it's in their best interest to keep those cells balanced no matter what you do.

2) Overvoltage protection
Presumably by opening the connection. Edit: this voltage is probably slightly above 14.6v, which is high already. You'll never see it as the i-MiEV dc-dc is 14.4v (or a bit less in hot weather). Besides, they say it recovers when an external load is applied.

3) Undervoltage protection
Again, presumably by opening the connection. I doubt if you'll ever get there, certainly not when driving unless there's a fault in the i-MiEV. It might happen if you leave the car parked without a float charger for a few weeks. They say it recovers if you put it on a charger.

4) Charging Voltage
They say 14.6v but that's already rather high (edit: actually at the absolute upper voltage limit) for LiFePO4, so the i-MiEV's 14.4v (or a bit lower) will be just fine, as long as the NOCO cells remain balanced. I normally charge my LiFePO4 cells to 3.4v (x4= 13.6vdc) edit: as that's close to the charging knee above which there's not much energy.

5) Battery Capacity
They say 8Ah (and even say 32Ah lead-acid equivalent) so you'll be just fine as long as you don't let the car sit unused for more than a couple of weeks, and just put a float charger on it if you do.

6) Overcurrent Protection
They say it will recover when the external load is removed, but they don't say what happens if the maximum 24A charging current is exceeded; however, they also spec a continuous discharge current of 80A, so whatever protection they have will still allow that much current to go into the battery.

7) Maximum Charging Current
This 24A spec is the only one I might be concerned about, as the i-MiEV dc-dc has the ability to feed a discharged NOCO with a higher current. Since the i-MiEV supplies a constant regulated voltage I suspect that the battery current will be self-limiting as soon as its voltage has reached that 14.4v voltage limit. In any case, be sure to have a fully charged NOCO when you first install it, which should minimize any initial high current. Since you're in a continuous-use scenario when you're driving, I don't see a problem as the dc-dc will simply keep the voltage constant and the battery will just sit there floating. The problem occurs if you've not driven the car and allowed the battery to be discharged by the i-MiEV's vampire loads. They don't say what happens if you exceed 24A charging current - I'd be inclined to call up NOCO and ask them, but be sure to tell them that the voltage is constrained to 14.4vdc max.

8) Terminals
I see that the polarity orientation matches the i-MiEV OEM battery; however, in order not to butcher the connection, you might consider a terminal adapter, something like this - Edit 1 Dec.2021: the shorter post with M6x1.0 screw that comes with the post fits perfectly!

https://www.amazon.com/XS-Power-580-Adaptor-Thread/dp/B004XH67B2
Edit: or maybe this taller post (check the NOCO dimensions for best fit):
https://www.amazon.com/XS-Power-586-Adaptor-Thread/dp/B004XH69MY

9) Low Temperature
LiFePO4 don't like being charged at low temperatures, and they spec -10°C as their lower limit. Edit: This IS a major problem in your part of the world - see subsequent discussions, especially http://myimiev.com/forum/viewtopic.php?f=23&t=3067&start=60#p44032 Hopefully you have a garage that doesn't get that low. In NOCO's User Guide they say it recovers when it gets back to in-spec temperatures, but doesn't say if it cuts out by going open circuit. They simply say the BMS doesn't allow charging below -10°C. You might ask NOCO that question as well.

My Conclusion (debate welcomed) -

All that having been said, I'd go for it and install the NOCO but do charge up the battery to 14.4v before installing it, and please do let us know how it works out.

Yet another edit:
Mitsi wrote:... Yet in their manual they specify using a Lithium Ion battery charger. The charge voltage is specified at 14.6V and max charging current of 24A...
You do realize that NOCO wants to sell you their charger? Any modern regulated charger will work for you. If it doesn't have a lithium setting, then just set it to Gel (or maybe even AGM - read the charger specs) to avoid exceeding the 14.6v upper limit. Their battery 24A maximum charge current limit is pretty high and most portable chargers are lower than that, so no problem.
EVs: Two '12 Wht/Blu SE Prem., '13 TeslaMS85, three 156v CorbinSparrowsLi(NMC), 24v EcoScoot(LiFePO4)
EV Conversions: 156v '86 Ram PU, 144v '65 Saab96, 48v1kW bike
RIP(2021) ICE: Orig.Owner '67 Saab96V4, '88 IsuzuTrooper; '76 MBZ L206D RHD RV

JoeS
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Re: 12v Battery - All You Ever Wanted To Know

Mon Nov 29, 2021 10:03 am

Well, I put my money where my mouth is and just purchased that NOCO NLP30 on Amazon Cyber Monday for $140 instead of $200, as I had given one of my i-MiEV AGMs to a friend and the old FLA can't possibly keep going much longer. Will report back on this NOCO's performance after I install it.
EVs: Two '12 Wht/Blu SE Prem., '13 TeslaMS85, three 156v CorbinSparrowsLi(NMC), 24v EcoScoot(LiFePO4)
EV Conversions: 156v '86 Ram PU, 144v '65 Saab96, 48v1kW bike
RIP(2021) ICE: Orig.Owner '67 Saab96V4, '88 IsuzuTrooper; '76 MBZ L206D RHD RV

ed5000
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Location: Castro Valley, CA

Re: 12v Battery - All You Ever Wanted To Know

Mon Nov 29, 2021 10:47 am

I just bought a 12 volt, 50Ahr lithium lifepo4 battery with built-in bms for my mini-grid system in my home for general charging of misc. devices like cell phones, tablets, radio control lithium polymer batteries and some led lighting i have installed.

I've had this system since 2007 since I first bought my Harbor Freight thin film solar charging system with a 20% off coupon. Back in 2007 when my local utility charged me 8.9 cents per kwhr I was consistently saving $5 per month for every cell phone I moved over from the "big grid" to my "mini grid". When I moved my broadband router over I began saving $10 per month. I still have my "mini-grid" system even though I have roof top solar now because it works so well and has been very reliable for a long time now although I have up graded all the parts a few times along the way.

The latest change to my mini-grid is this Lifepo4 battery plus a solar charge controller rated for lithium batteries. I've only had this battery for a few weeks now but so far the battery has been amazing. I run all my loads on this battery but they never use more than the surface charge off the battery. Ie the battery's voltage at rest is 13.3 volts but by next morning it still is sitting at 13.3v. The lowest I've seen is 13.2v so far although I admit this is a brand new battery.

I'd just like to say I would give it a try. Like Joe says just watch the maximum designed charge rate of the battery while trying not to exceed that and keep an eye on low temperatures. There are actually lithium batteries out there that have built in heaters for low temp situations. I'm finding some of the price points to be about the same as lead acid so this might be a good time to give it a try.

Btw: This 50Ahr battery is only a little larger than our I-Miev aux. battery but weighs much less.
2012 ES, Cool Metalic Silver, cold weather package, no quick charge, no fog lights.
2012 ES, Black, cold weather, quick charge, and an optional net for the very back. :mrgreen:

Mitsi
Posts: 9
Joined: Tue Jan 09, 2018 5:24 am
Location: Toronto, ON.CA

Re: 12v Battery - All You Ever Wanted To Know

Mon Nov 29, 2021 2:05 pm

JoeS wrote:Well, I put my money where my mouth is and just purchased that NOCO NLP30 on Amazon Cyber Monday for $140 instead of $200, as I had given one of my i-MiEV AGMs to a friend and the old FLA can't possibly keep going much longer. Will report back on this NOCO's performance after I install it.


Awesome, we can compare notes! :D

Mitsi
Posts: 9
Joined: Tue Jan 09, 2018 5:24 am
Location: Toronto, ON.CA

Re: 12v Battery - All You Ever Wanted To Know

Mon Nov 29, 2021 2:24 pm

Thanks so much for addressing this JoeS!
After researching a bit, your thoughts very much mirror mine, but it's great to have a second opinion.
I did get some car battery size terminals with #8 screws the Noco required. They are brass or copper.
I'm thinking about getting a Noco charger to keep it float charged when idle. Also thinking about setting it up for quick removal for the cold season, but wonder if there are any hazards to regularly removing this battery. One thing I experienced today is the car with exclamation point idiot light being lit after using a Noco battery booster to get her started. Their line is "Starts dead batteries", so yes it does, but I think the idiot light is caused because her memory has lost our driving history which it needs to estimate range. The range reading fluctuates up and down between 50-90kms. I assume that idiot light will relent once we've driven far enough for her to have the data.

Sounds like you got an awesome deal on the NLP30. I paid about $300 Canadian. Wasn't thinking "Black Friday". :oops:

JoeS
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Re: 12v Battery - All You Ever Wanted To Know

Tue Nov 30, 2021 9:50 am

Mitsi wrote:...Also thinking about setting it up for quick removal for the cold season, but wonder if there are any hazards to regularly removing this battery. One thing I experienced today is the car with exclamation point idiot light being lit after using a Noco battery booster to get her started. Their line is "Starts dead batteries", so yes it does, but I think the idiot light is caused because her memory has lost our driving history which it needs to estimate range. The range reading fluctuates up and down between 50-90kms. I assume that idiot light will relent once we've driven far enough for her to have the data...
You've identified three topics -
1. "the car with exclamation point idiot light being lit after using a Noco battery booster to get her started. " Presumably this was with the FLA? Could you describe exactly what you did? Don't suppose you took any voltage readings? Which battery booster so we can see its specs?
2. "The range reading fluctuates up and down between 50-90kms." Could you elaborate the conditions? It's not unusual to have Range Remaining (RR) vary significantly, especially when climbing hills. Simply turning on the heater reduces the RR by 20%..
3. "I assume that idiot light will relent..." Have you tried to read the fault code using the OBDII and something like the iCarSoft i909?

How long (and how many miles) have you owned your i-MiEV?

Maybe someone else can discuss issues with 12v battery removal. When swapping out 12v batteries I've usually attached alligator clips to the terminals and kept the car alive with an auxiliary 12v battery.
EVs: Two '12 Wht/Blu SE Prem., '13 TeslaMS85, three 156v CorbinSparrowsLi(NMC), 24v EcoScoot(LiFePO4)
EV Conversions: 156v '86 Ram PU, 144v '65 Saab96, 48v1kW bike
RIP(2021) ICE: Orig.Owner '67 Saab96V4, '88 IsuzuTrooper; '76 MBZ L206D RHD RV

JoeS
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Re: 12v Battery - All You Ever Wanted To Know

Wed Dec 01, 2021 1:50 pm

My Experience With NOCO NLP30

The battery came in less than a day with free shipping from Amazon, and I don't even have Prime!
It is so light, even compared to my own LiFePO4, that I can't help wonder if they left out something. :o :geek:
I'll be doing some testing, such as charging/discharging the battery at various voltage and current levels, measuring its charging and discharging Ah, and in general want to get comfortable with the NOCO before installing it into the i-MiEV.

Three things right off the bat:
1. Terminal post adapters that I recommended (in an earlier posting) fit perfectly, with no drilling required. I had misread the spec sheet and the NOCO terminal thread is indeed M6x1.0. Corrected the above posting.
2. The NOCO arrived with unknown charge level, but measured 13.15vdc.
3. My Battery Minder lead-acid battery charger did not want to work with this LiFePO4 battery (too smart?), so I resorted to an older charger with manual settings. I have a number of adjustable-current power supplies which would have worked as well. Charging at 2A as I write this...

(to be continued)
EVs: Two '12 Wht/Blu SE Prem., '13 TeslaMS85, three 156v CorbinSparrowsLi(NMC), 24v EcoScoot(LiFePO4)
EV Conversions: 156v '86 Ram PU, 144v '65 Saab96, 48v1kW bike
RIP(2021) ICE: Orig.Owner '67 Saab96V4, '88 IsuzuTrooper; '76 MBZ L206D RHD RV

JoeS
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Location: Silicon Valley, California

Re: 12v Battery - All You Ever Wanted To Know

Thu Dec 02, 2021 4:35 am

Here's the link to the NOCO website for this NLP30 battery, which itself has links to the User Guide and Data Sheet.

https://no.co/nlp30

INITIAL TESTING

One thing to note about some LiFePO4 batteries is that, after charging, they settle down to some quiescent voltage below their charging voltage. This NOCO behaves like that as, after being fully charged to 14.2v it has settled down to 13.34vdc, very reminiscent of my Headway LiFePO4 cells.

CHARGING

I elected to use my West Marine 30A charger because each of its charging voltage and charging current settings can be independently programmed. For my first charging test I charged at only 2A. Initial as-received voltage was 13.15vdc, and I set its first charging voltage to 14.2v while measuring Ah delivered. It absorbed only 3.3Ah to get there before the charger cut off. Cranking up to 14.3v and finally 14.4v produced an increase of only 0.1Ah, with the charger cutting out almost immediately, indicating a fully charged battery. I'm personally not comfortable with the manufacturer's 14.6vdc recommended charging voltage and didn't go there.

DISCHARGING

I have a West Mountain Radio CBA automatic constant-current tester which allows me to set the discharge current and cutoff voltage while accumulated ampere-hours are being recorded. I set the current to 2A. NOCO does not list its low voltage cutoff protection circuit voltage limit, so I chose 3.00 volts per cell or 12.0vdc, and let it run. It had a fairly flat curve for most of its discharge, initially dropping immediately to 13.0vdc (from about 13.5v soon after charging), and only dropped rapidly at the tail end (typical for LiFePO4), recording 7.86Ah capacity. Nothing unusual.
Edit: here's the photo of the screen (sorry about the poor quality - long story):

Image

RECHARGING

I recharged using 14.2v at 2A and recorded 7.7Ah. Didn't bother charging any higher.

CONCLUSION

The battery meets its stated 7.8Ah specification, even though I didn't run it at the lead-acid battery industry standard of a (very slow) 20-hour rate as that doesn't necessarily apply to lithiums.

COMMENTS

1) There is no access to the individual cells inside the battery so I can't check to see how well the cells are balanced.
2) I was surprised that the battery had been shipped with a (7.8-3.3)/(7.8) = 58% State of Charge which is rather high when compared to shipping other lithium chemistry batteries.
3) The manufacturer specifies a charging voltage of 14.6vdc which is right at the upper voltage limit of LiFePO4. I don't know why it's so high since the application the battery is intended for is motorsports and conventional ICE voltage regulators operate between 13.5v and 14.5v (the i-MiEV dc-dc is around 14.4vdc at room ambient temperature). I'm presuming the internal cell balancing does not rely on this 14.6v maximum to be applied, as its marketing blurb touts "auto-enabled, advanced battery management system that provides maximum protection, performance, and bi-directional cell equalization for long-lasting stability" Whew!

WHAT'S NEXT

Even though I'm itching to install this battery into the i-MiEV, I'm going to play with it a bit more and next see how it performs at higher currents, although I'm chicken to test its maximum 80A maximum continuous current rating (as that would last less than 7.8/80 = 0.0975*60 = 5minutes and 51 seconds. Peak ICE starting current is spec'd at 700A.

QUESTION

Does anyone remember if we have measured what the quiescent current draw is by the i-MiEV when it's parked and either locked (with/without key fob) or unlocked? I'm just curious as I'd like to calculate how many days the i-MiEV can remain parked with this 7.8Ah battery.
EVs: Two '12 Wht/Blu SE Prem., '13 TeslaMS85, three 156v CorbinSparrowsLi(NMC), 24v EcoScoot(LiFePO4)
EV Conversions: 156v '86 Ram PU, 144v '65 Saab96, 48v1kW bike
RIP(2021) ICE: Orig.Owner '67 Saab96V4, '88 IsuzuTrooper; '76 MBZ L206D RHD RV

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