12 Volt Lead Acid Battery Replacement

The original sealed battery in the Leaf should last many years, perhaps the life of the car.. there are no engine starting duties and it should be much cooler under the hood of a Leaf.. heat is the big killer of lead acid batteries. There will never be a payback replacing that battery, unlike chrome plating the wheels lets say.

As an aircraft mechanic, what bolts are you talking about?

Skywagon said:

The lightest aftermarket wheels in a similar size are in the 11 lb range; most are around 13-14 lbs. Plus you cannot factor wheel weight. Your 140 lb loss estimate is not correct.

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Ya, I blew that simple math!

I disagree about factoring in wheel weight. Whatever weight is attached to the vehicle must be propelled up a hill. If it doesn't matter, as you say, then a simple test is to fill the wheels with calcium and then measure the performance. I predict a profound change for the worse in every measure.

My top speed up a local hill near my house was noticeably slower (82mph) than level (95 mph). Hopefully, that makes sense. Whether I add four 300 pound lead wheels or 1200 pounds of lead on the roof, both will have a measurable decrease in max speed up that hill.

TonyWilliams said:

Skywagon said:

The lightest aftermarket wheels in a similar size are in the 11 lb range; most are around 13-14 lbs. Plus you cannot factor wheel weight as static/dampened weight as it is un-dampened and rotational mass (inertial) as well. Your 140 lb loss estimate is not correct.

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Ya, I blew that simple math!

I disagree about factoring in wheel weight. Whatever weight is attached to the vehicle must be propelled up a hill. If it doesn't matter, as you say, then a simple test is to fill the wheels with calcium and then measure the performance. I predict a profound change for the worse in every measure.

My top speed up a local hill near my house was noticeably slower (82mph) than level (95 mph). Hopefully, that makes sense. Whether I add four 300 pound lead wheels or 1200 pounds of lead on the roof, both will have a measurable decrease in max speed up that hill.

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If you are going to quote me then you do not edit my statement before rebutting it. I added back in my original statement (in RED) that you neglected to include in your reply. With that missing piece your reply would agree with my original post/statement except that in the fact that wheel weight is more critical than sprung mass (added to the roof, interior, etc.).

TangoKilo said:

As an aircraft mechanic, what bolts are you talking about?

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The ones with holes ;-) Not the holes for safety wire on standard AN/MS hardware!

Usually pins with cocentric holes. Honda race motorcycles go to great lengths to lighten bolts, making concave reliefs on the heads. Of course, there are titanium bolts.

We're getting far off course of a lead acid battery replacement, and as a mechanic, I'm sure you can tell us that turbojet powered aircraft haven't used lead acid batteries in decades. Really bad NiCads in the bad old days.

Skywagon said:

If you are going to quote me then you do not edit my statement before rebutting it. I added back in my original statement (in RED) that you neglected to include in your reply.

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Working from the iPhone here. Also, I almost always edit the quotes I reply to, and will continue to do in the future, like I did in this post.

I personally hate re-reading an entire post in somebody's quote. If somebody wants to get the statement verbatim, I believe that's as easy as scrolling up.

I do "have your request" on the quotes. Expect me to ignore it every time ;-)

Hugs and kisses always,

Tony

TonyWilliams said:

I do "have your request" on the quotes. Expect me to ignore it every time ;-)

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I don't think he objects trimming of quotes (I sure don't) - just what appeared to be selective trimming which changed the meaning/context of his original statement.

Any aircraft bolt with a hole in it will cost $$$... Lead acid batteries are still very popular in most small to medium sized aircraft...

TonyWilliams said:

I almost always edit the quotes I reply to, and will continue to do in the future...

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I completely bought into your meaning changing edit and was confused until Skywagon put things straight. Cutting out half a sentence in the middle without ellipsis, and changing the meaning 180 degrees is NOT cool and NOT friendly. No matter how many smileys and hugs you put on your reply. If you can't bring yourself to take enough care to do it right, don't quote at all.

davewill said:

Cutting out half a sentence in the middle without ellipsis, and changing the meaning 180 degrees is NOT cool and NOT friendly. No matter how many smileys and hugs you put on your reply. If you can't bring yourself to take enough care to do it right, don't quote at all.

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Holy smokes guys !!! Don't know what to tell you. I did not INTENTIONALLY change his meaning, and anybody can STILL READ THE ORIGINAL. I do know that the iPhone tried to resize the font, no doubt from my fat fingers, and likely is the culprit. But, now somebody will claim I'm "covering up" and some other silliness.

Mea culpa on this one, of course. Heck, I didn't even get the weight of the wheels right.

I will continue to quote, and if it doesn't quite work out as good as the past 10,000 quotes I've done on the internet in the past 22 years, I'm not going to worry about it much.

I've got your request, too !!!

TangoKilo said:

Any aircraft bolt with a hole in it will cost $$$... Lead acid batteries are still very popular in most small to medium sized aircraft...

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All aircraft bolts cost money. Anything associated with a plane does. And you know that air cooled, lead burning engines are popular in light planes, too. Mostly because that's what's been certified many, many decades previously, and the gigantic cost to change technology for such a small aviation market, plus the certification costs, make virtually anything in light planes to be dinosaur technology. Avionics in general, and experimental light aircraft, appear to be the leading exception.

Yes, I had lead / acids in every airplane I've owned. The Barons took two of them. Replaced lots of batteries. Somebody claimed further up that heat reduced the life of batteries, and there's probably truth to that, but the Baron placed the batteries in the nose baggage compartment... unheated, and no heat from either engine. Naturally, I had one of those batteries fail on the ramp in San Diego and had to pay a ridiculous amount of money to have it jump started. The vibration is crazy in this light planes, and everything suffers.

But, the expensive non-lead/acids fail too. I've done more than one "huffer" or "bottle" start when an APU wouldn't start.

Guys with light planes are changing to lithiums now (I've seen a few) mostly for the huge weight savings and no maintenance. Longer life is just a huge plus. I don't know who might have an STC for those batteries, or if that's strictly for experimental / sport planes.

Herm said:

The original sealed battery in the Leaf should last many years, perhaps the life of the car.. there are no engine starting duties and it should be much cooler under the hood of a Leaf.. heat is the big killer of lead acid batteries. There will never be a payback replacing that battery, unlike chrome plating the wheels lets say.

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So untrue. The 12 volt probably sees a constant float charge which will cause it to die in about three years time. This is the case with any hybrid out there which does not use the battery to start the engine. In fact in EV history the 12 volt battery has been problematic since as it goes on it's way out the DC/DC works harder to keep it charged as it's charge efficiency goes down. On the S-10E it was notorious for draining the traction pack to try and keep the 12 volt topped off so owners typically would just replace it every year to avoid the problem as the battery went out.

Trust me, keep an eye on your 12 volt and load test it occasionally to see how it's going. If it starts to get weak replace it before you have to get a jump start, which will be very embarrassing if you have to jump start your EV.

So here's a dumb question. If Nissan makes its own Lithium battery pack for the motor, why don't they just build a 12V Lithium battery themselves for the Leaf instead of having to use a 12V lead-acid technology? If the answer is because a 12V lead-acid is cheaper than a 12V Lithium, but they deem it sufficient for the operation of the Leaf, why shouldn't we use the same rationale they use to replace it with a 12V lead-acid when the time comes? Why pay more for a 12V Lithium if Nissan sees it as unnecessary in the first place?

Another dumb question: Why can't Nissan tap on the main battery pack to power the 12V accessories? I'm sure if they really wanted to, they could have tapped that source with some kind of voltage step down to 12V. After all, they build circuitry to charge the 12V with the main pack. So I'm sure they can build the circuitry to deliver 12V from the main pack if necessary. It seems so ridiculous to have 2 battery sources for the car.

Volusiano said:

Why can't Nissan tap on the main battery pack to power the 12V accessories?

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There is an inverter to go from 400 volts to 12 volts. The reason for having the lead-acid battery is so that the car can be powered off and the traction battery be disconnected from the "under-the-hood" components. Helps keep things safe!

Volusiano said:

Another dumb question: Why can't Nissan tap on the main battery pack to power the 12V accessories? I'm sure if they really wanted to, they could have tapped that source with some kind of voltage step down to 12V. After all, they build circuitry to charge the 12V with the main pack. So I'm sure they can build the circuitry to deliver 12V from the main pack if necessary. It seems so ridiculous to have 2 battery sources for the car.

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Because the DC-DC voltage converter would have to be always on waiting for some usage and all the while draining the main battery. The 12v battery can just sit and wait for months at at a time.

smkettner said:

Volusiano said:

Another dumb question: Why can't Nissan tap on the main battery pack to power the 12V accessories? I'm sure if they really wanted to, they could have tapped that source with some kind of voltage step down to 12V. After all, they build circuitry to charge the 12V with the main pack. So I'm sure they can build the circuitry to deliver 12V from the main pack if necessary. It seems so ridiculous to have 2 battery sources for the car.

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Because the DC-DC voltage converter would have to be always on waiting for some usage and all the while draining the main battery. The 12v battery can just sit and wait for months at at a time.

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I agree with smkettner's statements. I also theorize that another reason for the 12V battery is to be able to operate the charging system. This would allow the car to be charged when the traction battery is drained.

TonyWilliams said:

It doesn't appear to be "worth it" to you. Some of us, myself included, don't want to have 1850's technology lead and acid in their 21st century car.

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I hate to be a nit picker but isn't the EV technically 19th century technology? Obviously the Leaf has 21st century tech but EVs have been around for a looooong time.

That being said anyone have pics of their Li battery replacement cause I am interested.

tzzhc4 said:

I hate to be a nit picker but isn't the EV technically 19th century technology? Obviously the Leaf has 21st century tech but EVs have been around for a looooong time.

That being said anyone have pics of their Li battery replacement cause I am interested.

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I hereby accept your nit, and raise you a little knowledge from our friends at Nissan:

TonyWilliams said:

I hereby accept your nit, and raise you a little knowledge from our friends at Nissan:

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It's kind of funny that if you accidentally open a door before you disconnect the 12V battery, you have to check again that the EVSE is not suddenly connected