Trunk mounted battery is history. BACK to the front ! NEW tech, too. Lithium battery

[Kern Dog]

Sometime around 2013, I moved the battery to the trunk.



I had a blue top Optima that weighed 44 lbs. I had read that moving the battery to the trunk helped with traction and weight transfer though I never cared much for drag racing. I did like the extra room in the engine bay.
Over the years, I've gone through a few batteries. I just attributed that to the fact that the car sits idle for most of the time. It was wired correctly and well grounded. I ran the positive cable to a FORD starter relay, then other other side of the relay had the 1/0 positive cable running right to the starter. It was only live when cranking since I had a trigger wire going to the stock starter relay on the firewall. I had 2 ground cables to the negative side of the battery and the engine itself had 3 ground cables to it.
Lately I've noticed the most recent battery won't stay charged up. Even when disconnected, it would discharge at a rate of .035 volts a day which adds up to .45 volts in 2 weeks. The battery is on it's way out.
Why do these batteries fail so often?
I don't blame the trunk location for the issue but it is inconvenient to have to open the trunk to test voltage, then charge it. I started thinking about changing to a different type of battery.



I had two different Optimas, the AGM shown above and most recently, a standard lead/acid battery from maybe 2 1/2-3 years ago.



Awhile back I started looking at the weight of the car and thinking of ways to lighten up where I could. When I replaced parts, I looked for stuff that might weigh less than what I am replacing. I was pushing 4000 lbs with the car a couple years ago.



I added modern A/C and removed the original HVAC box. The front brakes were upgraded with a Dr Diff 13" kit that shed 24 lbs compared to the Cordoba 12" discs. Tubular front sway bar shed 8, the spacesaver spare tire shed 21. Borgeson steering box was 12 lbs lighter. Now that I'm looking at a battery replacement, I'm looking at these:



Mopar Action magazine did an article on these Lithium batteries. A friend of mine has one in a '68 Plymouth. His car cranks over FAST and the battery only weighs 7 lbs!
I recently removed all the trunk mounted battery stuff. Battery box and hardware, holddown, solenoid, all cables and wires. It added up to almost 18 lbs. The engine bay location adds up to 4 lbs including battery tray and holddown and battery cables. The trunk relocation costs you 14 lbs of extra weight. If I do go with the Lithium battery, that is a 33 lb reduction from my 40 1/2 lb battery that I have now. I could be close to 3900 lbs with the lightweight battery mounted up front!

[Nacho-RT74]

Eating less biscuits will help on less weight while driving too

        

[Kern Dog]

Eating less biscuits will help on less weight while driving too

        

Ha, no kidding.
Since I retired, I've put on 20 lbs. I used to be a Carpenter, carrying lumber, climbing up stairs, framing roofs, hauling plywood...
Not much of that now but at least I'm not stuck in traffic commuting anymore.
I know that chasing a lighter overall curb weight won't make a huge difference in anything. I'm a decent driver but I'm not so good that I could tell a difference when the car is 40 lbs lighter.
The trunk battery was sort of cool when I did it because it was different and the engine bay looked less cluttered. Having the battery up front is more convenient though.

[Kern Dog]

The return is complete. The trunk mount is out, it it's place is the bag of tools and ignition parts for road trips:



One of the weight saving moves was this space saver spare from a 2016 Charger. The late model bolt pattern is not exactly the same but will work for short distances.



I made a shorter holddown stud. The stock one was about 10 inches long.



Back up front.



This battery is a side terminal design so I used matching cable ends. They are temporary, I'll explain in a moment.




The headlight relays used to sit on a flat steel plate that was bolted to the stock battery recess in the fender apron. I had to relocate them within the range of movement the wires had. They look decent right here.



Now, regarding THIS battery....
It has something weird going on with it. It loses charge on it's own even when it is not connected to anything. Sometimes when I am charging it with a small charging unit, the unit shuts off before the battery reaches 12.6 volts. For example....I connected the charger last night when the battery was at, say....12.3v. This morning it was maybe 12.46 and the charging unit had the GREEN light which indicates that it is fully charged Or at the least, it thinks that it has. I disconnected the power from it, waited 20 seconds and then reattached the plug to the wall socket and it started charging again. A half hour later it was up to 12.67.
Great!
I started it up and ran the engine a few minutes, then went off to do some things. Later I went to start it and it cranked like it had no spark. It spun 25-30 seconds, tops. The starter struggled to spin the engine and in that short time, it quickly got slower...enough to not even spin the engine over fast enough to start.
I'd bumped a wire loose from the ballast resistor. That was the reason for no spark. I checked the battery and it was ay 12.10v. Yeah, it somehow lost half a volt in around 30 seconds of cranking. I hooked up the charger again and within a half hour, it went from 12.10 to 12.56. If this turd charges this fast, it also discharges even faster. I am going to go ahead and order a Lithium battery tomorrow.

[Kern Dog]

Same old story with this NAPA battery.
A couple days ago it was at 12.23 but that was still enough to start the engine. Today it was 12.15 at it just made a rapid series of clicks so I put the charger on it. It is like rearranging deck chairs on the Titanic though since I'm going to replace it with THIS:



This dude weighs just 7 lbs! A friend of mine had his 68 Plymouth here while I did a Vintage Air installation and he had one. It is amazing how light and powerful they are. Rick Ehrenberg of Mopar Action magazine wrote about them in a tech article about ways to shave weight from your car. I tested his battery in my car and was shocked at how fast it spun the starter compared to my battery. The Mopar Action magazine showed that the Lithium battery spun their 383 over at 330 rpms vs 250 with their lead-acid battery.
This one was $450. Not cheap but hey...I have no kids, I don't smoke, drink or use drugs so I'm not living in squalor here.
These are shipped below their full rate of charge.



You have to charge them fully before installing them. They require a specific charger to avoid OVERcharging which puts them at high risk of early failure. I ordered one but it is 2 weeks out.
When Dwayne's Plymouth was here, I used a 12V drop light while working underhood. It ran his battery down so I used my standard charger on it to bring it back up. I was careful since I was told about the risk of overcharging. I was in the shop the whole time it was charging and I tested the voltage periodically. It reached full charge within a couple of hours. That was in February 2024 and the battery is still okay.

[70 sublime]

If you are worried about over charging the battery with a stand by charger why do you think your car charging system will be any easier on it and not over charge it ?

[Kern Dog]

I know, it does not make sense to me.
They warn to use their charging unit because these batteries don't give a "signal" to the charging unit that the battery has reached full charge yet an alternator is fine?
In the Mopar Action magazine, Rick used a trickle charger, a regular one. That guy is a stickler for doing it right, he is no "Roadkill" type guy.
It is advised to use a voltage regulator that is adjustable so charging can be limited to 13.8 to 14.2 volts. I already have one of those in place and it does work.

[b5blue]

Made in China? 

[Nacho-RT74]

I was to post some pics taken from an Instagram reel about China products in USA... But probably will turn out on a political thread more than been taken as a joke... so... preffer to keep safe from that. LOL.

IF YOU PROMISE NOT TO TAKE IT AS A POLITICAL THREAD but as a joke (like intended)... I could post them

[Kern Dog]

I didn't look at where this was made, I looked at who recommended it. I don't know where it came from.
Political or not, not everything made in China is junk, not everything made there is great. Take a look at your "restored" car and tell me that it doesn't have some Chinese made parts in it.
The crankshafts in most stroker kits are from China. Voltage regulators, fuel sending units, fuel pumps, bearings,  window cranks, then list goes on.

[Kern Dog]

I went ahead and charged the battery using this unit:



I kept checking it every half hour or so. Within two hours, it went from 11.93 to this:



I didn't install it yet. I need to order the post terminals. I thought that they would have been in the box with the battery but they were not.

[b5blue]

Wow you read into my question more than meant! China don't mean bad. 

[Kern Dog]

Pardon me for expecting a less than supportive comment from you...

[b5blue]

My sidewinder heads are from there! (So are the computers we use.) 

[Kern Dog]

It is off topic but I'll join in.
Sure, they are capable of making good products. Now I don't know but I suspect.... that they can make stuff as high of quality as any other country BUT I also think that a possible reason that much of the stuff from there is low quality is a complicated answer: Maybe they are just building stuff to a low standard because they were given a LOW price point to build it. If an American importer only wants to pay the Chinese builder $15 each to build an air compressor, China will make a $15 dollar unit within that budget. Sure, when it is on the shelf for sale HERE it has a list price of $149 with a one year warranty and you may get a year out of it. Taking it further, If an American importer were willing to pay $80 per unit instead of $15, the Chinese might be able to build a compressor that lasts for 10+ years which would raise the retail price to $399. CHEAP minded customers will buy the $149 model 3 times in 8 years, the other type of buyer gets just ONE that lasts longer.
Now that was just my guess, it may be different but to me, that seems possible.

[Kern Dog]

Boom, back up front:



It sat about 1 3/4" taller than the group 85 I had before. The other battery was a side terminal which meant no posts on the top.



Things all fit well. I had to change to the traditional post type terminals and reroute the positive cable but it came out well.



I put it in at 12.68 volts. It cranked over the dead cold 495 with 20w50 oil faster than usual. I let it warm up for a few minutes and restarted it. Dang...the starter spun faster than ever. I checked the voltage and it was already at 12.94. I thought that these ran between 12.6 and 13.2 but I was wrong...



Holy crap, 13.6 volts? No wonder it spins the engine over so fast!
I was borderline giddy each time I cranked it over from how fast it is now.

S C O R E !!

[timmycharger]

Nice and clean  I may look into one of those if my Optima battery ever decides to quit. The only issue I have now is slow cranking when the car is hot but I am not sure if that is due to the long 0 gauge wires going to the starter from the trunk or if I have too much timing.   

[Kern Dog]

I was surprised to learn how only being down a few tenths of a volt makes such a difference in battery "strength.



Just 3 tenths takes a battery from 100% down to 70 % ? I was under the incorrect belief that battery voltage was linear, 6 volt reading was at 50%.
This lithium battery runs at a higher voltage than a standard lead-acid unit. That alone helps the starter spin the engine over quicker. It really sounds like a late model car spinning over.
I do have a car here that I went the other way with....72 Duster with a old fashioned Mopar starter. That one sounds like the Mopars I grew up with!