Jump started my car with the help of 6 Panasonic NCR18650A this morning...

Off-topic Chatter
21

Bugsy is pretty much spot on.

I would only amend that to say instead of arbitrarily replacing a battery at a specified age, they should be tested UNDER LOAD twice a year, once before summer, and once before winter. This is more important in areas that see very hot and very cold seasons.

Given how expensive automotive batteries have gotten over the years, which have practically doubled in cost over the past 10 years, I’d be more inclined to test a battery and replace as needed (before it fails) than to just spend the cash to do it whether it was still a good battery or not.

You can if you want, but I’d rather test and know going into it ahead of time, then spend $80-$100 every 2-3 years that may or may not be warranted.

Bugsy is also correct that lead-acid batteries lose overall capacity and the ability to withstand extreme temperatures if they are ever deep-discharged. They should always be stored at 100% (12.65v). Sometimes, even a new battery that is allowed to die completely, may not recover and be usable any longer.

On that note, I should also state that battery voltage (0-100%) is not a linear progression.

100% = 12.65v
90%= 12.50v
80%= 12.45v
50%= 12.10v

I wont go further, but consider any battery at 12.00v to be basically “dead”.

It should also be noted that extreme vibration can cause internal damage to car batteries, so make sure that they are secured in their battery trays. Replace or repair your hold down clamps! A battery bouncing around inside an engine bay is going to have a short life.

Tsetse, I have to ask why your battery would routinely drop down to 12.45v (80)? If your alternator is working correctly, and you haven’t installed some crazy high wattage, high amperage sound system or a bazillion off-road lights, or similar, then there should be no reason why a healthy battery, maintained by a healthy alternator ever drops below 90-95 state of charge.

If it is, then the battery is getting weak and I’d watch it like a hawk, because it will suddenly fail on you and leave you or the wife stranded at some point in the near future.

Also keep in mind that even if the battery seems to still be doing its job of starting the car, and you arent seeing any vehicle charging issues, at 80% nominal voltage, your battery is causing your alternator to have to output more voltage to make up the difference between 80 and 100% state of charge. 0.30v doesnt sound like a lot, but to the alternator, that can be a 30-40% increase in output that it may or may not be able to sustain for very long.

22

Can you clarify your OP: Did you use two holders (with each holder with 3x18650 in series) and then you put each holder in parallel with the original (bad) car battery? And once it started, you just unhooked the 2 holders from the whole configuration.

Also, during the period when the car had started, and when you unhooked the holders, was the alternator pushing current through the original battery AND all of the 18650s?

23

And yes, it should be common automotive knowledge. Some of this, like the state of charge info can be found in many car owners manuals. Which no one reads.

It’s just like how no one seems to care to replace their brake fluid every 2 years or 24,000 miles… yet then they wonder why the seals in the master cylinder or brake caliper failed and leaked black dirty brake fluid everywhere.

And don’t get me started on the failure to change transmission fluid… people, if the filter and fluid was not meant to be replaced, the owners manual will state so, and they would have made the filter a permanent part of the transmission, not replaceable behind a tranny pan with removable bolts!

Most owners can’t even be bothered to put good wipers on their cars, or replace a burnt out headlight… but I’m getting off topic.

Let’s just say that automotive electronics and charging system can be about as “user-aware” intensive as charging and discharging unprotected Lithium Ion cells.

Oh, and that reminds me, NEVER EVER EVER FOR ANY REASON EVER try to charge up a car battery that is either A. Frozen, or B. low on “water”. It will very likely EXPLODE. And not the gentle “vent with flame” but full on BOOM! blow your hearing out explode. If the battery case has swelled and expanded… don’t do it. Replace the battery with new and send the old one to be recycled.

24

You are right, the two holders were connected in parallel then the leads connected to the car battery connectors/leads, then when the car started, I just disconnected the leads to the battery as fast as I could.
also true that when the car was started, it was briefly still connected to the 18650.

Ok, now for disclaimer: I don’t recommend anyone to perform what I did. Do it at your own risks.
Maybe JasonJ or Bugsy care to elaborate on the related risks…

25

I was thinking that if I use the car for frequent short trips only, the battery will possibly not be able to charge back to 100%? no?

26

Short trips of less than 7 miles may not sufficiently maintain charge on a healthy battery, correct. If the battery is weak or started off with a lower charge, then the problem is compounded.

I would expect that you would need multiple short trips in a period of time to really see an issue here. My mother-in-law drives a 2000 Chevy Tahoe 5.3l exactly 1.3 miles to work and back 5 days a week. It has a healthy, but 3-4 year old battery and no charging problems that are known.

We haven’t seen any issues arise from this short trip routine since they bought the vehicle 15 years ago. It has had 3 batteries in its life, including the original.

That’s not to say all cars will operate this way. You may indeed see slight discharge on the battery after your short trips. You’d have to check battery voltage and compare it to my percent-voltage numbers posted above.

27

That procedure is done all the time. The vehicle does not care if power is coming through AC mains and a rectifier or 18650's etc etc. It wants 12 to 15 volts to start. Common safeguards should be used though such as NEVER LOOK OR STARE AT A BATTERY WHEN STARTING A CAR even when not jump starting. It is much easier said than done though.

28

I just tested the new battery: it is 13.10v with the car off… does that mean that it is over charged? or that my meter is just bad :stuck_out_tongue:

29

No, it means its charged. These battery’s are charged using 14.xx volt, so when they are charged the voltage is above 14 V but will sag to around 13.5 V ( maybe even lower, not sure) after some time.
So that battery is full.

30

It’s called surface charge, or surface voltage. It will drop to nominal voltage over time. Usually if you give it a few hours, it’ll come back down to 12.65 or thereabouts.

It’s normal and indicative of a good battery. A bad battery will not retain its voltage and drop down significantly, and quickly.

31

I got one of these things a while back
and it helped sort out the still-useful batteries from the ones immediately ready to recycle.
(I keep AGM type cells longer as they don’t spill; a weak one I wouldn’t trust on the car (on a camping trip in remote areas where starting has to work)
may still be somewhat useful as a backup-to-my-backups earthquake power source. I put a small solar charger on it and set it out in the sun and its voltage stays ok, though the amp number is significantly low.

“Solar” is just a brand name, there’s nothing “solar” about it.
https://www.gemplers.com/docs/FAQ_Solar_Battery.pdf

32

Impressive. Kudos to you sir!

33

Two people I know just had car batteries die. Here in California, they seem to last about four years for a four year battery, and five for a five. Go figure. I would take the old battery in for the core charge, and be done with it. Nice ingenuity with the 18650s. I wouldn’t have tried it.

34

There are small jump-packs sold for just this purpose. My brother bought one from Amazon. He’s jumped both of his cars and his motorcycle with it. Has a small flashlight built in and some nice removable cables and solid clamps. I’ll see if I can find a link to it.

35

When buying new car battery, do not be fooled with “no maintenance” marketing. If possible buy battery with good old screw caps and refill with demi water couple times a year. Thing is those “no maintenance” batteries still loose fluid and plates get dry, resulting in dead battery in most cases just as a warranty runs out ! Hot climate only accelerates this…
My last car battery (cheapest store brand but made by FIAM) lasted over nine years with this treatment !

Also, car batteries are no longer made to be best possible, but to bring the most profit…

From my personal experience, korean batteries on kia and hyundai vehicles are still very good. For example “rocket” battery is still in a good shape on KIA K2500 truck from year 2004 !!!

In the old days it was quite normal for car battery to last around 10 years. In our former country Yugoslavia, best batteries were made by “Trepca”, lead mine and factory that made U-boat batteries during WW2 J) and they were renowned for very long service life…

36

I used to be on RC hobbies forums, and remember some guy reporting he started his truck with a 4S 4500mAh 30C rated lipo pack, using 18AWG banana plug leads! pretty amazing it worked with a couple low drain 18650s. I had plans for making a DIY emergency starter with 8x25Rs, integrated flashlight and phone charger, but it was too expensive to get the housing done with a 3D printer.

37

Amazon has dozens of li-ion jump packs. I have had very good results with Rockford , DBPower, and Floureon packs. I work in heavy construction and all of them have been able to jumpstart diesel machinery. You only get 1 or 2 chances with a diesel, but they will start gasoline engines several times off of one charge. Make sure to get one with high Mah, my latest DBPower has 18,000 and was only about $75. Hard to believe, I know, but they work!

38

I am aware of these powerbank jumpstarters, and one is on its way to me on the slow boat from china, and i will hopefully receive it in a couple of months… I’ve seen some reviews and they all seemed positive, but remains to be seen if you can still store them in the car when you need them the most or they just die too in the heat or worse burn down my car.
Actually i’ve seen some advise having a idiot proof cable,not a bad idea actually.
But still if i could get 10 years on my battery would be better. But now that am thinking, back in the days i have never heard my father complain about his car battery… Maybe they were really just better

39

What I want to see is a complete replacement of the lead acid battery. Why can’t you run a power pack in place of one of those antiques?

40

It’s not the new batteries that are bad compared to old. My 32 year old van still gets 5+ years from a mid-grade battery and I could stretch it a couple more. It’s 42A alternator wouldn’t power a new car at all. The change is that new cars work the battery harder, charge it at a higher rate so that it can keep up, that underhood temperatures are higher now, and that they tend to size the batteries smaller for weight and build-cost savings. A combination of many things. And my ancient machine is happy to do everything including starting at 11V as long as there’s enough amperage left. No cheap batteries in your car ever, but you probably won’t get your cost returned from a ‘super-duper’ battery either though it may be worth the peace of mind it gives to you. If your car battery is run down to the point where you need to jump-start more than twice for any reason (lights left on or non-use) and there’s nothing wrong with the car, it’s time for a new battery. It should take 4-5 over-discharges but it’s not worth pressing your luck, and after two it’s on the way out already.

Jump start packs are handy. Many have a cigarette lighter socket making them useful for using car accessories remotely and bench work. But if you need them for jump-starts there’s something wrong with your car or you and they can’t fix that. If you have a little-used vehicle you need to get a float-charger for it. Small machines that only get seasonal or occasional use absolutely need this. Wet-cell batteries sulphate and die when left sitting around unused and alone. Cars of today place huge demands on the battery and it has to be in top notch condition or things go sour quickly.

Like the OP sometimes you get caught out and have to improvise. A power tool battery will get you started similarly if you leave it hooked up a few minutes before starting. Anything will work as long as it has enough power to overcome the dead battery’s internal resistance and bring it up to enough voltage. If you get an ‘almost start’ in really cold weather, sometimes bringing the battery into a warm house for an hour will do the trick, Buy when the battery is really and truly a goner, nothing is going to work except a new battery.

Phil