Author Topic: Battery Charger or Jump-Starter  (Read 25799 times)

Offline Carl

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Re: Battery Charger or Jump-Starter
« Reply #60 on: March 28, 2015, 07:48:31 PM »
Today I bought a new group 31 battery locally for $39.99 plus tax, which is the second one I've bought at this price. They still had a quarter of a pallet left I think, and will probably get more. These batteries have cosmetic defects, but no functional defects. You might do some looking in your area and see what you can come up with. I use mine as a portable jumper and as a battery for my Onan generator or Lincoln welder.

I have seen the standard jump boxes with SLA batteries work, and I've seen them not work. Any of them will have a finite lifespan just like any other battery. If I were going to buy one, I'd buy a high quality Li-ion type that fits in the glove box. They will hold a charge much better than lead acid and can have much higher safe discharge rates.

There isn't much substitute for a good charger either. I have a schumacher charger maintainer that seems to do everything I need it to do. I wish I could find a 120v charger that mimicked an alternator's charge rate/curve.

It is not recommended to go above C8 or 1/8 the rated AMP HOURS of the battery (typically 125 Amp Hours for Group 31) or about 15 AMPS maximum charge for a brief time...so a big charger would be a waste of money and likely let you damage your batteries as most group 31 will begin to outgas (and boil out electrolyte) at above 6 AMPS.

You already have a great charger ,a faster (higher AMP) charger is really only useful to fast charge and jump vehicles.

Just my opinion after many years of battery use and abuse..

http://www.solar-electric.com/deep-cycle-battery-faq.html#Battery Charging

Offline Paruria

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Re: Battery Charger or Jump-Starter
« Reply #61 on: September 13, 2018, 02:17:53 AM »
Sorry for bumping...just my thoughts...
Ok here's the problem with jump packs:

When you have a dead battery and put a jump pack on it, what you're doing is putting another battery in parallel. Two batteries in parallel equalize eventually, and one dead battery in a parallel setup makes the other sag. So what you get, is one dead battery, one good small battery, added up to make one big crappy battery.

The real solution is to carry a battery in a spill proof, insulted, vented box. Remove your car's battery and install your spare if it dies - avoid charging a battery more than 40% drained with the alternator, which is not built to charge substantial amounts. Invest in a solar battery maintainer, but beware it will take months to charge a battery significantly depending on size, it's more of a maintainer.

Pocket size jump packs are just 18650's wired in series - cheap ones are made with cheap quality cells, so you mine as well make your own with protected high amp rate samsungs - but at that point, you mineaswell just buy a spare car battery. 3 18650's = 12.6 v fully charged, 20 amp limit. On a cold day, you need more like 200 amps, plus extra for hesitant startups.

Pocket power x? It's too small. How many 18650's are in there, what type of cells? Yeah, probably POS china cells that can't hold a charge. I really doubt it started 10 busses in a row, I'd like to see video proof. Maybe started 10 busses in a row and the busses low battery did most of the work.. The website is in typical sales scam format, too.
My only problem with it is was that I go skiing somewhere where it can drop to -40F with the wind chill. The car will sit in the parking lot for a few days and I dread not being able to start in case my Blackvue drains the battery. All the chargers I looked at had a warning that they shouldn't be kept inside the vehicle in freezing weather.

A portable one made with lithium batteries would be small enough to carry in my luggage and have enough cold cranking amps to start most passenger cars and SUVs (depends on the model, some are better).

I purchased this one, made by Anker: [EDIT] -Started my 6 cylinder, 3.0L car without any issues twice and then it stopped working completely, wouldn't even turn on.

Then I purchased this one made by Schumacher [EDIT] Works perfectly and has everything I was looking for and more.
Made from lithium iron phosphate. Longer life, safer cells and more charge cycles than lead acid
-400A, 270CCA sufficient for any 4 or 6 cylinder car
Benefits over the Clore Jump n Carry: Smaller size, keeps the charge when sitting idle for longer, LED to tell you the voltage of your car's battery when you attach the clamps, automatic overload protection so it turns off if you don't remove the clamps after starting the car, spark-free
Cons: battery isn't replaceable like the clore unit


[EDIT: delted spam links, banned spammer]
« Last Edit: September 13, 2018, 05:19:26 PM by Mr. Bill »

Offline Carl

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Re: Battery Charger or Jump-Starter
« Reply #62 on: September 13, 2018, 05:32:06 AM »
  Yea,a typical start the auto cycle requires less than 1 Amp hour so a small pack can 'share' enough power with a good BIG battery to provide the burst required for starting....this assumes the auto's engine and battery are in good condition just somehow weakened .I have NEVER had true success with the 'jump pack' batteries and these new 'pocket pack' batteries are just pushed too hard to survive ,though ,if used exactly as designed....will work....until you destroy them. I relegate the jump pack as more of a portable power supply than a savior and do use them in such a manor. I am glad these  older thoughts float to the surface from time to time as often I ,and others,can benefit for a review of the wisdom of the past.

The Jumper you indicated looks like a good choice for the best portable jump pack for the new generation

Offline Bubafat

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Re: Battery Charger or Jump-Starter
« Reply #63 on: September 13, 2018, 10:12:52 AM »
Do a bit more research on batteries in parallel and the impact in amp draw and you'll find it's additive.  Meaning a "dead" battery + a jump start battery can draw the amps of the jump start battery, not the average of the two. 

The Li-ion jump packs are not necessarily designed to jump the car, they dump energy into the dead battery and then it's the dead battery that primarily jumps the car.  This is OK if you just over-drained the battery, but if there's a bad cell in the battery it will not work.  For this reason I'm not a fan of the pocket Li-Ion jumpers but a big fan of the lead acid jumpers. 

Offline Greekman

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Re: Battery Charger or Jump-Starter
« Reply #64 on: September 15, 2018, 03:52:57 AM »
Paruria
A protected 18650 battery cannot started a car.  I doubt the built in circuit can allow more than 20amps.
 The build will have to be done with a separate protection board that can handle the hundreds of the cars cranking amps.

Offline Carl

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Re: Battery Charger or Jump-Starter
« Reply #65 on: September 15, 2018, 06:47:27 AM »
  If the weak battery can't accumulate some bit of energy from the jump pack then you just aren't going to have success.