I bought a battery backup..........

[charlie b]

FWIW, almost all the batteries are made in the same factories overseas.  The differences are in the charging electronics, and these days even those are part of the battery mfg process.

Check yours fairly often, especially the LiIon or LiPo types.  The newer chemistries tend to cause swelling of the packs when left fully charged over a period of time.  They do not burst, just swell a bit.  The LiFe packs are a bit more forgiving that way, and they do not burn as readily as the other chemistries.

[Arizona Wayne]

FWIW, almost all the batteries are made in the same factories overseas.  The differences are in the charging electronics, and these days even those are part of the battery mfg process.

Check yours fairly often, especially the LiIon or LiPo types.  The newer chemistries tend to cause swelling of the packs when left fully charged over a period of time.  They do not burst, just swell a bit.  The LiFe packs are a bit more forgiving that way, and they do not burn as readily as the other chemistries.

That seems contradictory since you want them charged in case you need them. 

[Tom]

Here's a novel thought.  Read and follow the instruction manual that comes with the battery pack, no matter who makes them.

[Wayne Orwig]

That seems contradictory since you want them charged in case you need them. 

Lithium type batteries tend to deteriorate faster at 100% charge. They are quickly destroyed if under-charged or over-charged.
Most companies recommend closer to a 50% charge for long term storage.

Basically, charge it the way you need it to be used, don't expect it to be any good in 5 years.

Oh, and the hot car trunk is the worse place to keep it. What to do, what to do.

[Arizona Wayne]

With the help of much more knowledgeable users here I ended up returning my 12A overpriced Stanley unit and ordered a $34 200A smaller Walmart unit (snap suspenders).   

[kevdog3019]

With the help of much more knowledgeable users here I ended up returning my 12A overpriced Stanley unit and ordered a $34 200A smaller Walmart unit (snap suspenders).   

I hope you don't want to jump any cars with that!  It will probably jump a sb Guzzi with time but that's about it.  Good for a phone re-charge.

[Arizona Wayne]

I hope you don't want to jump any cars with that!  It will probably jump a sb Guzzi with time but that's about it.  Good for a phone re-charge.

I have a separate 1 for jumping car/truck.

[Wayne Orwig]

I hope you don't want to jump any cars with that!  It will probably jump a sb Guzzi with time but that's about it.  Good for a phone re-charge.

It just used my $31 one on my daughters car.
Good investment IMHO.

[charlie b]

There might be some misunderstanding about capacities.

The batteries will have a max cranking current, such as 200A or 400A.

They also have a capacity, which will be something like 12Ahr or 12,000mAhr.  For reference, your phone is probably around 2000mAhr (but it is also only 3.7V). 

A 12Ahr battery can still put out 200A, but can only do that for a couple minutes.

[Arizona Wayne]

There might be some misunderstanding about capacities.

The batteries will have a max cranking current, such as 200A or 400A.

They also have a capacity, which will be something like 12Ahr or 12,000mAhr.  For reference, your phone is probably around 2000mAhr (but it is also only 3.7V). 

A 12Ahr battery can still put out 200A, but can only do that for a couple minutes.

Peak output of 400A = 200A actual output in reality.  That's what I go by.

[Guzzistajohn]

I got one @ Sam's for $19.95 last night<shrug>

[Arizona Wayne]

I got one @ Sam's for $19.95 last night<shrug>

Is it a Schumacher 300CCA like I saw @ Walmart today?