Cheap lightweight battery suggestions

holy F, you guys just converted me from our PC680, that Zippy is sick! I'm going to use that in the Merkur next to shave off another 12 lbs...

Sorry, got the number of cells wrong. You need a 4S battery to start and run a car.

http://www.hobbyking.com/hobbyking/store/__9933__ZIPPY_Flightmax_5800mAh_4S1P_30C_.html

How does one wire in one of those R/C batterys? Any special considerations or is it really just plug and play?

DaveEstey wrote: How does one wire in one of those R/C batterys? Any special considerations or is it really just plug and play?

You had better get a bigger battery for the 7.

For those who don't know:
The S in 4s1p stands for number of cells in series (volt total).

The P stands for number of cells in parallel (amp total).

If they are truly using authentic a123 cells they are good for about 3.2volts and 125amps.

You add volts for cells in series and you add amps for cells in parallel.

So a 4s1p would be good for 12.8 volts and 125 amps, a 4s2p 12.8 volts and 250 amps, etc...

I'll stick with my AGM powersports batteries or if I win the lottery, some Prolite batteries.

DaveEstey wrote: How does one wire in one of those R/C batterys? Any special considerations or is it really just plug and play?

also curious

Plug and play. Some come with connectors. You can use those, or ground lugs like I do

Zomby Woof wrote: Plug and play. Some come with connectors. You can use those, or ground lugs like I do

Use those to attach the battery wiring to the existing 4gauge wiring in the car?

So why do my lead acid batteries cost $80+ dollars and weigh 1k lbs again?? These tiny Li-PO cost less, weigh less, and have similar CCAs. Why is Porsche one of the only car companies using these and charging a ton for them (I may have answered the second part when I consider who I'm talking about).

In reply to MrJoshua:

I have an optima red top for the 7 that I like just fine. I don't want to worry about cranking power at the hill and I'm willing to sacrifice weight for utter reliability in that case.

I was thinking for the Miata at autocross.

am I reading that right... 560ish grams? i.e. 1.25 pounds??

will 125 amps start a 4-banger?

chaparral wrote: Sorry, got the number of cells wrong. You need a 4S battery to start and run a car. http://www.hobbyking.com/hobbyking/store/__9933__ZIPPY_Flightmax_5800mAh_4S1P_30C_.html

also... has anyone actually run one of these in their race car??

very tempted to try this in the Rabbit.

Wow, this is some great info! I don't think I'll be putting the R/C or moto batteries in the car, but the lawn tractor battery might work! Keep the suggestions coming!

The lithium ion batteries are way better than a mower battery.

These Lithium batteries can sometimes flame up and the resultant fire will burn your car and your house. The model airplane guys will not charge them without being right there to watch them. Do not try using these things in your car! http://www.youtube.com/watch?v=C5_-eBbDE0s

Hmmm...I definitely don't need a fire.

In reply to olpro:

The lithium ion have that tendency yes, but the Lithium iron phosphate batteries like the a123 batteries in this thread are much less prone to burning. They are probably less prone than the lead acid they are replacing.

My intuition says that electrons are electrons so my car won't care, but are there any additional potential issues running one of these 123 battery packs on a thourghly modern car? One with big ole' computers running things and a dozen airbags or so?

They catch fire when not charged properly. The packs are sensitive to being overheated.

mazdeuce wrote: My intuition says that electrons are electrons so my car won't care, but are there any additional potential issues running one of these 123 battery packs on a thourghly modern car? One with big ole' computers running things and a dozen airbags or so?

No.

DaveEstey wrote: They catch fire when not charged properly. The packs are sensitive to being overheated.

I'm aware that one needs to use an appropriate charger to keep the explosions at bay, but does the charging system in your run of the mill car fall into the appropriate, or inappropriate category? I wouldn't mind watching with an eagle eye when it's plugged in at home, but I strongly dislike the idea of burning to the ground at a stoplight.

I don't think the newer ones catch fire, but the charging system in your car is fine. Been using them for a few years in my car and bikes.

Muchas gracias.
I think I know what I want Santa to throw on the sleigh for me.

So, in theory, one of these (http://www.hobbyking.com/hobbyking/store/__14074__ZIPPY_Flightmax_8400mAh_4S2P_30C_LiFePo4_Pack.html), weighing in at a whopping 2 pounds and change, would be able to start a small-block V8??? That just sounds nuts...

92CelicaHalfTrac wrote: Use those to attach the battery wiring to the existing 4gauge wiring in the car?

Yup.

No problems with the thin 14 g wire coming out of the battery getting hot. The positive is taped, but it's wired the same as the negative. FYI, they have internal protection (chip) that prevents them from catching fire like the original ones did and shorting the battery will kill it.

OK... I guess you really CAN use these to start a SBC... that's impressive... http://www.youtube.com/watch?v=izGq6jb948M