Lithium battery question

[peter2407]

I asked this question on another thread that was eulogising about an Anti gravity personal powerpack, but its obviouslty been overlooked, so as I am still curious, I thought I would ask the question again, which is: how can an 18000 Milliamp (18 Amps, yes?) deliver 300 - 600 Amps of cranking power? My assumption is that is an 18 Amp Hour pack that could delivery that cranking for a minute or two only. Is that correct?

 

[CreakyDecks]

Ahh, I should have read that this was a commercial product before commenting!

 

[peter2407]

Thats what these guys are claiming can be done: http://www.antigravitybatteries-uk.co.uk/microstart-jump-starter.html

 

[pvb]

Yes, it's quite feasible. Lithium ion batteries are popular as start batteries in small aircraft, due to their low weight. Obviously it's not going to provide hundreds of amps for very long though.

 

[peter2407]

Thanks Pete so my assumption that they have effectively just missed out the letter "H" is correct?

 

[pvb]

Thanks Pete so my assumption that they have effectively just missed out the letter "H" is correct?

Even battery retailers don't often understand Ah!

 

[sailinglegend420]

An engine needs only 1-2 Ah to start each time so an 18Ah battery is going to be fine as long as it is recharged straight away. I've had a small 25Ah RedFlash AGM lying on its side under the floor for ten years starting a 56HP Yanmar with never any problems.

These Lithiums are a lot smaller and lighter and a lot more expensive, and need an expensive charger!!!!

If using LiFePO4 batteries on a boat you should also consider the fire record of lithiums. Whilst these are not the type that caught fire on the Boeing Dreamliner, ANY Lithium battery caught in a boat fire is almost impossible to put out. A major UK equipment manufacturer supplying marine and service vehicles have advised their clients not to fit Lithium batteries. Apparently there are lots of new technologies being developed that will soon make the Wet Lead Acid battery look like a dinosaur.

 

[Plevier]

Apparently there are lots of new technologies being developed that will soon make the Wet Lead Acid battery look like a dinosaur.

As people were saying when I started in the battery industry in 1978!
This time it might be different though....