Originally Posted by configurationspace
The advice you're seeing here is from a wide range of people's experience with totally different lithium ion batteries. They're not all the same. Much of the advice above is from people with no experience with the new Li-I batteries designed for bikes (using things like the A123 technology). So pick and choose carefully!
Just for the recpord, A123 has been sold in bankrupcy to the Chinese.
Attempting to spin an electric starter under high load (H-Ds, BMW boxers, diesel engines, etc.) at cold temperatures when friction and rheological losses are high (cold oil and tight engine tolerances) with a battery that is not delivering full starting voltage places a high load on a variety of starter circuit components like the solenoid, the starter and other electrical components that rely on the correct voltage to function properly (ABS) and the reason that many diesel applications use two or more 12 volt batteries in parallel, some in series-parallel to provide 24 VDC starting voltage.
I have replaced starters on marine diesels. Those starter motors are hugh and draw lots of current. If the available battery voltage is low, you're gonna damage something.
For these reason, I'll not be using lithium batteries in my vehicles just yet.
Warning: if your starter is turning very slowly or all you're getting is the solenoid clicking, do not attempt further starts until you have restored full battery charge. Otherwise damage to your starter system may result.