Portable Jump Starter OK?

The d battery comment is intriguing. I've been looking for a compact jump starter, but I don't like any of the lithium ones that I've seen. All of them are poorly made and likely to self-destruct after a few uses (at least starting a regular gas engine).

It looks like the short circuit current on alkaline D batteries is probably only around 10A (but I haven't tested it myself). That's not enough to do much, but maybe they would charge the starter battery just enough. I'd probably want to use 9 of them for 13.5V.

Rechargeable D batteries are interesting, because they have very low internal resistance. It looks the they could theoretically provide 100A or more (based on 11mohm internal resistance)

 

Split post because the forum software is garbage. It keeps deleting what I wrote.

Even better might be NIMH AAs. Two Maha Powerex AAs in parallel would be about 17.5 mohm vs. about 18 mohm for their D cell, but the AAs are 1/3 of the cost. A length of pipe could be used as a custom high current battery holder.

 

I used a SuperCapacitor based jump starter when I had to jump my Prime about 13 times because of a bad battery (now replaced by the dealer). Works in any weather from -40 to 120 and the best part is it uses the remaining charge in the 12V (even down to 7V was the lowest I measured) to charge up the SuperCapacitor.


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