My Duralast Gold Jump Starter does not take a charge when I plug it in to the wall socket. While the charger is connected to it, it will show the green light. But when I remove the charger, after having had it charge for several hours, by pressing the test button I get the red light. Is there a battery inside that I need to replace?

There is a battery inside which may need to be replaced. To check, run the compressor (it runs off
the battery) - if the compressor dies quickly, then the battery has failed to charge and would
need to be replaced. You may want to check your Warranty Management software (or
shoebox) to see if your Starter/Air Compressor is still under warranty - if so, replace it.
Duralast products are carried exclusively by AutoZone, Inc.
The Duralast web site: www.duralastparts.com is useless - it only shows automotive parts,
and I cannot find the product at www.autozone.com, so it seems that AutoZone fails to support this
product with replacement batteries or other replacement parts (or even an online Users manual).

Here is one it's listed under "Schumacher-Duralast"

https://manualzz.com/doc/51884984/schumacher-duralast-dl-800-jump-starter-and-dc-power-sour...

I have a Duralast Gold BP DLG 1200PS and it did not come with an instruction manual. How can I get one?

Yes' there is a battery inside. now as far as replacing it - you will want to talk to your local battery supply shop and see if they can make one up or order one for you.

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