Capacity would be expected to be less by as much as 50% on cycle one, and not less than 75% for cycle 2, and then something in the 90% range thereafter, so Yes, you have a defective battery or charger in my opinion.
Contact HTB immediately and ask for help troubleshooting, and a refund or exchange if you find a problem. Hopefully you just have a charger that shuts off early, but some stinker cells in the pack is likely.
4 amp charge time for that pack should be in the neighborhood of 6 hours for a fully discharged pack. So either its only got 1/4 of normal capacity or less, or it's only charging to 1/4 of the normal capacity. Step one, is check the output voltage of the charger with a voltmeter. I got a WE kit once with a charger that put out 18v. Needless to say it did not fully charge a 36v sla pack. Then check the voltage of the battery, both on the regular output, and on the wires before the bms. You could just have a stinker bms.
In the future, post a question like this in the battery section. Here it may not get seen by that many battery guru's.
THE LIPO RULES. NEVER ABOVE 4.3V NEVER BELOW 2.7V DON'T PUNCTURE
Ideal charging /discharging range for Lipo, 3.65v minimum 4.1v maximum
See battery technology section, FAQ thread at the top of the page for lipo noob info.