Due to the fact that typical smartphone durability and battery life of is not not always suited to outdoor conditions, I would like to ask you about some simple mobile phone with dual sim. Second-hand items are acceptableRequirements:dual-simhigh quality and durable constructionlong battery lifegood call sound qualityprice range up to $100
Mobile phone used only for calls & SMS
mobile phone
The Crosscall Shark V2 seems to fit almost all your requirements. Almost, because with the current exchange rate (Euros to USD) it costs 101$.It:floats (water resistant)is IP68 certificatedThere are two other phones you may want to look into. The Caterpillar B25 and the newer B30. Here's a comparison of the two.The only real difference is the battery life. Based on the above linked comparison, the B25 has a bigger battery capacity (1300 mAh vs. 1000 mAh), but the stand-by time is almost 100 hours lower, although the talk time is 3.5 hours higher. Well, on the CAT homepage they seem to have the same talk time. But the B25 has much more detailed specs there than the B30.Only the (factory) price is a bit high. It's about 157.90$ (140 Euros), but, as you stated in your question, since second-hand items are acceptable you'll find both phones much cheaper online (50-100$), for example on eBay.Both CAT phones are:IP67 certificatedwater resistant up to 1 meter (3.3 feet) for 30 minutesDrop-to-concrete resistant from up to 1.8m (5.9 feet)I can't make a statement about the call sound quality because I have never held one of those phone in my hand. If you can, check the phones out in a store and compare the sound quality.