Seeking Replacement for Siemens ME45: Criteria Include High Volume and Good Battery Life

My wife has been using Siemens ME45 for many years. It's been 16 years and it started to break down.
At the operator's logo shows an exclamation point and loses coverage. It's time for a change.
I wouldn't write a post because I'm not stupid enough not to be able to find a phone
The problem is only that I don't know what is "loud". I mean the volume of the ringtones, the volume on the handset and the volume of the alarm clock.
Siemens ME45, when calling, can be heard three floors below. It really is!
I have never seen such a loud phone. Just a revelation. The same with the alarm clock and speaker in the handset. In a street bang, there is no chance that you will not hear the interlocutor. We have already tried many other phones and not one passed the exam and they were:

Siemens - C35, M35, S35, SL45
Nokia - 3210, 3310, 3410, 5110, 6150, 6210, 6310, 8210, 8310, 6510
Alcatel - OT301, OT501, OT511 (the latter has good ringtones but quietly on the handset)
Panasonic - GD30, GD50
Philips - Ozeo, he was great but he began to lose range
Ericsson - T10, T18, T20, T28, T39m

From newer phones we checked:
Nokia - N95, N73, N70, 500, Lumia 520
Huawei - G620, G630-U20, Honor 7
Sony - Xperia X10 mini, X8 Pro

I started thinking about something typical for seniors.
All these weird MyPhoney and MacComy, something like:



Is that worth the interest?
They really are very loud as they write in the specifications and the battery works a week or two?

In the current ME45 I had a battery from Nokia, i.e. the cell itself. I disassembled a Siemens battery that was already finished, I desoldered the cell and soldered a new BLB5 cell from Nokia to the same chip, cutting off its chip because only that fit. The operation passed the exam, the Siemens charger recognized correctly and properly charged. The battery lasted from 7 to 10 days and over 2 years. I expect the same effects from another phone.

I'll tell you right away. I don't care what it is. Range up to PLN 400.
New, used, old, young - no matter.
Will you advise something?

Nice proposition but it is tiny but. Color display. I wish he wasn't there.
Reason? Man very often looks at the phone to check ot by hour
She also often looks to check if someone has called, if any text message has arrived, and whether we have even a line when wandering in the woods and mountains
The color screen turns black just after turning off the backlight. Nothing can be seen on it. You need to unlock the keyboard to look at the aforementioned hour.
I know it's stupid but unfortunately practical because when the phone is just in a stationary charger somewhere on the shelf you do not even need to touch it. Another more serious matter is that on many colorful screens in the sun you cannot see anything if they have poor backlight. The old type display works great here.
Colorful, however, in the summer in the bright sun it causes that often can not read anything from it. I wonder if from the electronics side it would be difficult to replace e.g. a Nokia 6510/8310 speaker and buzzer and somehow amplify it to make it louder. Are cases of such tuning known on the electrode?

I bought this Maxcom at a market sale (PLN 79.90). He is not so stupid. The battery charged on Friday evening is full today. The phone is very loud. The ringtones are ok, the display is ok, the menu is a bit complicated but you get used to it. It is important that the earphone is quite loud and even louder than in Siemens.