Max safe input voltage for Turnigy chargers

I have a couple of Turnigy chargers (Accucell 6 & Reaktor). The manuals state the max input voltage is 18V. I have spare Dell laptop power supplies which indicate 19.5V, so they may be slightly higher, at least open circuit. Has anyone used higher voltage with these chargers, or do you have insight as to whether this would be safe? If no one knows, I'll take the chance and report back.

Also, does anyone know if the Dell plug is a standard size, and if so, where is a good place to buy jacks to mate with it? It looks like a common barrel plug, but larger. I could hack it off, but it's nice to have spare laptop chargers too.

I have some 24V Meanwells I plan to hook up in series for bulk charging 12s, but plan to use the Turnigys occasionally for balancing. Also, I could leave one at work, where there are more Dell laptop supplies.

Thank you.

If you put too high a voltage to a Reaktor it will come up with an error message.

Thanks Kinninviekid. Sounds like a little over might not work, but probably won't break it. I'll hook it up to my lab supply and figure out if it gives the error message around 19.5V.

I use a 19.5 v Toshiba laptop power supply with a Accucell sometimes. No problems, and the Tosh" plug fits the charger.
Have a rummage through the local Opshop of Computer junk piles.

Thanks Hillhater, that sounds perfect. I was rummaging through my junk and realized I've got about a dozen Dell supplies so I'll just reterminate one of them. Also noticed that the Reaktor will only work at less than one third power if powered through the jack, so I need to use the cable input anyway. I've been out of town, and haven't had a chance to check the max working voltage with my lab supply. Will do it later this week.

I hooked the Reaktor to the lab supply. 18.0V works fine. 18.1V gives the error message. I didn't test the Accucell since I didn't have a suitable plug handy, but based on Hillhater's post above, ironically the 50W Accucell will take higher voltage, but the 250W Reaktor will not. Will see if I can turn down the Dell, otherwise will wire it to a PC supply.