Heavy tank
The Char 2C was one of the largest tanks ever produced. At the start of World War II, France and the Soviet Union were the only countries to have inventories of heavy tanks, such as the Char B1, T-35, and KV-1. The Matilda II was designed under the British infantry tank concept which is similar to the heavy tank having thick armor and weighing more than their other tanks. It’s usually separate because they have less firepower with their cruiser tanks (comparable to mediums) at the time having the same main armament but more machine guns. Later war examples were the German Tiger I and II, as well as the Soviet IS series. Note that "heavy" versus "medium" is more a question of tactical roles than weight; the Panther, for example, was a "medium" tank that outweighed most Allied "heavy" tanks.
Battle of France
The Battle of Hannut (12–13 May) was the largest tank battle yet fought, with about 1,500 armoured fighting vehicles involved. The French knocked out about 160 German tanks for a loss of 91 Hotchkiss H35 and 30 Somua S35 tanks. The Germans were left in control of the battlefield after the French made a planned withdrawal and were able to repair many of their knocked-out tanks. The net German loss amounted to 20 tanks of the 3rd "Panzer" Division and 29 of the 4th "Panzer" Division. Prioux had achieved a tactical and operational success for the French by fulfilling his objective of delaying the panzer divisions until the First Army had time to arrive and dig in. The German attack had engaged the First Army to the north of Sedan, which was the most important objective that Hoepner had to achieve but had failed to forestall the French advance to the Dyle or to destroy the First Army. On 14 May, having been held up at Hannut, Hoepner attacked again, against orders, in the Battle of Gembloux. This was the only occasion when German tanks frontally attacked a fortified position during the campaign. The 1st Moroccan Infantry Division repulsed the attack and another 42 tanks of the 4th "Panzer" Division were knocked out, 26 being written off; this second French defensive success was nullified by events further south at Sedan.