Although the craft batteries for both of these systems are the same size, they differ in design.
The Typhoon H LIPO is a 4S (4 cell) Lithium ion Polymer battery. The nominal, storage charge, is 14.8 volts, or 3.7 volts per cell. The maximum charge is 16.8 volts, and in use the first low voltage warning comes at 14.3 or 14.2 (flying voltage). Flying or loaded voltage will be several tenths lower than resting, unloaded voltage. Typhoon H Batteries
H-520 craft use 4S High-Voltage LIPOs, also called LIHV (Lithium Ion High Voltage). Their nominal, storage voltage, is 15.2, and the maximum charge is 17.4 volts. Default low voltage warning, 30%, which it is recommended you not change, comes at about 14.45 volts (flying voltage). H520 Batteries
If you have both of these systems, it is possible to fly either craft with either battery. Obviously using a Typhoon H battery in the 520 will result in shorter flight times. Note that the battery chargers are different, and you cannot charge both battery types with the same Yuneec charger. Don't worry, a wrong battery will not physically fit.
An aside: both system controllers, the ST16 and the ST16s, use 1 cell Lithium batteries, and both charge with standard USB chargers. Although industry one cell Lithium batteries have been known to fail, it is rare; nevertheless, do not store these controllers in extreme hot or cold temperatures.
When any LIPO battery is fully charged, remove it from the charging device.
Note that Yuneec chargers may take 3 hours or so to charge a craft battery, and the ST16s battery will take longer if it is at a low charge. This is normal, the Yuneec chargers operate at the recommended 1C charge rate, about 5 or 6 amps. If you use an after-market charger, set it no higher than 6 amps. Yes, it is possible to charge at a higher rate, but at the expense of battery life and safety. Do not do it.
For maximum battery life and safety, charge within the same day you will fly. Always keep a watch on batteries while charging. Unless you need to fly longer, fly batteries down to 14.6 to 15 volts, then store until next time. This will also shorten the recharging time. Never leave batteries in the craft. Never leave batteries in a hot car or in freezing conditions. Always keep batteries in fireproof bags or containers when not in the craft.