[Kiwi]

Gremlin.

It draws off both packs and it will drag way more than 4 amps I promise you. The battshare only really works when there is no load or very limited load but as soon as you apply load the voltage will drop on the high pack (we are talking zillionths of a volt here) and the other pack comes in the work in parallel. If you have two 2400 Mah Fromeco packs you will have continuous access to about 5C on each pack. Thats a short circuit capacity of around 20 amps.

However if you have a 5C load on each pack for any length of time mate, you have more problems than I care to mention. Like locked, ganged servos or such.

The sports series are specifically designed for 50cc to 100cc models. Good packs with 20g battery cables gives you an assured current capacity of 6 amps continuous to the PEX. A properly setup servo system even with ganged servos should only draw 100 to 150 Mah at idle. The JR style plugs while rated at 3 amps continuous (3000 Mah) will surely tolerate a spike of as much as 7 or 8 amps. (8000 Mah) But just for a spike, not continuous.

In these sized expanders there is ample protection as they are rated at a fraction of their real capacity.