The SVD has built-in protection. Using protected batteries will cause damage to your SVD chip and cause it to shut down or worse. NEVER USE PROTECTED BATTERIES IN REGULATED MODS.
IMR type batteries are recommended for APV's, they are a safer chemistry without a protection circuit. Protected batteries in a protected device often leads to trouble. VV/VW devices place a high drain on the batteries, protected batteries will shut down when they noticed such a drain.
The SVD is a protected device. When the other person asked what kind of battery, the type of battery should have been included in the answer. That is, is the battery an IMR, is it a protected battery. If you are unsure, post a link to the batteries you have, if possible.
Edit: Just noticed this was started way back in May, oh well.