Space is now getting a bit tight as I look for a place to mount yet another battery. The Duralite 7.4v, 1450 mah LiIon pack for the smoke pump needed a home and this is where I planted it. The securing method for a number of things such as this battery and the engine ignition module are accomplished by drilling a couple holes in the ply deck and looping a wire tie through and around the item to be secured. Latex foam between it and the deck affords some cushioning to mitigate vibration damage.


New 7.4v 2150 Mah Duralites Now Installed


If you’ve been reading the blog and keeping up with the Build Log, you’ll recall a problem I had with the 7.4v, 1500 mah LiMn battery packs turning up flat dead one Sunday afternoon when I went to work on the plane. Well, I returned those packs to Duralite and exchanged them for 2 new conventional 7.4v, 2150 mah LiIon packs. The new packs charged up just fine and I’ve been using them to run the receiver and power bus pro in my efforts to setup the control surface throws. All seems well with the new ones and I am waiting to hear back from Jack Price with a report on the failure mode of the original packs. The Lithium Manganese chemistry is relatively new to the hobby and I really have no idea as to what happened to cause them to fail. Better to have it happen in the build stage than in the flight stage. These battery packs are actually a bit smaller and easier to mount.

Charge Jacks Installed for all Battery Packs


When the need arises to charge your battery packs at the field or at home, it’s always nice to have charge jacks installed on the airplane to make this task quicker and easier. This also allows you to quickly easily check pack voltage between flights. With 4 packs on board the Yak, it’s pretty much a requirement. I chose to use the Ernst charge jacks for all 4 packs. The picture above shows the installation of the one for the smoke pump battery; typical of all 4 jacks. They are very good quality and fairly easy to install. Getting the charge connector to seat fully in the jack is a bit tricky as you have to use a small screwdriver to push it into the jack far enough to get the tabs on the back to snap down behind the back of the connector, thus, locking it into place. If you get this to happen, then the connector pushes out when you plug the charge plug into the jack.