@CSH
They are Tough 1 saddle bags for horseback riding. $29. Amazingly enough they fit the LaFree perfectly (they also fit my Vado which has a pink set). Just toss them over the battery on the rack, and use double sided velcro to "strap" them to your bike frame via their sewn-in loops on the back and sides of each pocket. They have two really nice and deep insulated bottle holders that are easy to access while you are riding and hold up to a 1 liter bottle, and two outside "slip into" pockets to put stuff that you want to retrieve more often than once on your ride, rather than opening the zippered pockets all the time. The saddle pack also has adjustable straps - one on each side - that clips together on the same side, or can be crossed across the back of the battery to clip on the opposite side for any bigger item you want to carry, such as a heavy rain coat, a sleeping bag, etc.
The side bags are strong enough to carry a second battery. They aren't quite tall enough for the zipper to be closed, but I have a secondary cloth bag my battery is enclosed in, and that bag fits nice and snug in the pocket with the strap crossed over on top to keep the secondary battery securely held against the bike and in the pocket while riding.
I have five sets in various colors - pink, blue, purple, black, and red - I use the blue, black, and pink for the bikes, and the purple and red for the horses.
Here are two of the saddlebags on the bikes. The pink one on the Vado was modified slightly by folding over the part that goes across the rack and sewing that fold together so that the bags sit higher on the Vado. I did that because the Vado battery is in the downtube, and I'll be carrying the second battery in a cloth case strapped on top of the rack. It won't fit into the pockets because it is too long. The LaFree second battery sits in the saddle bag side pocket and just protrudes from the top of the pocket by a few inches.
The bottle holder can securely and easily carry a bottle up to 1 liter in size (see below for example).
I sewed two pieces of polyester webbing on the back of each pack for my clip on lights. There are tabs on the back of the bags, but they weren't quite big enough for my light clips
Profile from the front. The bags are very slim when empty, so the bike looks sleek and not like a donkey carrying a load whether it is or not
And best of all they're relatively inexpensive at $29 a set from horseloverz.com, and comes in tons of colors.
The Velcro I use is the One-Wrap Double Sided that fastens to itself. The bags don't interfere with the bike in any way, are super easy to take off, and have a waterproof coating on the inside so that things in the bags stay dry.
A very useful set of panniers that are fun, colorful, FIT like they were made for the bike, and super affordable.