Rumple90,
I also have an Ionics system in my van & had same trouble like you.
I bought 3 backpacks for myself & my lads and must say they have been brilliant for what i needed them to do.
Only faults are i find the batterys just do not last long enough for the length of time i neeed them, but if your only going to use them for a couple of hours - then will be invaluable.
I have just bought an Ionics 35ltr trolley , execellent = Should have bought a trolley a long time ago, especially for moving from A to B.