We were going to buy the BH5 but went with the 356QBQ, so this may or may not apply to you.. . We love out trailer, but I'd at least upgrade the battery capacity, since its a pretty big trailer for such a small battery. We went with a full solar system, wasn't that expensive and we can do without power forever. Never had an issue of not having enough voltage, unless we are wanting to run the A/C. We also do the sine wave inverter, so we can still use all the appliances, etc.
Test your water heater, make sure it works on both gas and electric, also test your refrigerator for the same things. Both of those was not working when we got ours, and we didn't realize it till we camped the first time. Also the wheel well covers are attached with terrible screws, and there is no support int he middle, so the flop around. Screws worked themselves out on the first drive.
Be careful of your brakes as well, ours were apparently locked when they towed it to the dealer, so they were completely gone. Then when we had them opened up we found out the bearings were open as well. Apparently its a known problem. Couldn't get Camping World to warranty it even though we just bought it from them that week, without a month or two delay, so we just had someone else replace them.
We couldn't even get the same brand, since they were "MOVING" as well, and we couldn't get forrest river to answer the phone, so we dropped $2k on that repair the first week we bought the thing.
Also the shower shut off keeps the water running the entire time, its a good idea to replace that with a better shut off. There is also much better shower heads as well, which we replaced on ours.
Also do not run more then one pop out at a time. If you ever blow a fuse for them they are inside the wall in the cargo bay. Stupid place to put them.
I am sure I am missing a few things