Changing the 48V dolphin battery case on the Radrover. Step by step.

walawn

Active Member
Ok, so as some of you who follow this forum may know, the first week I had my new Radrover I was an idiot. I went out for a multi-hour afternoon ride and didn't lock my battery onto the frame with the key. Of course it wasn't until the last few miles that I hit a bump that sent it flying off the bike at 20 mph only to hit the paved trail, bounce, and skid it's way to a stop. The battery looked like I put it into a giant food processor. Needless to say I was distraught at what just transpired and a little worried that I did some irrevocable damage to me $500 battery. I slid it back into the holder and the bike did get me home under full throttle. Please see my post on here for what I did to repair it that night (sanding down the damage and painting it with plastidip). Being the perfectionist I am, I wanted a new case. After waiting a week for the factory in China to ship it I had it in my hands (shipping cost more than the case!). Now it just so happens that I had just finished charging my battery when the new case arrived so I had no choice but to do the swap over with a fully charged (read here: 54.6 V) battery. There will always be some energy left in your battery, but it would have been safer to do the swap with a discharged battery. Now I am a certified motorcycle repair technician (15 years experience), but don't practice anymore so electrics are nothing new to me. I would advise you to wear gloves, eye protection, and remove the fuse. This post is only for informational purposes and I will not be responsible for any injury or property damage from following this guide. If you are in doubt, then don't do it!

Step by Step:

1. Remove the fuse. (this only protects the output side of the battery, charging side will be live (54.6 V)!
2. Remove the 6 screws holding the case together (5 will be long and 1 will be short.)
3. Slowly pull apart the halves of the case. Be careful of the handle/spring assembly at the top. Remember how it goes together.
4. You will need to cut the 4 power switch wires (1 red, 1 black, 2 green) going from the battery to the silver/blue power button. Note: You will need to mark one of the green wires with a marker and remember it's position (I marked the green wire closest to black).
5. You will need to cut the 2 wires going to the charging port or unsolder them. Use caution! This connection is live. Note: Remember their orientation so you can reattach them correctly.
6. I soldered some extra wire onto the charging input (6-8 inches) just because I wanted more room to work. Insulate and isolate all connections. The positive and negative are VERY close together so BE CAREFUL (maybe a mm to spare).
7. I then soldered the extra wire to the charging wires coming from the battery. Make strong connections and use heat shrink.
8. I removed the LED battery gauge display from the old case which saved me some time soldering.
9. You can just unplug the white USB connector and plug it into the new one. Also unscrew the fuse holder.
10. Place the main battery in the new case. Screw down the LED board. Plug in the USB connector.
11. Lightly place the output into the new case with the notch facing up. Do not tighten nut yet. Screw down the fuse holder.
12. Place heat shrink on the 4 power wires. Solder the black power wire first. Then the green you marked. Then the other green. Lastly do the red. Check your connections and heat the shrink to finish the job.
13. Very carefully pack all your wiring in the front and place the two halves of the case together. You want to do slowly so you don't damage anything. The extra wire I installed made this a tight fit. Check that you have power (press button and then press gauge).
14. Once you have the halves together grab your handle/spring assembly. Lightly pull the halves apart and place the handle/rod in between with tension on the spring.Once installed, wiggle the halves back together.
15. Reinstall all bolts being careful to place the short one in its place. Tighten the nut on the output at the bottom. Check your voltage at the output with the button on. You should get a reading 45-55 V. You are done!

Picture explanations:

Old and New: New case in front (pristine condition w/ keys inside it) and old case in back (with scratches and a peeling plastidip finish)
New with Holder: The new case on its side and the holder it came with. I will save it for a future project.
New Case: Once I got the new case open. This is the view that greeted me.
Cutting Old: I had to really work to get the old case apart, cutting where the seam is. As long as you don't paint your case, you can skip this step.
BMS Old: Some of you wanted to see the view inside of our OEM batteries. Here it is.
Inside Old: The padding and packaging of the cells likely saved it from damage during the fall.
Cut Power Wires: I tried to not cut any wires, but eventually had to. Here are the power wires going to the button.
Cut Charging Wires: I just wiggled them on the input until metal fatigue broke them off. Don't let them touch!
Protect Yourself: I put some heat shrink on one wire temporarily. I measured over 54 V with a multimeter once off.
Power Switch Old: Here was my attempt to muscle out the power switch, which was glued down by the factory, with a hot knife. Fail.
Old Halves: Finally got the old case off. Here are the two halves with hardware.
Gauge and USB: Here is the LED battery level gauge and USB port after removing them from the old case. I used the new USB since it was already bolted down. Simply unplug and replug.
Pack in But Not Done: Here is the battery resting in one of the new case halves with the charging wires soldered. Notice the extra wire (red/black) which let me solder without going crazy.
Orientate Input Correctly: Here I lightly placed the output plug with the notch facing up.
Finished Power Soldering: Here are my 4 power button wires soldered and heat shrunk.
Charging Leads Installed: Here I soldered extra wire onto the charging barrel plug connector. Very close tolerance. Easy to short.
Charging Leads Finished: Here is the finished job of connecting the extra wire I installed to the battery.
Finished Product: Here is the old battery in the new case!
It Even Works!: Power button lights up.
And It's Full!: Battery gauge works. Shows full. Checked voltage at output +/-. Voltage was 54+ volts.
 

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Jolly

Member
Was there any damage to any of the cells when you open it up after the battery went flying at 20mph or just cosmetic to the outer shell.
 

walawn

Active Member
@Jolly I didn't check any of the cells individually. The internal packaging was done so well I didn't want to change it. The battery is padded so I am assuming all is well. Time will tell if there is an issue.
 

Jolly

Member
@Jolly I didn't check any of the cells individually. The internal packaging was done so well I didn't want to change it. The battery is padded so I am assuming all is well. Time will tell if there is an issue.
Well I hope all is well with the battery and no issues with the cells. Ever thought about doing a shark park instead of the dolphin case for more low profile look.
 

walawn

Active Member
@Jolly I hope so too! I have thought about switching over to the 52V 13.5 Ah shark pack, but I would hate to render the stock dolphin pack obsolete. I suppose I could mount the shark pack on the bottom of the frame in the water bottle mounts and just swap the plugs from the shark to the dolphin when it runs out of juice. It would scream ebike even more with two batteries on the frame.
 

opimax

Well-Known Member
Very nice write up, like the 2 battery set up idea, your bike looks electric to me already and you dont have to leave it mounted when you dont need it, my 2 cents
 

walawn

Active Member
@opimax Thanks for liking it. I tried to be thorough. Agreed on it looking like an ebike. It's hard to make a prebuilt look stealthy. The motor hides itself pretty well within the footprint of the cassette and is hard to notice and hopefully the bag mod I did will mask the battery pretty well. Although, people that hate ebikes spot it from a mile away and shout their insults! I would just need two more batteries to balance the load in my side bags since I doubt it would fit in the rear rack bag.
 

The Bionic Biker

New Member
walawn, This is an impressive thread. Great job. Did you happen to note which BMS this battery uses? If anything ever fails on this battery, it would be the most likely culprit.
 

walawn

Active Member
@The Bionic Biker I did not. It was pretty well shrouded. I didn't want to remove any of the wrap covering the cells and BMS. One could possibly replace it for a more robust one if it fails. It seems like RPB spent the money where it counts on an ebike though: the battery, controller, and motor.
 

Lost

Active Member
Just found this thread. Seeing as I may have a great set of guts to put in one, where do I order a case from?
 

Lost

Active Member
Just spent the evening doing this. Definitely not the project for those who do not know electronics, you are absolutely playing with a loaded gun. I only had to solder the charge port, everything else came unplugged and made for an easier swap out of cases. Even the charge port unplugs so you do not have to solder it "live". My two pics, the source end of the battery and drain end. Mine appears slightly different, the BMS is mounted more to on the top of the battery pack. The replacement case had everything but the USB power supply, but no problem, I transferred
rebuild1.jpg
rebuild2.jpg
rebuild1.jpg
rebuild2.jpg
everything over.
 

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mrgold35

Well-Known Member
Hey Lost,

I have a Radrover battery that fails to charge; but, it discharges normally. The battery thinks it is fully charged and doesn't take any juice from the wall charger (the second wall charger light stays green). Even the battery indicator light on the side of the battery pack shows full bars all the time. I can only see the battery charge level when I turn on the RR LCD screen. The external fuse on the battery pack is not blown.

The battery was replaced under warranty by RR and I now have a 7 lb paper weight in my garage. Is there any internal fuse, circuit board problem, or wiring that you saw with your battery cover exchange that might explain the problem? It would be nice to fix the battery for a spare.
 

Thomas Jaszewski

Well-Known Member
Hey Lost,

I have a Radrover battery that fails to charge; but, it discharges normally. The battery thinks it is fully charged and doesn't take any juice from the wall charger (the second wall charger light stays green). Even the battery indicator light on the side of the battery pack shows full bars. I can only see the battery charge level when I turn on the RR LCD screen. The external fuse on the battery pack is not blown.

The battery was replaced under warranty by RR and I now have a 7 lb paper weight in my garage. Is there any internal fuse, circuit board problem, or wiring that you saw with your battery cover exchange that might explain the problem? It would be nice to fix the battery for a spare.
Use your multimeter to determine the voltage of the battery. That is the best way to see if it's the battery.