Speed - Electric For all your electric boating needs.

Upgrading Hobbyking Relentless V2

Reply
Old 05-15-2017, 12:28 PM
  #1
HeineDenmark
Thread Starter
 
Join Date: May 2017
Posts: 1
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default Upgrading Hobbyking Relentless V2

Hi.
Im pretty new at rc boats and the brushless setup. So im hoping for a little help. A month ago i bought the Relentless V2 boat from Hobby King. I guess it was an okay good boat and all. But i wanted more speed. The stock version runs 2x2cell lipos, 60amp esc and a 1900kv outrummer motor.
I wrote the guys at HK asking for advice to upgrade the boat to 2x3cell lipos. Thay suggested to buy the 90amp esc and let everything else run stock. Well that went pretty wrong and the boat blew up in the middle of the pond in under a minute. I got in contact with HK again a straigt away they shipped me a new boat and esc. (Good Service)

So here's my question again.. I have now bought a 120amp Marine esc from HK instead of the 90amp esc. Will that work???

i heard the 90amp esc can't handle 6cells even thugh it says so on the specs. So thats why i bought the bigger one.
sorry for my bad english :-)

HeineDenmark
HeineDenmark is offline  
Reply With Quote
Old 09-14-2017, 05:12 AM
  #2
cablecar
 
Join Date: Sep 2017
Posts: 16
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

It depends on your Motor KV, Higher KV normally draw higher Amp and require Bigger ESC. You can refer to Most Brushless Motor Technical Spec. and see the Max. Amp correspond to KV. If your motor now is 1900kV should be handle 4S means 2x2cell in series got 15.6V (Max 16.8V in Full Charged). and Running in 1900x16.8 Max 31920rpm.
If you try 2x3cell in series Max. got 25.2V and running in 47880rpm. If your motor power is small (I don't know your motor power KW), it will draw out High Amp and Overheat. so you better refer to your Motor Technical Spec. and see can it handle or not, then you can choose a Right ESC to fit for it.
Now if you try 120A ESC and 6 cell with it and notice the temperature. If too hot, try smaller prop. Or Try 5 cell. Using 2S and 3S in series (With Same Capacity and C).
cablecar is offline  
Reply With Quote
Old 09-15-2017, 03:51 AM
  #3
Got RPM
 
Join Date: Nov 2006
Location: Texas TX
Posts: 645
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Cool

The boat comes with a 60 amp ESC, and upgrading to a 90 amp ESC makes sense when upgrading to 6S, but the OP should have started with a smaller propeller. The increased rpm/amp draw from changing to 6S overwhelmed the small drive system when he tried running the same 4S prop. I don't know the specs on the stock prop, but a 2-bladed prop of the same or slightly smaller diameter should be safer.

Going to a 120 amp ESC may not help at all. Now the tiny motor becomes the fuse in the system and will likely give up next. The small outrunner is poorly cooled and has limited mass to contain the extra heat generated on 6S. Propping down is the best solution.

Most newer boaters do not realize that running their boat at part throttle extensively will overheat their ESC and often causes it to blow. The more powerful the setup the easier it is to do severe damage - like upgrading to 6S with no other changes. The stock boat on 4S has enough safety margin to prevent this, but adding 50% more voltage can and will cause problems. The safest way to run any upgraded RTR boat is to use full throttle 90% of the time. Why run a fast boat slowly?


.
Got RPM is offline  
Reply With Quote
Reply


Thread Tools
Search this Thread
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -8. The time now is 12:35 AM.