Adjusting the LVC on the RTR Revolt 30

[Tom899]

Is there any way to adjust the LVC? I believe it is set very low, about 3.00v. I know I should time my boat and bring it in but a few times I ended up stranded without much warning. A few friends with Proboat Mystics seem to have the luxury of bringing their boat in after they let it set for a minute whereas mine only leaves enough voltage for the steering servo but the motor won't budge. Again I realize I should bring it in before it gets to this point but in reality it always doesn't happen. If the included speed control is not adjustable can you please recommend an adjustable one I can replace it with? Or, maybe it's just me, my batteries, etc... Looking for guidence from more experienced than me. I don't mean to complain as I think this boat is awesome and can't think of another RTR I would rather have.
Thanks,
Tom

[Mike Caruso]

Tom,
I found the same thing just yesterday pulled my buddies packs down too low I thought 2.90. I did like Grim's instruction sheet said and run the boat a short time and check how much left in battery's. Grim 4s great battery so far most power of others I have tried and is always cooler after running. Hyperion battery's close second might even pass a blind fold test tells me you get what you pay for in battery's This is my first Electric boat and I love it. Car guy's do not understand how hard our battery's work. I am looking for a different ESC I think not sure yet. 45 mph is just fine for me with this boat I need to get back there. Then start building a faster different boat LOL.
Mike

[Tom899]

Yes, you are correct about the LVC, default is 11.63v divide by 4 = 2.9075v per cell. Is this kind of low or normal?

[Tom899]

...2.9075v per cell. Is this kind of low or normal?...
Instructions I've read say not to go below 3.0v per cell. And none of the AQ ESC's are adjustable, for anything including voltage.

If you would prefer an adjustable ESC, might I suggest a HobbyWing Seaking 90-amp unit?? Stocker is 60-amps and barely enough. I just downloaded the Revolt manual, under the motor specs section it states "Max. Surge Current: 80A/5 sec". And the stock ESC is 60-amps, hhmmm....

Seems like a 90-amp ESC (or more) would be a much safer choice than the stock 60A, I attached the HW ESC manual to this message.
FYI: default LVC = 3.2v/cell. JMHO

Thank you for suggesting this ESC. I like it and it looks like it will do what I want.
Tom

[dana]

If you end up stranded, you're going past the lvc. The lvc should cut you're power in half, which means its time to stop running and bring the boat in. Pay atttention to this. If its not cutting power in half and just stopping you probably have some other issue there.

[Doby]

Nothing wrong with the stock controller...its been proven by many to handle way above the stated ratings. ESC's tend to be rated below what they can actually handle to help protect some people.

[Mike Caruso]

Nothing wrong with the stock controller...its been proven by many to handle way above the stated ratings. ESC's tend to be rated below what they can actually handle to help protect some people.

Second that only because my ESC is always cold when I bring it in. I have to fix the temp on the ESC or just swap motor temp for one run. I do have 5.5 mm Castle connectors, but ESC to 1800Kv still are 4's.

[Mike Caruso]

Tom's original question was: is there a way to adjust the LVC on the Revolt's ESC. As we all know, the answer is no.

That was my primary reason for suggesting the Hobbywing Seaking series, the other being personal experience with 2 of them.

35-amp unit I put in my Rio when I first upgraded it to brushless, and the 60-amp unit I used with my AQ Wildcat EP.

I set the timing on the 60-amp unit to 11.25-degrees for the same reasons I suggested. That subject has been brought up somewhere on this forum previously, think it was in the UL-1 section.

If having adjustable LVC is an issue for Tom, then he will of course have to replace the stock ESC with an aftermarket unit. My replies & suggestions are based on personal experience. I still feel an upgrade is in order, but that's just my opinion. I don't want to risk starting a "pissing match", so I'll leave it at that.

Tom, good luck with your endeavors no matter which way you choose to go.

Regards,

Hey Billy,

I think you have given great info. Now when I have to up-grade I have no problem following your recommendations. You have been there done that. This is my first Electric boat so I am learning from you and anyone else who post's. So by all means don't ever stop my friend!!!!!! I hope someday to help someone reach 100 mph like I am shooting for not with a Re Volt HA. So I can help the next persons.

Mike

[Tom899]

Tom's original question was: is there a way to adjust the LVC on the Revolt's ESC. As we all know, the answer is no.

That was my primary reason for suggesting the Hobbywing Seaking series, the other being personal experience with 2 of them.

35-amp unit I put in my Rio when I first upgraded it to brushless, and the 60-amp unit I used with my AQ Wildcat EP.

I set the timing on the 60-amp unit to 11.25-degrees for the same reasons I suggested. That subject has been brought up somewhere on this forum previously, think it was in the UL-1 section.

If having adjustable LVC is an issue for Tom, then he will of course have to replace the stock ESC with an aftermarket unit. My replies & suggestions are based on personal experience. I still feel an upgrade is in order, but that's just my opinion. I don't want to risk starting a "pissing match", so I'll leave it at that.

Tom, good luck with your endeavors no matter which way you choose to go.

Regards,

Thanks Billy and everyone else- I appreciate your advice and all the ESC information I can get.
I'm a beginner with boats and Lipo's so all of you know more about this than me. The bootom line is i'm just looking for a better way of knowing when it's time to bring my boat in before I get stranded, which has happenned three times so far. My boat seems to hardly slow down and no warning before quiting. I have two sets of nano 5000mah 45c/90c with a Power Lab 6 charger controlled through my computer. I always balance charge and the batteries are in great shape. A few friends in the club have Pro Boat Mystics and if there boats should happen to quit, they let it sit for a minute or so and then they can then bring it in. Now I assumed this was because there LVC was set higher and still had the voltage to limp it in. So, again this is just my assumtion and beginners thinking so I'm certainly not dead set on needing an adjustable ESC just thought it might help? Maybe I should be looking at another solution.
Thanks,
Tom

[dana]

I dunno man, the studder bump feature always worked fine on all my aq escs. Always. I dunno what's going on with yours but, I guess go buy an aftermarket esc, then sell the factory one. Should have no problem selling it.

[Tom899]

I dunno man, the studder bump feature always worked fine on all my aq escs. Always. I dunno what's going on with yours but, I guess go buy an aftermarket esc, then sell the factory one. Should have no problem selling it.

Can you please explain how the studder bump works? I don't see anything happenning to mine, unless I don't know what to look for?

Thanks,
Tom

[Grimracer]

Dana,
Couple things...
1. I'm at AQ's website and have the Revolt manual on screen. On page 3 they have the motor & ESC specs and info on the subject of LVC.

First the motor specs = Max. Constant Current: 50A -- Max. Surge Current: 80A/5 sec. --- Now the ESC... Output Current: 60A continuous maximum -- 72A surge maximum. As you can see, in a surge situation the motor is capable of drawing more current than the ESC can deliver. The Revolt is not the only AQ boat that has that issue, they all do. The 60A ESC in the Revolt is also used in several other AQ boats, MC, UL-1 and others. The 45-amp ESC in the SV27's are also underated for the motor used them.

The 50-amp ESC that comes stock with the Wildcat EP is also underated for its motor, that was one the reasons I replaced it with a 60A Seaking unit out of the box.

The ESC in the Rio EP is notorious for frying when used with 8.4v batteries, AQ has a tech note on the Rio page but it's 200% pure BS!! as myself and countless other Rio owners have discovered. There are dozens upon dozens of posts on practically every forum on the net (not just this one) on that subject. The Hammer EP suffers the same problem because it uses the same ESC.

What that tells' me is: AQ are cheapskates more interested in profit than making a quality boat. Doesn't matter if it's a $160 entry level boat or a $350 FE.

2. AQ's LiPo ready ESC's have a feature called "stutter bump". On page 3 of the Revolt manual they discuss the subject of "stutter bump" & LVC. Here's what it says...

Notes about using LiPo batteries in your boat: The Revolt uses the AquaCraft 60amp motor controller. This controller has a built in stutter bump system that cycles the power to the motor when the battery voltage reaches 12V. This is designed to warn you of impending low battery voltage and subsequent shut down. It also has a 10.8V battery cut off safety system that shuts the power down to the motor to avoid damaging the batteries.

3. Somewhere on this forum there's great thread about boat ESC's, how to calculate what amp ESC you should use for your application and so on. In that thread various posters make statements such as: boat motors pull far more current than there car / truck counterparts, boat ESC's are often times over-rated (advertised 60A is really a 45~50A), allowing "overhead" and other really useful info. Part of the reason for allowing overhead is because of the false amp ratings. The figures I've seen are in the 20% ~ 30% range, I personally go with 30%.

Using the above Revolt specs with 30% overhead I find that I should have a ESC with a minimum of 65A continuous, which of course is 5-amps greater than the stock unit. And 104-amp surge - a whopping 32-amps more than the stock unit. That is why I suggested the 90-amp Seaking unit to Tom in my first reply.

Based on the above info, I maintain that the ONLY thing wrong with Tom's ESC is that it's cheap factory POS that needs to be replaced with a qualitiy aftermarket unit like the Seaking series.

Tom, should you decide to go with one of the Seaking units there's something I would like to point out. By default the motor timing is set at 15-degrees, AQ ESC's are set at 10-degrees. I ran a Seaking 60A unit in my Wildcat and took the timing down to 11.25-degrees because the next lowest setting is 7.50-degree's. Obviously 11.25 is a lot closer to 10 than 7.50.

Hope this extra info gets you pointed in the right direction.
Regards,

Aha yes.. I feel the love........
Grim

[dana]

Tom, there should be a noticeable studder in the motor operation when it kicks in. Surprising you havent noticed it.
Grim, i hear ya man. My escs have all worked flawlessly

[Tom899]

Tom, there should be a noticeable studder in the motor operation when it kicks in. Surprising you havent noticed it.
Grim, i hear ya man. My escs have all worked flawlessly

Maybe it is working and I don't notice it? I love the boat and hardware, everyone watching me run is impressed. I'm just trying to maximize run time and bring it in before it quits. I've been successful recently by bringing it in after about 5 minutes, which is probably a little early, but it's no fun to be stuck out on the water with no wind or current to bring it in. If you guys tell me it is what it is and an adjustable ESC will be of no help than I will just live with bringing it in early. I still don't quite understand the studder bump, maybe my boat has been too far away for me to notice it? It seems to all of a sudden slow down and stop, all within under 10 seconds. I don't mean to start any disagreements, I'm in the learning mode and looking for advice more than anything. If there's a better way or new piece of hardware that might help I don't mind hearing about it.
Thanks,
Tom

[dana]

Without seeing it run it's hard to tell man. You can buy a seaking esc for cheap money that are adjustable. 5 minutes is a good run.

[Doby]

Grim, i hear ya man. My escs have all worked flawlessly

Agreed, I guess the 6 AQ controllers I've been racing for the past 3 years must be the only good ones..aside from Dana's..

Electronics are UNDER-RATED...Period.

[Tom899]

Agreed, I guess the 6 AQ controllers I've been racing for the past 3 years must be the only good ones..aside from Dana's..

Electronics are UNDER-RATED...Period.

I think mine might be working perfectly also. Infact I'm sure there is nothing wrong with it and I never said there was, just was wondering if there is anything better on the market that might help my situation. In my case it could be me not fully understanding everything. Sorry if I opened up a can of worms, didn't mean to.
Thanks,
Tom

[Tom899]

Without seeing it run it's hard to tell man. You can buy a seaking esc for cheap money that are adjustable. 5 minutes is a good run.

Good feedback Dana, I didn't know 5 minutes was a good run, so maybe I'll just stick with 5 minutes and be done with it.
Also, I had a great run last night by stacking my batteries in the middle instead of side by side, completely got rid of any chain walking and 42.4mph. So with this in mind my next battery will be a single 4s and i'll try another company. You know, maybe the characteristics of my nano batteries are not allowing the studder bump, maybe all of a sudden they drop fast? A different company battery should prove this out.
Thanks,
Tom

[Doby]

No Problem Tom...

[dana]

When it studder bumps, don't just hold full throttle. Let off the trigger, then give it just enough juice to get it in...

[Doug Smock]

Sorry if I opened up a can of worms, didn't mean to.
Thanks,
Tom

You didn't open a can of worms Tom.
These guys have been a little cranky lately, not sure what's up with that.
Doug

[rjs62]

what about lvc alarms ? I bought 2 of these to run my lipo's in our cars which have no lvc for lipo's

so far they work excelent ! seem to start chirping around 3.6 volts per cell !

http://www.ebay.com/itm/270658077401...84.m1497.l2649

[Tom899]

When it studder bumps, don't just hold full throttle. Let off the trigger, then give it just enough juice to get it in...

Ok, I'll try that out if I see studder bump.
Thanks,
Tom

[Mike Caruso]

Ok, I'll try that out if I see studder bump.
Thanks,
Tom

Morning Tom,
My boat I only hit studder bump once and batteries were way low.
I was up at 4.20 AM us old guys don't sleep good, just often. I am running this morning and I have one more thing to try to find the lost mph. I will update when I get back home.
Mike

[Mike Caruso]

Hey Tom,
I got sick from the Sun yesterday and still weak. I will post later when feeling better. I did run 42 and 43 mph on mirror glass water with my Re Volt. I have found that I have a lot of wear in the strut. Looks like it was spinning the brass sleeve and the end large section dug into the strut. Thought I had more than needed air-gap drive dog to brass sleeve. I did polish the brass sleeve with 1500 in direction of rotation when it was new 30 runs now. On another note when I was at the Hobart race I bought raffle tickets and won a Aquacraft Top Speed 3 tunnel outboard boat very nice. Need to talk with outboard electric guys now or swap it for ?
Mike

[Tom899]

Hi Mike,
Hope you get feeling better soon!
Thanks for the updates. I'll have to keep an eye on my strut and sleeve. I upgraded my flex shaft and brass sleve in the beginning and the sleeve did not fit, too small. I ended up sanding it quite a bit untill it fit. I called Steven at OSE and he didn't know there were different size shafts, he tried one out and found the same thing. He promptly refunded and is working on a solution. The stock one is .214” and the new one is .218”. Nice deal winning the boat!
Tom

[Napalm]

I have the same issue where mine will studder then just shut down as soon as i notice the studder i immediately stop driving and i loose all power to the moto after i let out of the throttle but i still have full steering capabilities. i thought it was a bad esc so i bought another one of the same model but still same problem so im going to buy a new esc and properly program it so then hopefully i wont have these problems. just not sure on what esc to order

[Mike Caruso]

I have the same issue where mine will studder then just shut down as soon as i notice the studder i immediately stop driving and i loose all power to the moto after i let out of the throttle but i still have full steering capabilities. i thought it was a bad esc so i bought another one of the same model but still same problem so im going to buy a new esc and properly program it so then hopefully i wont have these problems. just not sure on what esc to order

You don't have to buy anything just pay attention to your running time, you are just running a little to long.
Mike

[Napalm]

thanks mike i will have to keep better track of time from now on i guess.

[Tom899]

I have the same issue where mine will studder then just shut down as soon as i notice the studder i immediately stop driving and i loose all power to the moto after i let out of the throttle but i still have full steering capabilities. i thought it was a bad esc so i bought another one of the same model but still same problem so im going to buy a new esc and properly program it so then hopefully i wont have these problems. just not sure on what esc to order

Yes, it seems timing is important. I'm going to finish the season with the stock ESC and keep it to around 5 minutes. Next spring I'll probably get the bug to upgrade some parts and an adjustable ESC is on my short list. Two friends in our club have ProBoat Mystics. This is how there ESC's work. If they happen to run too long and the boat stops they let it sit for approximately one minute and then it will run again very slow, but enough to get to shore. I'm guessing it's because the LVC is set higher and the batteries can recover slightly, but this is a guess on my part. I could be all wrong, but would like to experiment, it’s a hobby, right.