Hello, Boaters!

I have used "Venom" 6-pack 7.2 V 3300 mAh Ni-Mh batteries for my electric boats.

I have used these batteries only about 15 times, charging with MRC Super Brain 989.

But now all of these batteries reject to be fully charged. They are charged only upto around 1500 mAh, so that they are useless for my boats now.

I have the same problem on some Ni-Mh batteries for my electric airplane, too. I have used them only about 10 times, but the same thing happens.

I think I properly charged with a good charger that is a MRC Super Brain 989, excercising them once in a while. As you know, this charger does not overcharge.

Q#1. What is the reason of this problem? What is the solution of this problem?
Q#2. Am I the only one who experience this problem?
Q#3. If the quality of the batteries is the problem, what batteries are "reliable"? I have to buy
new batteries, because the venom batteries are no longer useable.

Your answers will be greatly appreciated. Thank you very much!

are you running them completely dead ? If not the charger will only put back what is needed .... Also after you run them dead , try charging them at like 1amp or less to re-balance the packs ... sometimes that helps .

A#1. NiMh cells must be carefully looked after and maintained. Sometimes it is just the nature of the cells. Soulution would be to properly balance the cells with a C/10 charge every five cycles or so.

A#2. No, I've been down that road as well. I've replaced many SubC sized cells due to dead cells with in a pack.

A#3. NiMh is the problem, LiPo is the solution. Look in to Flight Power cells. You will get a lot more than just 10-15 cycles out of these. And most definitely convert your airplane packs over to LiPo. I have been using LiPo for a long time now for the planes. I don't know why NiMh would ever be used for them now days. Way too heavy!!

I have a stickied thread on the top of our forum that explains LiPo in some detail.

Ryan

Thank you guys for your advices!

I tried what djr01974, but it didn't work out.

Ryan, you said, "I've replaced many SubC sized cells due to dead cells with in a pack."

Then, how to figure out the dead cells, and how to replace the dead cells?

And if Li-Po is a better alternative, what brand is "relialbe"?

Thank you again for your help!

Charge a pack up fully. Place it under a moderate load. Measure the voltage across each cell at the same time a load is placed. Cells should measure about 1.0-1.2v each under load. Any cell that is dead will read a non-consistant reading when comparing to the rest of the cells in the pack.

A better solution would be to make the switch now to LiPo.

I've mentioned Flight Power as a high quality brand.

Ryan

Lots of good lipos out there, flightpower, thunder power, air thunder, kong power, outrage... etc. Remember you'll need a charger capable of lipo charging.

Venom batteries have been well documented to contain poor quality cells that stop taking a decent charge very soon after purchase. Your battery is dead. Research which NiMh batteries are good on rc racing forums, buy a new pack, and all shall be good.

Has anyone tried the NI-MH batts that proboat sells for use in their Blackjack 26 brushless? If so are these actually good packs or should I go with duratraxx or IB's?

Thank you very much guys for your responses.

Yes, I think Vemon really sucks. I will never buy any products of Venom again.

My friend got Ni-Mh batteries of Pro Boat, but one of them has same problem as mine.

I think it's time to cahnge it into Li-Po, as Ryan said.

Thank you agains, boaters! Enjoy boating!

Hey what do yall think of the "platinum 2" 5000 mah lipo's from orion?

WHen I first got my SV27 I was using Venom batteries. At the time I thought wow the SV is pretty fast for a standard boat. Then I got some matched cells GP batteries. The difference was amazing. The performance was at least 50% faster again and the batteries got no where near as hot as the venoms. Like others have said, ghet some better batteries and you will be much happier.

Hey thanks for the motivation towards lipos as everyone else has said and continues to say. Still am curious about the best kind of ni-mh batts i hear that gp's are great althought i have no idea what gp's are. also does anyone know of an aftermarket aluminum or metal steerable drive system? if not i'm thinking about having one made at a local fab shop could also redesign it too. I have the BJ 26 brushless

You get what you pay for in hobby batteries, NiMH or LiPo. If you decide to go LiPo and go with a low-priced brand you may have the same problems you had with the Venoms. IME ThunderPower and FlightPower are excellent, high performance cells that last a long time - as long as you take care of them. LiPos are a bit more demanding of care than NiMH cells. As stated you must use a LiPo charger and follow the directions. You must not over-discharge LiPos or their life will be reduced dramatically. You must not get them too hot, and you must not run them when they are too cold. But if you follow the directions and take care of them, LiPos are head and shoulders ahead of NiMH cells in llifespan and power.

Do not even consider putting another steerable outdrive on the BJ cat. Steerable outdrives are put on RTR boats so that they will turn quickly in a small pond or pool. Once you speed up your cat, the steerable outdrive will cause hooking and spinning out, it will start to break parts, and it is very inefficient anyway. Aeromarine makes a nice upgrade kit for that model using quality flex cable drive and rudder. If you are interested in performance, forget the steerable outdrive.


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Check Hobby City as they have some good prices on Lipo's and you will get them as my Zippy 3000 two cells came in about 3 weeks and they work great. I use them in my sv 27 and they never get hot. WO