Ni-MH Batteries

[adler]

Hi Guys

I've been disappointed with the running time from standard Heng Long supplied batteries - less than 15 minutes running on concrete and short grass.

I've tried charging for different lengths of time and also running the batteries right down but have obtained no improvement.

So I'm thinking of buying a Ni-MH battery - 7.2V 3800mAh but I think I'm sure I read somewhere that they require a different charger from the standard HL ones. Is this correct? If so, what type of charger is it?

Thanks for your help.

Dave

[Johnf]

I use the 3800 amh battery and running time is fine. Also have elmod which is heavier drain than the rx18. I imagine you could use the stsndard charger but will need longer to charge. I would advise you to dump the heng long charger anyway and invest in a smart charger. Forgebear has some i believe. The heng long if forgotten about can cause a fire and ypu never know for sure if you have a full charge. The smart charger will fully discharge then charge and will switch to trickle charge when fully charged. Much better,safer and better for your batteries also

[Jason001]

I use the standard heng long batterys and get about 40 to minutes out of them.
I get that whether i quick charge them or slow charge them. I have a total of 3 batterys and there all the same.
If your only getting 15 minutes run time i dont know what to suggest, but it doesnt sound right to me.
Jason

[caddyshack]

JohnF gave some good advice about getting a better charger. Thats one point some poeple over look.
The others are..how good the battery is as you have been using the Hl chager it may not even be getting a full charge. The reason why we, fully discharge then charge the Ni-Ah is they get a memory point on them and a discharge removes that point.
The other is how well you ran your motors in. If you (out of the box) full throttle them,and didn't ease them in. Then they probably have some "blue effect" around the bushes. A motor needs longer to run in than most people think.That is not going to help in your run times.

[Tankbear]

I use the standard heng long batterys and get about 40 to minutes out of them.

Same here. As mentioned look at getting a better charger with a at least auto turn off, I bought a basic charger for about £8 output is 1000mA or 1A so chargers the standard HL battery in under 2 hours.

If you've a digital voltage meter you can measure the voltage of the battery after recharging you should get get between 7.6v and over 8v. (sorry can't remember actual figure)

[adler]

Thanks for that guys.

Dave

[Jason001]

I noticed the other day that some of the Heng long standard motors are faster than others.
I have one set of motors that turn my kv-1 into a grand prix vehicle and that drains the battery in about 15 minuters.

I changed the motors over to another set of motors that run the tank at a more sensible speed and the battery than lasts around around 40 minutes(I think that set of motors cames with the steel gearbox I bought from forgebear).

Maybe this is why your batteries draining so quickly?

Jason

[caddyshack]

As i put in my post above..motors as in the brushes need bedding in. Blast away from the off will give you a poor performing motor in your tank, that will help drain your battery quicker than they should.

[Jason001]

Thanks caddyshack.

Question: What do you mean by blue effect?

Jason

[Bigwheels_inc]

The Std heng long charger is made for Ni-Cd batterys and they will not work with 3800mah batterys,
the 3800mah batterys are Ni-Mh which require a charger that will charge Ni-Mh batterys,

the problem comes with the chemicals used in the batterys,
the Ni-Cd batterys are very old style and have a big memory effect which is why they should be fully charged and fully drained every time you use them otherwise you end up getting batterys that only half charge, E.G. if you put a half charged Ni-Cd battery on charge it takes it as the battery is flat and will only charge the battery 50% of it max capacity and then it remembers that the battery holds 50% charge & the more you do this the more it has a big effect on the batterys performance,

the Ni-Mh batterys are a newer design and have virtully no memory effect so if you put one on charge even half full you end up with 100% charge because the battery does not remember ever being charged,

the biggest problem is that they charge diffrently and if you use the std heng long Ni-Cd charger on Ni-Mh batterys it will create a massive memory effect in the Ni-Mh batters which destroys the Ni-Mh batterys very quickly,

so get the right charger for the type of batterys you intend to use

I hope this helps

Pete