Charger & Battery Help Requested

[TA-Mark 195]

Percymon: you weren't kidding when you said chargers/batteries is a minefield!

All,

While considering Li-Po batteries I've noticed that you can buy them with or without a receiver/servo connector - see here. Is there a consensus of opinion on which I should go with? Do you, for example, feed power to the receiver in the car directly from the Li-Po or instead use 4No. AA batteries? If the latter, do you use alkaline or rechargeable batteries?

Rob

That pack is designed for replacing the 4x AA cell receiver pack in a nitro vehicle or similar. On my 1:10 nitro cars I have 5 cell AA Ni-MH 2500mAh packs, 5x 1.2v = 6.0v. 4 cell Ni-MH is only 4.8v and a bit slow on the steering servo. On the larger vehicles like Savage and Baja 5B I use 5 cell 5000mAh Ni-MH sub-C hump packs. These reciever packs are too low discharge rate to power an ESC/motor.

It is a good idea to only use hard case Li-Po packs in vehicles. Soft packs are easily pierced by debris flung up off the wheels or can wear through the thin soft pack with the vibrations, especially if a rock gets caught under the pack. In the event of a hard crash a soft pack can deform from the impact forces. These sorts of damage to the pack can cause them to catch fire, then it's watch it burn and buy a new car.

In an electric car with an ESC, you plug the Li-Po into the ESC and the ESC supplies the reduced voltage for the reciever. Most have BEC ratings that are suitable for use with upto 3s, over that you need to use an external BEC unit so the reciever only gets it's needed 6.0v. High discharge rate packs (20C or more) are suitable to power the ESC/motor.

[Rob Buckle 1]

I plan on getting an ESC in the near future (will start a thread to discuss), but at present have the stock Clod Buster MSC. Is it still okay to use a Li-Po?

Assuming it is, if I understand correctly I am looking for a 2S (2 x 3.7v = 7.4v), hard case, 3000 to 5000mAh Li-Po battery with two leads (one to deliver power to the motor and potentially the receiver in the car, the other to ensure cells are balanced while charging/discharging) and that will fit the Clod Buster battery holder. I will then have the option of powering the receiver in the car with the Li-Po (BEC method) or from 4No. external AA batteries housed in the chassis. Is this correct?

Rob

[Rob Buckle 1]

Folks,

I plan on getting an ESC in the near future (will start a thread to discuss), but at present have the stock Clod Buster MSC. Is it still okay to use a Li-Po?

Have just been reading other threads re Li-Pos and it seems there is a danger of melting the wires of the Tamiya type connector of my MSC. Can anyone confirm that this is the case please, and that if so I will need an ESC to use Li-Po batteries?

Rob

[TA-Mark 195]

High voltage battery connectors are a very good idea with any pack. First thing I do with a new ESC or battery is to cut off the Tamiya plug and fit a ribbed deans plug (ribbed ones are easer to grip to get apart than the regular ones).

I'm pretty sure the Tamiya plug has a 7.5 Amp rating, and the Deans plug is 100 Amp.

There are other brands of high voltage battery connectors out there and there's threads here on the forums discussing the pros and cons of each.

It is possible to cut the Tamiya plug off the MSC and fit a better plug. Note that deans plugs require soldering.

[Rob Buckle 1]

High voltage battery connectors are a very good idea with any pack. First thing I do with a new ESC or battery is to cut off the Tamiya plug and fit a ribbed deans plug.

So the issue isn't the wires, but the connector itself?

[Percymon 2184]

So the issue isn't the wires, but the connector itself?

Correct, plus there's not much you can do with the wires without breaking into the battery pack itself.

[Rob Buckle 1]

Correct, plus there's not much you can do with the wires without breaking into the battery pack itself.

Thanks Percymon. Given that the latest posts in this thread touch on the subject of ESCs I'm going to start a new thread in parallel.

Rob

[Rob Buckle 1]

Folks,

I've decided to go with the Powerlab 8. I know its pricey but I like the increased safety aspect of it (especially with Li-Pos in mind) in comparison to alternative chargers. As noted previously by Mark, it'll comfortably handle any battery type I'll ever throw at it. It also does lead acid batteries (not sure if most chargers do or do not) which will be handy on occasion for my father, as his charger went missing some time ago (not guilty y'r honour!).

I'll be buying the charger and power supply from here but need some help (ASAP if at all possible as I'd like to buy before 16:00 today) with the additional options at the foot of the link. I am happy to forego parallel adapters at present and charge single batteries only. Questions:

1. Out of the Standard adapters (first two options in the link), do I need the TP/PQ or GP/KO type? Should I buy one of each?

2. Do I need 1 set of bananna cables (for one battery?)? Are these used to connect the battery to the charger (I understand that the balance cable also connects to the charger)?

3. I am intending to buy a basic NiMh battery to check that Clod Busters (2 No.) that I have refurbished are working properly before selling them. So, do I need 2 sets of bananna cables in total, one for use with Li-Pos and the other for NiMh?

Cheers,

Rob

[Rob Buckle 1]

Anyone?

[smegs 1]

Anyone?

Rob try getting a charger from hobbyproz I got a Thunder A6 and it a lot cheaper but works great.

[Rob Buckle 1]

All,

Charger etc on its way. I'm now turning my attention to the battery, specifically Vapextech li-pos.

1. Will I see a marked improvement in performance between the 25C, 40C and 45C (ignoring the fact that the 45C is 5000mAh whereas the other two batteries are 4000mAh). If so, how will this manifest itself?

2. If I buy the Tamiya TEU-103BK ESC, which I know is compatible with twin Sport Tuned motors, can I use li-pos if I change the Tamiya connector to a Deans connector?

3. Is it a problem that that ESC is rated for 7.2v and I will be using a 2S, i.e. 7.4v, battery?

4. Am I correct in thinking that I still need some kind of cut-off if I (am able to) use a li-po battery with this ESC?

Cheers,

Rob

[TA-Mark 195]

All,

Charger etc on its way. I'm now turning my attention to the battery, specifically Vapextech li-pos.

1. Will I see a marked improvement in performance between the 25C, 40C and 45C (ignoring the fact that the 45C is 5000mAh whereas the other two batteries are 4000mAh). If so, how will this manifest itself?

This current "C" rating is the discharge current rate. 25C means 25x the capacity of the pack, so a 25C 4000mAh is 100Amp discharge, 40C 4000mAh is 160Amp discharge, and 45C 5000mAh is 225Amp discharge.

The maximum possible current draw from 2x Silvercans is 120Amps (60Amp each), but this is with the motor under full load and stalled (motor not spinning at full throttle). Knowing that, you would expect to see no improvement in performance when using a low power brushed setup. You will see longer runtimes from the higher capacity pack. High discharge rate packs start to matter when you are running high current draw systems, like a brushless MambaMax Monster 1:8 Truck system and it's pushing something the size and weight of a HPI Savage (usually is powered by a large 0.28cui nitro engine).

2. If I buy the Tamiya TEU-103BK ESC, which I know is compatible with twin Sport Tuned motors, can I use li-pos if I change the Tamiya connector to a Deans connector?

I highly recommend you cut off any Tamiya connectors and fit a high current plug with any battery. The Tamiya connector is rated at 7.5Amp. A deans type plug is rated at 70Amp to 100Amp depending on brand. (Remember that each silvercan can draw 60Amps each at stall).

3. Is it a problem that that ESC is rated for 7.2v and I will be using a 2S, i.e. 7.4v, battery?

No problem at all. 0.2v doesn't make that much difference. I even run my Tamiya MFC-02 on 2S Li-Po.

4. Am I correct in thinking that I still need some kind of cut-off if I (am able to) use a li-po battery with this ESC?

Yes. It's a good idea to use some kind of external Li-Po cut-off or Li-Po low voltage alarm to use Li-Po packs. Taking a 2S pack voltage below 6.0v will irreversibly damage the Li-Po pack. You don't need it, but a few $ on an alarm/cut-off is cheaper than a new pack and it doesn't leave it to a guessing game on what voltage the pack is at. With low powered brushed setups it's very hard to pick the performace drop off to know when to stop driving without the cut-off/alarm.

[Rob Buckle 1]

Thanks very much TA-Mark.

I've ordered Deans plugs along with my charger and will fit one to a Tamiya TEU-103BK ESC when everything arrives. I have a soldering iron/solder etc though admittedly it's been years since I last used it. Nevertheless I'm confident I can solder a reasonably tidy connection. I'll order the 25C, 4000mAh battery from Vapextech and see how we go from there in terms of weighing up charge time, run time etc. This battery comes with a Deans plug pre-fitted so I don't need to worry about me potentially shorting the battery during fitting of a Deans plug, which is nice .

Thanks again,

Rob

[Rob Buckle 1]

Folks,

I recently acquired 3 NiCd batteries with a Clod Buster I have refurbished. I will be using LiPo with my own Clod Buster but this post relates only to the NiCds, which I intend to sell with 3 Clod Busters (not including my own ) I've refurbished.

Two of the NiCds are 7.2v, 1700mAh and the third is 7.2v of unknown capacity (the label, which is badly faded, states that it is NiCd but I don't see a capacity stated). For the two 1700mAh batteries, what value do you recommend I charge at? I've done a bit of research and found this post. I also found this (see below post for explanation of 1.4 factor). What do you think, should I charge at 5C? 5C would be 5x1.7=8.5A and would fully charge a flat battery in 12 minutes if my calculations are correct. This seems awfully quick.

What say you?

EDIT: for your information my charger offers the following two charge programs for NiCd batteries:

1. NiCd Fast Charge with Trickle

Basic NiCd Fast Charge with Delta Peak Cutoff and Trickle Charge. Requires manual

charge rate setting of between 10 mA and 20A, with default value of 1A. Can charge

from 1 to 21 cell packs. Fallback default setting is 8mV. Trickle charge rate is 1/20C of

the charge rate setting. Charge will timeout in 4 hrs if peak is not reached. Trickle

charge timeout is set for 1 Day. This preset is for constant current charging applications

only. Do not use this for Li, Pb, or other chemistries. Other defaults: discharge rate setting

is 1A, discharge voltage 1V/cell.

2. NiCd/NiMH 24 Hr Trickle Charge

Basic NiCd or NiMH 24 Hour Trickle Charge preset. Requires manual charge rate setting

of between 10 mA and 500 mA with default value of 100 mA. Can charge from 1 to

21 cell packs. Trickle charge timeout is set for 1 Day.

I had planned on using the first program

[Rob Buckle 1]

Folks,

In preparation for using my new Vapextech 5000mAh, 45C LiPo for the first time I wired it up to my charger, set the parameters - charge rate 5A; Generic Accurate LiPo Charge - stuck it in the LiPo safe and started it off. About 30 seconds later, having confirmed to the charger that it was indeed a 2S LiPo battery I intended to charge, the charger halted and displayed the following message:

Cell no add up. Use banannas?

I have the battery main wires connected to the charger via bananna plugs and am using the balancing port too. I'm certain I've wired everything correctly. Does anyone have any idea what the problem could be?

[Blacque Jacque 4]

Cell no add up. Use banannas?

Bananas.......Really ?

[Rob Buckle 1]

Funny guy, eh?

[Rob Buckle 1]

Is it possible I am using the wrong balance cable?

This link confirms that the battery uses a JST-XH balance connector. That is connected in turn to a GP (Great Planes) socket type for a 2S LiPo, shown here. I know for a fact the Kokam socket is the wrong size. However, there is always this board, which allows for Thunder Power and Poly Quest type connectors. The Thunder Power socket looks like it may be suitable.

Could this be the problem? Would that explain the error message?

[Backlash 481]

Hi Rob..

Not sure if you sorted this problem as yet, but I will try and assist you..

OK... I assume that you have connected the main battery lead (i.e. Deans connector) to the charger AS WELL AS the Balance connector.... You CANNOT charge the LiPo at 5Amps through those tiny wires fitted to the balance lead...

After double checking all of your charger settings, and ensuring that you have set the charger to charge a 2S LiPo, and that you have connected the battery leads and LiPo balance lead correctly, if it still wont charge the LiPo, then try charging a NiCd or NiMh battery to ensure your charger works...

I'm not exactly sure what charger you have, but it sounds to be one of those generic chargers that come in a number of different colours and brand names..

The "generic" charger I have has 2 LiPo charge modes, LiPo charge, and LiPo Balance charge... If you suspect that you have a problem with your balance socket or lead, then disconnect the balance lead, and try charging your liPo on regular LiPo charge mode.. If your Lipo starts to charge OK, then you have proven that you have an issue with your balance adaptor lead..

If it still wont charge, and if you have access to a multimeter, try measuring the output voltage of the LiPo at the battery connector.. (eg. Deans plug).. If you havent used the battery (if the battery is new) the voltage should be approx 7.4 - 7.8 volts.. If it is below 6 volts, then the LiPo has been over-discharger, and could be faulty..

Cheers

[Rob Buckle 1]

Hey Backlash, thanks for taking the time to help me out.

...I assume that you have connected the main battery lead (i.e. Deans connector) to the charger AS WELL AS the Balance connector...

Yes.

After double checking all of your charger settings, and ensuring that you have set the charger to charge a 2S LiPo, and that you have connected the battery leads and LiPo balance lead correctly, try charging a NiCd or NiMh battery to ensure your charger works...

Charger has confirmed that I am attemting to charge a 2S LiPo, so okay there. Regarding charging an alternative battery such as NiCd or NiMh, unfortunately I can't, as I now only have the one (LiPo) battery. However, I recently has NiCd batteries, which I charged without any problem whatsoever.

I'm not exactly sure what charger you have...

Cellpro Powerlab 8. It is a top class charger...when it's not refusing to charge LiPo's

...If you suspect that you have a problem with your balance socket or lead, then disconnect the balance lead, and try charging your liPo on regular LiPo charge mode.. If your Lipo starts to charge OK, then you have proven that you have an issue with your balance adaptor lead...

That's a good idea. My charger does allow charging LiPo without using a balance lead (though only up to 2S LiPo, presumably for reasons related to safety). I'll give this a try, but stop the charger if after a minute or so it appears to be charging without any problem - I am nervous of charging without using the balance lead.

If it still wont charge, and if you have access to a multimeter, try measuring the output voltage of the LiPo at the battery connector.

See this (point 2). Battery is definitely okay.

[Backlash 481]

OK, it sounds like you are doing everything right then..

Just googled your charger, and it is different to mine..

It could well be an issue with the balance board.. The one that came with my "generic" charger had an intermittent fault that would occasionally come up with an error whjen charging.. I eventually traced the fault to a faulty solder joint on the balance adaptor board.. Seeing as I only charge 2S LiPo's, I ended up making an adaptor lead to go from the charger to a male JST-XH3 connector by chasing out the pin configuration on the balance board with a multimeter..

Goodluck... Let us know how you get on with charging your LiPo in regular LiPo mode..

[Rob Buckle 1]

It could well be an issue with the balance board...

Hmm, well, not sure what to make of the following:

1) My charger allows a battery to be monitored either through the balance lead or through the banana leads. If I disconnect the banana leads in order to isolate the balance lead the charger reiterates that the battery is 2S, with 76% charge etc. However, if I then disconnect the balance lead and monitor through the banana leads the charger says I've connected a 1S (yes, 1S) battery. Eh?

2. When I attempt to charge without connecting the balance lead the charger reports that there is "No Pack", i.e. no battery connected. Eh eh?

It appears that the balance lead is okay from (1) above. Does anyone else think it could somehow be the banana lead (that I soldered a Deans connector onto, to connect to the battery)? The charger may have charged NiCd without any problems, but it wasn't using the same banana lead, but rather another banana lead I had fitted a Tamiya plug to.

Any thoughts?

[TA-Mark 195]

Test the lead you made. It is possible that one of the solder joints has come undone under the shrink (I've had this happen on a battery pack before). The plug on the battery may not be making contact to the plug on the charge lead too. I've had this happen when connecting deans style plugs from different brands.

[Rob Buckle 1]

I think we may have a winner!

With a bit of jiggery-pokery I managed to hook up the battery to the motor installed in the Clod gearbox - via the banana cable. When I contacted the Deans plug on the banana to the Deans plug on the battery, sure enough the motor started up...until I pushed the two Deans plugs together completely, whereupon the motor stopped.

Half connected - motor starts;

Fully connected - motor stops;

Not sure why this would happen when the Deans very obviously fit tightly together. Any ideas?

EDIT: It's the Deans connector on the battery! Going to change it now...

EDIT2: This would also explain why the ESC isn't getting power! Gettin' excited!

[Backlash 481]

Are you using genuine Deans connectors, or chinese copies?

I have had lots of problems with Chinese male Deans similar to what you have described.. (yes, I realise that your problem is with a female connector)

Just be careful not to overheat the pins when soldering the wires to them, as you often melt the plastic, and cause a misalignment with the pins..

Cheers