A Great Charger, Set Up, & Battery Care

[Critterhunter]

OK, let's do some other settings and then charge the stock GT rechargeable pack. Incidently, if you have 8 AA nimhs or nicads you could charge them in the stock alkiline holder the same way (hooking up alligator clips to the main battery leads that connect to the GT), but that will be covered later. First, let's just set the nicad settings for what should work with most nicad batteries so it's ready down the road more than likely. You should still read this as things are explained that will apply to the nimh menue settings as well.

Press stop to insure you are at the main menu level. Hit the minus "-" key until you see Select Nicd Batt. Press Enter.

You'll see Nicad Charge Man Current X.XA or something similar. Press Enter and hit the plus or minus key to set it to 0.5A
Hit enter again to set it.

Hit the plus key and you'll see Nicd Discharge X.XA X.XV
Hit enter and set to 1.0A
Hit Enter again and set that setting to 0.1V and then enter.

What you have done is set the discharge rate to the max of 1 amp and that it will drain the pack to the lowest it can go at 0.1V

This would be a good time to note that, like the charging amp rate, based on the voltage of the pack the charger might not be able to drain at first at the full 1 amp rate until the voltage drops some. For the same reason when charging at high amp rates it might not be able to go that high in amperage and will show a lower amp rate. This is due to the max wattage raiting of the charger. Volts X Amps=Watts. When discharging for that reason it's faster to drain a pack with a car tail light bulb, and also because as the pack is near dead the charger will limit the amp draw to try to maintain a more true voltage reading, which really slows things down..

Hit + key and you'll now see Nicd Cycle DCHG>CHG X

This function will automaticly cycle (charge and discharge) a pack X amount of times to exercise it. I'd set it to the max of 5 cycles as when you want to exercise a pack for longer run times, health, and greater capacity you'll need at least that many cycles. If the capacity still is showing improvement after 5 then do several more. When you hit enter you can set it to either charge or discharge first, then do the other. Hit enter again and you can then set the number of times this is done. Obviously if you wish to come back when all the cycles are done and have the pack fully charged and ready then set it to discharge first and charge last. When the cycles are done it will then show capacity put back in/drained from each cycle and you can scroll through them using the + and - keys. To start the cycling after all is set just press and continue to hold the enter key until it starts. Note that I have found sometimes when a pack is drained to .1V the charger may think there is a connection break and stop things.

OK, nicad settings are set to what most packs should be fine to use. Now let's do the nimhs...

 

[Critterhunter]

Hit stop to get back to main menu, then - key to find Select Nihm Batt. and then press Enter.

Set all the settings to the same ones just discussed in the above Nicad submenu.

You could now choose any of the three functions to charge, discharge, or cycle a pack by moving to that function and pressing and holding the Enter key until it starts.

Let's cycle the stock GT rechargeable pack 5 times at .5 (half an amp) charge rate and a 1 amp discharge rate down to .1V as they should already now be set. Move things to a fire proof safe spot such as the middle of a cement floor. As a sidenote, when ever storing your packs somewhere make sure the two main battery leads don't come into contact with metal!

With your GT rechargeable pack sitting right side up (meaning the writing on top of the pack) and the main battery leads that connect to the GT facing you, the left terminal should be the positive and the right one the negative. Might be a good time to mark both with a magic marker for future reference on the plastic by them. Hook your positive alligator clip to the left one and the negative to the other. As noted before, you could charge rechargeable nimhs or nicads in the regular battery holder this same way. By the way, I believe this charger does have reverse polarity protection and so should notify you if the leads are reversed.

Get to the cycle function and set it to discharge first, then charge, 5 times. Then press and hold ENTER until it starts.

 

[Critterhunter]

The reason why we are not charging through the normal charge plug on the rechargeable pack is because there is a tiny charge circuit in there that won't let the charger "see" the pack and is only meant for the stock "charger".

If the charger says Connection Break more than likely you dont have things hooked up properly or there is a short in one of the connectors. I had a bad solder joint inside one of the banana plugs that plugs into the charger and had to melt back the plastic to fix it once. Another cause could be the pack is deader than a door nail and you are trying to drain it first, so truy charging first.

You will now see something like this as the cycling starts...

Nimh D/C (one of these will be flashing based on if it's charging or discharging) 0.5A XX.XXV XXX.XX (time taken so far) XXXX (capacity drained or put into the pack so far)

Note how the amps will go to 0 at regular intervals for a few seconds. This is normal. If you feel the pack is fully charged note the voltage when it's stable (when amps is on for about 30 seconds or so) and check it again in 20 minutes. Lower or same voltage might mean it's missed it's peak as discussed earlier in this thread.

While the pack is charging in either this cycle mode or in the normal charging function (use that and not cycle if you are only charging a pack and not cycling it...same for only wanting to do a single discharge...use that discharge function and not cycle) you can press the - minus key and scroll through settings to see where they are at. As you press the - key you'll see...

Nihm Sensitivity D.Peak 7mv/cell (what you should have set it at earlier)
Capacity Cut-Off OFF XXXXmah
Safety Timer OFF XXXmin
USB/TEMP CUT-OFF USB ENABLE
EXT TEMP. 0C
In Power Voltage XX.XXXV (This shows your input voltage level from your power source powering the charger)

To get back to the cycling charge/discharge screen just don't hit any keys for a few seconds and it will go back.

When the cycling is done the charger will show each cycle's capacity put in and drained out of the pack. You can hit the - or + keys to scroll through each cycle listing. You'll probably note more capacity each time it is cycled as this excercises the pack. This is good to do a few tmies a year, and as you cycle it if say after 5 cycles the pack is still showing gains in capacity then I'd keep going until it isn't showing gains anymore.

 

[Critterhunter]

Let's cover how long a this pack will take to charge or discharge. With the above settings since this is a 1000ma pack it should take a dead pack about two hours to charge (.5 amps or 500mah X 2=1000mah). To discharge at 1 amp it should take 1 hour, but as noted before the discharge rate is limited by watts, so it might not be able to do 1 amp until the voltage drops some, and as it gets near .1V the charger will also lower the amp rate to try to keep the voltage from dipping artificially under a heavy load. It may take several hours to drain to .1V for the above reasons, so figure on a couple of days or so to complete the cycles.

I prefer to drain it faster using a car tail light bulb. The bulb will get hot so put it on a cement floor. After the bulb goes out in say 20 or 30 minutes let it sit for another half hour or so to insure it's good and dead. Thjen just throw it on the normal single charge function as there is no need for cycle mode. When the charger is done charging it it will flash something like FUL or DON on the charge screen and you press a key. It will also play a tune when done for a few seconds.

Write down the capacity put back into it, discharge on the bulb, charge again, note/write down capacity. After 5 or so cycles if you aren't seeing further improvement then you can stop. As said, do this a few times a year to keep the pack in top shape.

Back to charge rates...Half an amp is fine and you can even charge at a full amp or higher when in a hurry as this would take an hour or less on a completely dead pack (feel the pack while charging....hot is too fast!), but when you have the time try to charge at slower/easier rates like say .1 amp for a roughly 10 hour time (no need to charge at a slower rate than that as this is real easy on the pack). Or say .2 amps for a five hour charge time, but .5 amp isn't really being hard on the pack or even at 1 amp here and there. Just go slower up to as long as ten hours when you can.

The other benefit to charging slower is you will get more capacity into the pack and longer run times. Think of it as pouring water into a bucket fast or slow. When you do it fast air bubbles get trapped in the bucket and so it is holding less water. Charging at say half capacity (500ma or .5 amps in this case) is fine and won't really hurt the pack, but charging at slower rates is even better for the pack and will provide longer run times than say 1 amp would. Always charging at 1Xcapacity (1 amp in this case) will shorten the pack life and cause it to hold less capacity over time.

Hoping Kered will now chime in with his setup/settings for the Excal batteries to avoid popping the thermal overload switch in those packs, along with connector set up. Not sure if this plug comes with the Accucel or if you need to buy it. Also, him or jim please chime in with your custom Etrac/Explorer rechargeable pack holders to charge them.

If anybody has any nimh or nicad specific charging questions for your machines now is the time to ask them too. After all that jazz is covered I'll down the road dive into setting up the lipo charging modes/how they work, and show you what packs you can buy and how to install them into a Sovereign. Want to kill off all the nimh/nicad stuff first and also cover the myths about getting less performance using rechargeables.

 

[kered]

I'll have to check my settings as its a while since i looked(set and forget), but i think i have the mv set at default and can charge up to 0.8amps although i usually charge at 0.4-0.5amps

 

[Critterhunter]

For the Excal battery? Probably as I think I remember you saying amnything .7 amps or higher would pop the thermal overload in the battery. If this happens to anybody out there, which will cause a connection break error, let the pack cool down and it should reset. Then charge at a lower rate. I don't trust the Auto functions on this or any other charger myself.

Since we've covered most of the nimh or nicad basics already you can now buy battery holders at Radio Shack for various size cells. A 9V battery plug will allow you to do those, C holders, D holders, 8AA or smaller ones of those like a 2 AA holder, 2 AAA holder for your TV remote, etc. Harbor Freight or Hobby King have cheaper batteries than Radio Shack. Walmart is a good source for 2500ma AA Energizers or higher. Read the label as they also have lower capacity ones you don't want. Buy your holders in series configuration, which most are.

So let's say you had a 200ma 9V nimh. I'd charge it at .1 amps (100mah). Energizer 2500ma AAs in an 8AA holder. Charge at .3 amps whenever you can, which will take around 9 hours...but at 1/2 capacity (1.2A) here and there is OK but harder on them. Remember, 1Xcapacity for one hour charge times is OK here and there, but feel the pack to see if it's getting hot and try to charge at 1/2 the capacity or lower up to say 1/10th cacpacity whenever you can for longer battery life. No need to go slower than 1/10th capacity. 1/2, 1/4th, etc is fine. Some in RC charge their nicads at like up to 5 or 10 times capacity which to me is insane but some packs are designed to handle that.

Next I'll cover trying to restore a bad pack and will try to dig up Jim and Kered's Etrac battery holders for charging, the Excal info, and Kered's pics/info on his lipo battery install. Any specific questions just ask.

 

[verylazybeachbum]

Critterhunter, I ordered the Turnigy Accucell 6 after reading your previous posts on the subject. Going through the setup step by step has been very helpful. However I am having some trouble using this charger with my Older Sovereign XS battery pack(shrink-wrapped pack made of 10 AA cells). Do the older Sovereign XS battery packs have the charging circuit built in?

When I have the charger set up as per your instructions, and I hold the enter/start button to start the cycle process (charging first, since it is real low), It says "Battery Check Wait...", then it shows for about a second the screen where it shows the volts and amps on the top, and timer and capacity on the bottom, then it cuts off and says: "Turnigy" and goes back to the setup screen (where I was before I started).

If this does have the built in charging circuit, is there a recommended place where I should cut through the shrink wrap to access the battery contacts? Or Is it possible I am having a different problem (could the pack be too low? I haven't used it in at least a year, and It may have been dead for a while, I realize this is probably an unwise practice). I am now cycling my aftermarket NIMH pack I bought for the Sovereign XS and It is working successfully, but it is possible that it was manufactured differently than the original pack.

Thank you in advance,

verylazybeachbum

 

[verylazybeachbum]

The Replacement NIMH pack wouldn't charge either. It would discharge 560 mah ( I thought it had more in it than that), and then stay on the discharge screen but at 0 Amps. When I stopped it and tried to charge it gave a Voltage Input error and stopped. Both packs must have the internal Circuitry.

verylazybeachbum

 

[FreeMan08]

if you have 8 AA nimhs or nicads you could charge them in the stock alkiline holder the same way (hooking up alligator clips to the main battery leads that connect to the GT), but that will be covered later. First, let's just set the nicad settings for what should work with most nicad batteries so it's ready down the road more than likely. You should still read this as things are explained that will apply to the nimh menue settings as well....

Critterhunter
First off, thanks for the work and research you've put into this thread. What I would like to know is, if NiMH batteries can be used in the GT 8 cell pack as at their best they are only 1.2 V, making the pack only 9.6 volts total. That's starting out on a hunt 2.4 volts low. At what voltage will the Sovereign GT start chattering because of a low battery?

 

[verylazybeachbum]

Oops, as it turns out, I think the power supply I was trying to run the Accucell from may have been bad. I am now hookup up directly to 12v and it is cycling another pack currently, I will try the Sov. XS packs again tomorrow.

One thing though, I don't know if taking a pack down to .1volt is a good idea. Maybe i'm missing something, but many batteries can be badly damaged if you go below a certain % of their total voltage. In the manual (on on the web) it lists the voltage cut-off level of NiCd cells at .85 v and NIMH at 1.0v. This is per cell, so if your pack was made out of 8 NiCd cells it would be .85 x 8 = 6.8 v for a cut-off voltage, instead of .1v. Is this right or am I totally missing something?

verylazybeachbum

 

[Critterhunter]

Yes, it sounds like you had a bad power source or you have the low battery power source alarm set too high.

Most in RC agree that draining a nimh or nicad all the way dead to cycle/excercise it is healthy for it. When the voltage gets real low the charger will lower the amp rate lower and lower until it only shows 0 volts, but it's still working. It does this to try to keep a truer voltage reading but it takes a long time to drain because of this. It also can't drain at a full 1 amp until the voltage drops some. Same deal with charging certain packs with many cells due to the wattage limit of the charger....volts of pack X amp rate charging or discharging = watts. I prefer to just drain it faster on a car tail light bulb, but if I plan 5 or more cycles and won't be around it for a few days I'll just let the charger cycle it.

By the way, when all the cycles are done hit enter and then plus or minus to scroll through the capacity drained/put back in each time.

I will be covering more excal/etrac/etc nimh/nicad stuff soon and then off to the lipos. Remember, never charge a lipo above 1C (1Xcapacity) or drain it below 3v per cell, which is 9V for a 3 cell series pack.

A good 2500ma or higher nimh 8AA cells should work fine in the regular holder but they must be peaked the day you use them. The GT cuts out at around 10.5V, but good cells often will charge higher than 1.2V per cell.

 

[Critterhunter]

For those of you looking for somebody to build custom Excal or Sovereign nimh or nicad packs for you check out cheapbatterypacks.com. They are highly used in the RC community by people who can't solder/build their own packs. I'm sure you could send them say your rechargeable pack holder and they'll custom install new cells. Click on the custom link or call them. They offer a large variety of high capacity cells to choose from, and I'd go with the highest capacity nimh or nicad you can find in that size cell. Note however that I think the stock GT charger is only like 50ma, so if you had them install say 3000ma cells in it that would take 60 hours to charge using the stock charger.

If anybody has them build them a custom pack please post the details on what you had done, how large of capacity, and how much it cost you.

 

[kered]

Hi Guys, sorry for my lack of input of late but i have been and still am very busy of late.

A just for your information bit
The XS rachargable has 10 x 2/3 size rechargable nicads at 700mah also a thermistor that limits charge on the charge plug but not on the pins
The GT has 10 x 2/3 size rechargable nimh at 1000mah also a thermistor that limits charge on the charge plug but not on the pins
The excalibur 1000 has 10 x 2/3 size rechargable nicad and is limited by the thermister and can only be charged through the pins unless you take it apart
The excalibur 2 has 10 x 2/3 size rechargable nimh and is limited by the thermister and can only be charged through the pins unless you take it apart
The etrac has 8 x AA rechargable 1600mah nimh in the stock pack and the limiting thermister limits on both the charge pin hole and the output contacts

The limiter cuts out at about 0.7-0.8amp charge rate when using the Accucel 6, if you charge through the main contacts you can bypass this on the XS, and GT factory packs but not the etrac or excalibur without taking them apart.

If you use rechargable AA's in either the GT, Etrac or Excalibur alkaliner holder you can charge them without taking them out of the pack, and you are not limited in any way by charge rate but don't go over 1C at the highest

Using critters method of discharging with a 12v tail light bulb i have recovered a variety of battery packs that were given up as dead, only thing to remember is leave the bulb conected for a few hours even when the light goes out otherwise the voltage will spring back up once disconected.

I'll leave it at that as i'm in a rush, i'll try to get on a bit ore often.

 

[Critterhunter]

Thanks for chiming in. I still need to dig up your old posts where you went into detail on charging the Excal battery and Explorer or Etrac's, along with the custom charge holder you built for the Explorer/Etrac. I remember you found how much of a charge rate you could do before the thermal overload for the Excal would kick in.

Draining cells dead on a car light bulb (faster than draining wiht the Accucel) and then charging at a high amp rate like 2 to 4 amps will recover a lot of packs as the high charge rate breaks down resistance crystals that form. It can be done by just draining/slow charging the pack several times but a high amp rate the first time helps desolve the crystals.

 

[Critterhunter]

I've put together a bunch of links that I feel would be useful to this thread's content. My contribution is a more broader knowledge of various battery types and chargers, but in terms of charging Minelab packs I stick to the GT for the stock pack or lipos. Kered has experience with particulars of the Sovereign XS, Etrac, and Excalibur packs when using aftermarket chargers to charge them, so I linked to his posts on that content as well for further details. You'll also find various other info in these links, such as Excalibur pod rebuilding, where to buy aftermarket higher capacity packs for it and the various Sovereign models, and so on...

This super long thread also has other info spread through it on various Sovereign (XS, GT, etc), Etrac, and Excal charging and pack info. This thread is beyond in depth but I guarantee you if you read it all not only will your head hurt, but you

 

[Critterhunter]

Just realized I never did post the 3 cell lipo charging details for this charger as an example with the 3 cell 750ma Rhino packs I use. Lipos are fine to charge at 1C (1 hour charge time) but as a general rule of thumb should never be charged faster than that. Some can but I don't. Who's in that big of a rush? Anyway, so that would be .750 amps max. Plug the lipo's molex (white) balance plug into the proper port. Plug the lipo's main battery connector into the charger's plug for that too. Selected the BALANCED charging mode on the charger. Make sure it's set for 3 CELL as this is a 3 cell series pack. Hold enter. It will confirm 3 cell set and what it's reading (which should also say 3 cell). Press enter again and away it goes. You can now hit the plus or minus key to change the screen and see the individual cell voltage of all 3 cells while charging. Useful to see how balanced they were when the initial charge is started. The charger will stop at 4.2V per cell or 12.6V (main screen) since this is a 3 cell series pack.

You might think a 750ma 3 cell lipo will have less run time then the stock 1000ma GT nimh pack. Not by my run time logs. You see, lipos hold the voltage very high until the very end of discharge (9V max drain), where as nimhs or nicads more steadily drop the voltage as they drain. The results are that a somewhat higher capacity nimh or nicad will probably trip the low battery alarm (which kicks in at around 10.2 to 10.5V on the GT and *probably* is the same for other Sovereigns or the Excals I would figure) sooner than a somwhat lower capacity lipo. I wanted max weight loss for my GT with my custom light weight shaft setup, so I opted for a 750ma lipo. Kered wanted max run time, so he opted for a 1450ma lipo that will still fit in the XS or GT battery holders.

There are 3 lipo charging modes. Regular charge (this does not balance the pack so do NOT use it as long as the lipo has a balance plug which most do.). Balance mode which you should always use. There is also a fast charge mode. This should be set at the same 1C charge rate. It doesn't charge it faster via a higher amp rate, but rather cuts off the charge near the end where normaly the current on a regular charge drops to a trickle trying to get the last bit of capacity into it. I only use that mode when I'm in a hurry, and again NEVER use a faster than 1C rate! There is also a Sleep "charging" Mode, but in reality this mode may drain or charge the pack depending on what it needs to do to get the pack to the proper sleep voltage. This mode will either drain or charge the lipo until it gets it to the proper voltage level for long term storage. When storing for months on end put it to sleep. I also always store my lipos in a metal box in the refrigeragtor. Make sure the metal box is painted on the inside so nothing shorts.

One other important thing: Make sure the user settings (first page of this thread) have been set right. Various lithium battery types need a certain default setting for them, which I cover how to set for lipos on page one. That's VERY important, as the wrong default lithium battery type can be a fire hazard.

If you open the GT's 8AA holder and slide off the slid and lift it off, you'll see a black and red wire. I just scraped off a bit of the insulation, soldered the proper JST tiny male plug (smaller than the deans Kered used for his lipos, as my lipos came with a tiny JST plug) to it, and then I melted a hole between the little chamber on the side and the main battery bay. That way the plug can reach into the main battery bay where I just sit the lipo, but I can still tuck the plug into that little side chamber (that chamber is where the "charge" circuit is on the GT's rechargeable pack but of course is empty on the 8AA holder) and use regular AAs in the holder if I ever wanted to do that for some dumb reason. NOT! As not only are lipos much lighter (even Kered's I'm sure is lighter than 8AAs), but lipos also don't self discharge on the shelf so they are always ready to go. Charging at 1C is not pushing a lipo but many think that is pushing a nimh or nicad and will shorten it's life, so they also charge fast and it's perfectly fine for them. About 1 hour on a dead (a pack that has been drained to no more than down to 9V of course) pack.

Now the WARNING: Lipos are great, light, high capacity batteries. They are also rather cheap these days from the right sources. Hobby King has my packs for like $7 a piece and I think Kered's were like $12. But, lipos require special care. Never puncture or short one. If you have to change plugs on one for some reason ONLY cut one wire at a time to prevent shorting, and solder that wire to the new plug before cutting the other one off the old plug. Always store in a safe metal container and charge in the middle of a cement floor, just like you should any battery, if you can't keep an eye on it (which you should do for any battery type when charging...keep an eye on it). Early on lipos got a bad rap because of fires while charging. The cause was they didn't have balance plugs or balance chargers back then. The cells would get out of balance and as a result one cell could be overcharged and thus a fire. These days they are really no more dangerous than using a nimh or nicad. Short a high discharge capability nimh or nicad pack for very long and you'll get a fire or explosion just like you will a lipo, and overcharge them and the same risks too. While a lipo is more at risk of being punctured and could catch fire from that due to it's non-metal hard shell used on regular batteries, unless you are in the habit of being clumsy like that they really are of no big risk any more than charging and using regular nimhs or nicads.

If you ever want to get rid of a lipo, cut each battery lead separately, mix up salt in a bucket of water, and throw it in there for several days to a week or so. It will drain the pack all the way dead and then far as I know is legal to throw in the garbage unlike nimhs or nicads. Look up the details for safe disposal on the web as I may have the details wrong.

 

[Critterhunter]

Wanted to add this bit of info from another thread in reference to the red light on the wall transformer for the GT (some have them, some don't) not coming on, and a bit more info on charging via aftermarket chargers...

If the red light is supposed to come on even if the pack isn't plugged in then that eliminates a bad pack and instead means the transformer is bad. Yes, always be around to keep an eye on things when charging any batteries, no matter what the type they are. I like to put mine in the middle of the cement floor in my basement or garage when charging. Nimhs, nicads, or lipos...Makes no difference. All pose a fire hazard if things go wrong while charging.

I think that wall transformer is rather pricey from Minelab ain't it? I know the rechargeable packs are for sure compared to what you can buy nimhs with about 2 to 3 times the capacity these days. If it is then I'd for sure get some good aftermarket charger. If you surf around you can find some good ones around $20 to $30, from simple plug and play ones to ones with many settings and the ability to do many battery chemistry types such as the Accucel 6. Whatever you buy, just make sure it's not charging faster than 1C (1 hour, or the amp rate of the capacity of the pack). In fact, I prefer something less than that like 1/2C for my "fast" charging and a bit slower when not in a rush. Just charge through the two main battery leads as there is a charging circuit in the GT's pack behind the plug. Actually, I think that "charging" circuit is really just a thermister and a diode and doesn't really do much else, at least if it's like the old Excal or older Sovereign packs. Reading some of Kered's posts on charging his XS and Excal packs refreshed my memory. He said they had a thermister to break the circuit if the pack got too hot. A cheap way to "terminate" the charge. The pack gets full, starts to get hot, and the thermister opens. Only problem is it will cool down and complete the circuit again and that on/off tripping will keep happening over and over again if the pack keeps getting hot. I suspect the Elite and GT's might be something similar but don't quote me on that.