Batteries And Chargers

[Malakite]

Hi guys,

OK I will be ordering my first new Tamiya kits (the first time in about 20 years and im really excited!!). I just wanted to ask advice on the best batteries (7.2V) to buy and the best quick charger to get for them? I know the more 'Milliamps' the batteries the longer they last (i.e. 3600 will be better than a 2600 for example) but i'm not sire the best brands etc and what to look for and what to avoid. Also is it still the case that you need to run a 'slow charge' once in a while with the batteries too as quick charges always fry them? Whats the difference between cheap and expensive chargers? Any names of models and link would be greatly appreciated. I have done as much reading as possible on the subject but info only seems available on each charger as opposed to telling you what to look for etc!

Many thanks as always

[taliesin]

duratrax makes a nice nimh 4200 mah battery pack for under $40. good quality and long run time.

i have 3 chargers. each has something good/bad. questions for you to consider:

1. will you ever want to upgrade to lipo?

2. if so, do you buy a charger now that can handle them or wait til later?

3. 1 battery at a time or 2?

4. where do you need it? ie, home or track? AC or DC?

5. discharger built in or not?

6. how much info, or how many set up options do you want to see/mess with?

7. how much do you want to spend?

8. how much control do you want over charge rates? ie, automatic = easy, but not always optimal, OR manual = better, but fussy and you do the work

lots to think about, i know.

i got a 2 battery auto select charger to fast charge my stick packs for the emaxx since it takes 2x batteries at a time. its fast & easy, but false peaks fairly often and isn't great on the stick packs lifespan.

i also got a basic prophet. i select the amp rate from 1, 2 or 4 amps. works great, but absolutely no features at all. no discharger, no options, nothing.

i also have a duratrax piranha. nicer features, totally programmable, shows me the battery health, lots of options. no discharger still, and won't do lipos.

you can pick and choose the features and price that are important to you. i probably have enough invested now in 3 different models, i could have bought the mercedes benz of the lot and saved money. at least i can do 4 batteries at once now.

[Malakite]

duratrax makes a nice nimh 4200 mah battery pack for under $40. good quality and long run time.

i have 3 chargers. each has something good/bad. questions for you to consider:

1. will you ever want to upgrade to lipo?

2. if so, do you buy a charger now that can handle them or wait til later?

3. 1 battery at a time or 2?

4. where do you need it? ie, home or track? AC or DC?

5. discharger built in or not?

6. how much info, or how many set up options do you want to see/mess with?

7. how much do you want to spend?

8. how much control do you want over charge rates? ie, automatic = easy, but not always optimal, OR manual = better, but fussy and you do the work

lots to think about, i know.

i got a 2 battery auto select charger to fast charge my stick packs for the emaxx since it takes 2x batteries at a time. its fast & easy, but false peaks fairly often and isn't great on the stick packs lifespan.

i also got a basic prophet. i select the amp rate from 1, 2 or 4 amps. works great, but absolutely no features at all. no discharger, no options, nothing.

i also have a duratrax piranha. nicer features, totally programmable, shows me the battery health, lots of options. no discharger still, and won't do lipos.

you can pick and choose the features and price that are important to you. i probably have enough invested now in 3 different models, i could have bought the mercedes benz of the lot and saved money. at least i can do 4 batteries at once now.

Thanks for the advice. What would the Mercedes Benz of the lot been then and how much?

Also if I were looking for an automatic quick charger that can do either one or two at a time, and can discharge, what would I be looking at/for?

Are Lipos the next generation of battery to hit the market soon then? If so when are they due and is it worth getting a charger that does these too? I guess the answer to that is yes right?

[terry.sc]

You get what you pay for with batteries. The main difference is capacity, but the cheaper battery packs can't give out the power like the better quality packs do. Then again unless you are using much hotter motors than what comes in the kit you won't notice the difference. At the cheap end Vapextech batteries have a good reputation, but just about all batteries are good these days, just avoid the really cheap ones.

You don't need to run a slow charge through modern packs, if anything it has been known to damage them. Discharging them fully before charging does help extend their life though and any decent charger will be able to discharge them as well.

Cheap chargers just do that - charge. The really cheap 20-30 chargers are simple chargers that charge at relatively low rates (so it takes longer to charge) and will get power into the batteries. Cheap ones also all seem to have a cut off timer built in as a safety feature, which means with higher capacity batteries you might have to restart it to get the pack fully charged.

Spending a bit more will give you a charger that can charge at higher rates and have a digital display so you have some idea of what is happening, such as how much power has gone into the pack. They can also discharge the packs before charging and quite often have the ability to charge lipo batteries as well.

At the extreme end the ProTrak enables you to hook your cells up to a laptop and get a set of charge/discharge graphs for each individual cell, will charge and/or discharge every cell individually and even run in your motor. It will cost you 196 or 242 with all the options.

I presume you will want a 240v charger, so you don't need to charge from 12v. In which case I would recommend the Graupner Ultramat 14 A bargain at that price, a few of them are used at my club, they are reliable and allow Lipo charging as well. It's what I would probably buy myself if I was after a new charger. If you want something to charge from the mains then make sure you buy it in the UK, buying over here also means if anything goes wrong it can be repaired. Buying electronics from abroad means you will have to send it back there if it goes wrong.

Lipo batteries have been around in r/c cars for about 3-4 years now. The big advantage is they can be charged one day and left until you need to use them, they don't go flat like other types. The batteries are lighter and being 7.4v instead of 7.2v they give you more speed. The downside is to prevent you overdischarging them you really need a lipo compatible ESC or a cutoff device. You can get away without, but if you run the lipo pack too low it will not charge up again at all. If you are considering lipo make sure you get a battery which has a hard case around it, there are cheap ones that aren't designed specifically for cars, these are without a hard case and they tend not to last too long before being damaged. I would stick to normal batteries for now but buy a charger with the option to charge them for the future.

[Buckjaw]

As a fairly new guy, I picked up a Piranha peak power charger with (2) 1800 6 cell batteries, awhile back on ebay. They were used but in great condition. Im very happy with what I got, for a cost of about $45 with shipping If I remember correctly. May not be the best but it surely aint the worst. Always looking for a deal!

[HunterZero]

My charging weapon of choice is the Duratrax Ice. It's good, only drawbacks are it needs a separate power supply, and the discharger could do with allowing the discharge rate to be set higher.

For batteries, they're all made up of sub-C cells. The cells in most packs will be from one of a handful of cell manufacturers - Sanyo, GP are the main ones that come to mind. 4000mAh is going to give you a lot of run time, unless you're running a pretty wild motor.

Not all cells of the same rating/brand/type are created exactly equal, there's a bit of variance. You can pay more for 'racer' packs and battery kits that are pre-tested to ensure all the cells in the pack are 'matched', and are of top end quality/spec, rather than the run-of-the-mill packs that just use random cells. But truth be told, the difference will only be noticeable if you're racing at the top levels.

- James

[Malakite]

You get what you pay for with batteries. The main difference is capacity, but the cheaper battery packs can't give out the power like the better quality packs do. Then again unless you are using much hotter motors than what comes in the kit you won't notice the difference. At the cheap end Vapextech batteries have a good reputation, but just about all batteries are good these days, just avoid the really cheap ones.

You don't need to run a slow charge through modern packs, if anything it has been known to damage them. Discharging them fully before charging does help extend their life though and any decent charger will be able to discharge them as well.

Cheap chargers just do that - charge. The really cheap 20-30 chargers are simple chargers that charge at relatively low rates (so it takes longer to charge) and will get power into the batteries. Cheap ones also all seem to have a cut off timer built in as a safety feature, which means with higher capacity batteries you might have to restart it to get the pack fully charged.

Spending a bit more will give you a charger that can charge at higher rates and have a digital display so you have some idea of what is happening, such as how much power has gone into the pack. They can also discharge the packs before charging and quite often have the ability to charge lipo batteries as well.

At the extreme end the ProTrak enables you to hook your cells up to a laptop and get a set of charge/discharge graphs for each individual cell, will charge and/or discharge every cell individually and even run in your motor. It will cost you 196 or 242 with all the options.

I presume you will want a 240v charger, so you don't need to charge from 12v. In which case I would recommend the Graupner Ultramat 14 A bargain at that price, a few of them are used at my club, they are reliable and allow Lipo charging as well. It's what I would probably buy myself if I was after a new charger. If you want something to charge from the mains then make sure you buy it in the UK, buying over here also means if anything goes wrong it can be repaired. Buying electronics from abroad means you will have to send it back there if it goes wrong.

Lipo batteries have been around in r/c cars for about 3-4 years now. The big advantage is they can be charged one day and left until you need to use them, they don't go flat like other types. The batteries are lighter and being 7.4v instead of 7.2v they give you more speed. The downside is to prevent you overdischarging them you really need a lipo compatible ESC or a cutoff device. You can get away without, but if you run the lipo pack too low it will not charge up again at all. If you are considering lipo make sure you get a battery which has a hard case around it, there are cheap ones that aren't designed specifically for cars, these are without a hard case and they tend not to last too long before being damaged. I would stick to normal batteries for now but buy a charger with the option to charge them for the future.

May thanks for this great post! I think I will buy the charger you have sent the link on. As you say it seems to do everything, but does it discharge also? I couldn't see where it said it did?

Also would you mind sending me a good link for batteries please? When you say the 7.4, is that bigger than the 7.2v of old? I ask as I am going to buy a couple of old Tamiya re-re's, andwouldn't want to get a 7.4 new one and discover they don't fit!

Many thanks

[terry.sc]

As you say it seems to do everything, but does it discharge also? I couldn't see where it said it did?

No, it doesn't discharge batteries, but just using a charger to discharge the complete pack will not make any difference to performance. To properly discharge and balance the cells you need a purpose built discharger that will discharge cells individually.

When you say the 7.4, is that bigger than the 7.2v of old? I ask as I am going to buy a couple of old Tamiya re-re's, and wouldn't want to get a 7.4 new one and discover they don't fit!

The new Lipos come in a hard case that is the same size and shape as a racing pack of side by side NiMh cells. This means they fit perfectly in high end chassis, but they don't fit in any chassis designed for a normal stick pack battery.

[Backlash]

The new Lipos come in a hard case that is the same size and shape as a racing pack of side by side NiMh cells. This means they fit perfectly in high end chassis, but they don't fit in any chassis designed for a normal stick pack battery.

As Terry has suggested, the 7.4 Volt packs would be LiPo's.. You can get hard case lipo packs that will fit in the Tamiya cars that require a "stick pack" battery, see this thread here... http://www.tamiyaclub.com/forum/index.php?showtopic=42798

I have just bought 2 x of these Yeah racing LiPo batteries, and they fit into my M03 Mini Just fine.. The ridges on the bottom of the pack mean that they also fit into the battery slots on my TC5 as well..

One thing, if you plan to use LiPo batteries, you will need to get a charger that is capeable of charging LiPo batteries, and also a Low Voltage cutoff for your ESC (if it doesnt have an internal one) such as the Novak Smart Stop..

For a suitable LiPo charger that will also charge NiCd and NiMh, do a search on eBay for "IMAX" ..

Cheers

[HunterZero]

Duratrax Ice has a large LCD with charging graph, has a discharger and automatic battery cycler program, different charge programs and battery profile memory, does charge Li-Po and Li-Ion as well as NiCd and NiMh, and has an optional temperature probe that can be used to shut down the charge if the battery gets too hot.

Well worth a look, I think it's about the best charger for the money. My only complaint is that the discharger could be a bit quicker. Oh, and it would be nice if the screen was backlit too, but it's not.

Duratrax Ice

that Graupner one looks pretty decent if you just want a 240V mains charger though.

- James

[Malakite]

Hi guys and thanks as always for the advice. So am I right in thinking that I don't actually need a discharger for any reason? If so whats the point if it doesnt help the performance of the batteries? Also the ICE charger doesn seem to have a price?

If anyone could send me a link on lipos and the normal batteries to purchase, that would be great. I think i'll buy one or two of each and see if I can notice any difference between the two? I would like 3300 or above (if they exist?) as that would mean longer running time which would be great

Also do ESC make a difference to the life/running time of a battery to compared to a manual one?

Thanks as always

[TA-Mark]

If you want quality in Li-Po there is only 1 name. Apogee. They make some nice packs, but they aren't cheap. Google around will find other brands.

To run a motor from a Li-Po it needs a high discharge rate, like 20C. Low discharge rates (2C) are only suitable for RX/TX power.

[HunterZero]

Hi guys and thanks as always for the advice. So am I right in thinking that I don't actually need a discharger for any reason?

Well, an RC car is an effective battery discharger

So no, it's not essential to have one. You can build one yourself fairly cheaply if you have the tools using auto globes, if you're keen.

Also the ICE charger doesn seem to have a price?

Tower Hobbies has them for $125, but I am sure you could find one for a bit cheaper if you shop around. I have seen them for about $120. The problem is you'll also need a desktop 12V power supply that can supply enough current, at least 12A, which could run another $100 or so.

Also do ESC make a difference to the life/running time of a battery to compared to a manual one?

ESC vs MSC = no comparison. ESCs are far more efficient, give better control, can handle hotter motors and are far less prone to glitches/problems than the mechanical MSC equivalent.

- James

[Malakite]

Well, an RC car is an effective battery discharger

So no, it's not essential to have one. You can build one yourself fairly cheaply if you have the tools using auto globes, if you're keen.

Tower Hobbies has them for $125, but I am sure you could find one for a bit cheaper if you shop around. I have seen them for about $120. The problem is you'll also need a desktop 12V power supply that can supply enough current, at least 12A, which could run another $100 or so.

ESC vs MSC = no comparison. ESCs are far more efficient, give better control, can handle hotter motors and are far less prone to glitches/problems than the mechanical MSC equivalent.

- James

OK, so do the new Re-res come with ESCs as standard? Thanks

[HunterZero]

OK, so do the new Re-res come with ESCs as standard? Thanks

Depends on the kit, and where you get it.

Most TT-01 kits and re-issue kits do come with a basic Tamiya TEU-101BK, if bought outside Japan. They have a yellow sticker on the box to indicate one is included. You'll need a radio receiver that supports BEC to use this ESC, and it doesn't support faster motors as it's only rated for the standard 540 and sport tuned motors. You're lucky if it runs with a 23 turn. The versions of the kits sold in Japan typically do not include an ESC.

Kits like the DB01, DF03, TA05 and TB-02 and all high end kits do not include an ESC.

- James