lipo charger ?

[iplaywithrocks]

I did a bit of reading and still have a couple of questions.

What is the advantage of chargers that require a separate power supply versus one that has a built in one?

Are chargers that service all battery types less stable versus a lipo only charger or a nimh/nicd only type charger?

i have a very old mrc superbrain. its a red light blinks kinda charger .
i have not used it in awhile and only really charged a 1500 pak for the starter hpi supplies for thier nitro engines.

i used this charger on a venom power 5000 mah nimh battery i purchased at my lhs and put it in my wraith and found the run time pretty disappointing . maybe 15 mins? The directions the hobby shop gave me where plug in the battery run it till its dead and charge it again and due to the wraiths crawler style speed i should get 40 mins out of the pack.

i gave them a buzz and they then told me to charge the battery until light goes off. unplug battery and charger , plug both back in and repeat this process till battery feels warm. Does that make sense? Sound like sound advice?

I plan of getting a new charger and batteries but would like to continue with
nimh when im goofing off with my son and a lipo for when he grants me an hour or two of free time to goof off myself

any advice ,help or clarification would be huge! thanks again!!

[happymachinist]

The world of chargers is one full of options and even more opinions. It all depends on what kind and size of batteries you have and also what kind and size of batteries you think you might get down the road.

RCs come and go but if your in the hobby for the long haul might as well get a good charger now...based on what you can/want to spend.

Features I'd look for is:
1- multi chemistry
2- storage feature (charges lipos to 3.85v ish and stops)
3-discharge is nice but not fully necesary
4- ability to charge more than one at a time

I personally have an onyx245 and a powerlab6.



The onyx245 is good because its like 2 chargers in one case. It can charge 2 different chemistries, voltages and sizes at the same time. It is only rated to 3s though. It has a port to charge rx batteries for nitros and comes with deans, traxxas, and the old school white tamiya (I think...it's the plug for a traxxas EZ start batt) adapters. It comes with the balance boards for lipos. It has an internal power supply, and aligator clips to run from your car battery if out and about. It does not have discharge or storage features but that can be overcome. It also times out after 90mins so if you plan on getting batteries larger than 5000mah it could time out before a charge is complete...not a big deal just more of an FYI...you just have to restart it. Overal I'm happy with it, it's simple to use and hasn't let me down yet...it's just too small for my other charging needs.




My powerlab6...is excessive for most crawler applications and requires a little more battery understanding. It doesn't come with any adapters and needs an external power supply. Nice features include storage feature and the ability to discharge. I can monitor IR of each cell and it has PC interface that allows me to create in depth presets for common batteries I charge. It's high amperage capabilities means in theory I should be able to parallel charge 6 2S 6000mah lipos at once (1C) but I haven't tried it yet...

Of the 2 chargers I have I'd recomend the onyx first from the info you've given thus far. Not saying its the best but it would be the more logical of the 2 I have.







Sent from my iPhone using autocorrect

[Trubble]

Originally Posted by iplaywithrocks

What is the advantage of chargers that require a separate power supply versus one that has a built in one?

Most internal power supplies are limited to 50 watts, generally. This will limit you to roughly 5.9 amps when charging a 2S, and about 3.95 amps when charging a 3S LiPo. You can still charge 2S's more than 5,900mAh, and 3S's more than 3,950mAh on these chargers, but it will be at less than 1C charge rate (just takes longer than an hour to charge if you go less than 1C).
Chargers that don't have an internal power supply rely on the power supply you provide to be robust enough for the charge rates you hope to achieve. D/C only chargers (without an internal supply) generally do have higher amp limits than ac/dc models, but they still have top limits. IIRC, my Onyx 230 will max out at 7 amps, but will only get to the above mentioned 5.9 amps when running it on AC. (limited by a power supply that's designed to be small/light and cheap)


Are chargers that service all battery types less stable versus a lipo only charger or a nimh/nicd only type charger?

Not necessarily.


i have a very old mrc superbrain. its a red light blinks kinda charger .
i used this charger on a venom power 5000 mah nimh battery i purchased at my lhs and put it in my wraith and found the run time pretty disappointing . maybe 15 mins? .......... and due to the wraiths crawler style speed i should get 40 mins out of the pack.

Could have been a false peak. If your 5,000 was a new pack, give it a couple charge cycles to get all the cells equalized.

Could have been you had your LiPo LVC on (auto-LiPo), and it kicked in.

Could be that with a large (heavy) vehicle with higher gearing (as opposed to a more true 'crawler'), and a lower turn motor have all conspired against you to steal away run time. My AX is a LOT lighter than yours, and came geared 14/87, and had a 55 turn motor. It also had near zero ground speed, but, very low amp draw, which gave me nice long run times. You could try gearing down a bit, but that'll generally kill off ground speed a LOT more than it'll pick up run time.
If one of the other two scenarios above aren't occurring, personally I wouldn't get too overly hung up on the 40 minute promise, especially if you're running NiMh packs. Fifteen mins does seem a little short for a 5,000, but for more of a go-fast type of vehicle I don't think you're too far off the mark.


i gave them a buzz and they then told me to charge the battery until light goes off. unplug battery and charger , plug both back in and repeat this process till battery feels warm. Does that make sense? Sound like sound advice?

Yes. On a simple charger like you have, that's how you'd restart the charge when it false peaks. And yes, when a NiMh/NiCad reaches fully charged, any attempt to continue charging will result in excess power being given off as heat energy. So when they're warm, they're done. I highly recommend letting them cool off after using (don't immediately put them on the charger while still hot), and if they come off the charger hot, let them cool down before using in your truck.


any advice ,help or clarification would be huge! thanks again!!

I run an Onyx 230 with a charge-through balancer, and charge my smaller packs through the balance connector, larger packs through the main plug. Were I to splurge buy another charger, I might go with one of Hyperion's EOS 0720i NET3 chargers. But for you just starting out, I'd say do some research on the Onyx 235, Hobbytown's Radient Ascend, or the AC6.

[iplaywithrocks]

Thank you both for your replies. Im looking into the chargers mentioned .

[iplaywithrocks]

I followed the hs recommendation of restarting the charger . I did it 5 times and the 5000 mah battery worked much better . Run time was amazing . with these nimh batteries when they no longer move the wraith on the ground is it time to charge or should i let it run off the ground until the wheel stop completely ?

[Trubble]

To be quite honest, you really shouldn't even run it down that far. Check up and stop running a little sooner in the future. While, yes, NiMhs can handle being run clear down like that and won't destabilize like a LiPo, you're still doing some internal damage. I'm not saying stop after only three minutes, but I'd recommend stopping before it won't move.

And running the battery out w/ the truck up in the air absolutely will do permanent irreparable damage to the battery, and also you stand to increase the potential for wear and damage on your truck too.

[iplaywithrocks]

sweet thank you for the reply ! alot different then nitro but i find i can use this truck a lot more often . Cant wait to try lipo seems people find it to be a religious experience .