Maxx packs? Reciever packs?

[pitbull14218]

I think my batteries are tired, I need to replace my hump packs, 1 Is for my savage x the other Is for my hpi Nitro MT1.

I found them on eBay rated at 2500mah 6volt nimh, but they say AA not sure if that's not good?

Look at this on eBay http://www.ebay.com/itm/380744463868

 

[hamz9561]

I'd try it and go through several charge/discharge cycle on the charger just to be on the safe side...

 

[pitbull14218]

I'd try it and go through several charge/discharge cycle on the charger just to be on the safe side...

I was doing that but I was affraid to discharge them too low?

Also I was affraid they get to hot, my charge discharge settings do allow me to set time between charge discharges but I think it still went 1 After the other with no pause last time I attempted.

How warm is ok for batteries to get when charging discharging? I might pick up a temp sensor for the charger so I don't have to worry.

 

[hamz9561]

If you discharge that at 500mA for that capacity pack you shouldn't have any problems. It's okay if they get warm, just as long as it isn't too hot to place your hand on them for an extended period.

 

[pitbull14218]

If you discharge that at 500mA for that capacity pack you shouldn't have any problems. It's okay if they get warm, just as long as it isn't too hot to place your hand on them for an extended period.

I'm not sure if it's just that the battery pack is old but the shrink wrap on the one is starting to crack I think from getting too warm? I was able to hold them in my hand still but idk, I've been turning off the charger if it gets around 100 degrees.

 

[hamz9561]

If any of the cells in the pack appear to have swelled, stop charging/discharging immediately and dispose of immediately.

 

[pitbull14218]

What about going to a LIPO for the reciever/servo battery pack?

Compared to a normal 6v nimh?

Like this?

Look at this on eBay http://www.ebay.com/itm/361701896423

 

[hamz9561]

Unless you have a servo/RX capable of handling the 7.4 V of the LiPo, I'd say no without adding a voltage regulator. LiFE on the other hand is very popular type because it's similar to weight and performance of a LiPo but at a bit lower voltage 3.3 V per cell for 6.6 V for a 2S pack which should work with no regulator.

 

[pitbull14218]

So I decided after further research to buy a new nimh hump pack because I most likely cooked mine a little bit.

I guess some can be charged at 1c and others should be charged a bit lower maybe even 1/10C.

I was reading I shouldn't discharge them and recharge them, obviously a ton of mixed reviews but I definitely feel like my pack is tired and not charging properly, it was at least 5yrs old anyways, so pretty old, and stored for probably 4 years straight.

I also needed a bunch of other things some green slime, glow plugs, so should be good for a little while. Hopefully everything ships quick

 

[hamz9561]

The reason some people say that you don't need to cycle the NiMH packs is that they don't have the memory problem that they NiCd packs had. You can cycle them a few times though as diagnostic tool or to help a new battery obtain its full capacity (this is a trick I picked up from the racers at the local onroad track).

 

[ninnon]

I'd say no to a lipo to be honest. Just get a high Mah Nimh battery.

 

[cbaker65]

Some servo's can't handle high voltage ,I've fried 3 throttle servo's in my baja!
The 1/4 scale steering servo don't seem to mind the big receiver battery pack ,but
my throttle servo's are being snuffed by it!

 

[Certified Mike]

@pitbull14218. There should be a different setting on your charger for you to charge your nimh packs. There shouldn't be any '1C' settings involved with you charging the nimh cells or packs. These batteries use different methods of charging. This may have contributed to the downfall of your packs to begin with. May continue to cause issue as well. Def thumb thru the operating manual for the correct setting. (Sorry if I am mistaken but it doesn't sound right to me.)

 

[craig911]

@pitbull14218. There should be a different setting on your charger for you to charge your nimh packs. There shouldn't be any '1C' settings involved with you charging the nimh cells or packs. These batteries use different methods of charging. This may have contributed to the downfall of your packs to begin with. May continue to cause issue as well. Def thumb thru the operating manual for the correct setting. (Sorry if I am mistaken but it doesn't sound right to me.)

you can charge nimh at 1C some can even be charged at 2C but as a rule of thumb i would always go with a max of 1C

OP have you checked the capacity that your packs are taking,

i have 2x6v 1500mah hump packs in parallel 3000mah - 6V
a few times i have forgotten to turn off my truck and had them drop down to 1-2V last time it was on for 3 days yet they have charged up fine and taken a full charge to capacity,
i usually charge them at around 2 amp or 1C = 3AMp and have never had any problems

i wouldn't worry about the plastic shrink wrap becoming brittle/splitting or cracking that's what happens naturally with age and charging/discharging

 

[Certified Mike]

You can do it... Possibly, not questioning that... Just questioning if the charger has the separate nimh setting and if so, why not use it so there is no question about the way it charges? Was just a thought.

 

[pitbull14218]

You can do it... Possibly, not questioning that... Just questioning if the charger has the separate nimh setting and if so, why not use it so there is no question about the way it charges? Was just a thought.

It does have the nimh settings, and I've charged with those settings but the packs seem to get warm if I'm around 1c, so I decided to do it slower at like .6/.7 amps charge rate. Even then I stopped my charger at 1400mah charge of my 1600mah pack because it started to get warm, this was my new pack. I actually still need to try the pack out, been busy lately and haven't burned the nitro!

 

[hamz9561]

It's normal for NiMH packs to get warm while charging. As long as they are not hot, it should be fine to charge them on the correct setting.

 

[cbaker65]

It's normal for NiMH packs to get warm while charging. As long as they are not hot, it should be fine to charge them on the correct setting.

Remember back in the day when racers use to put their packs on ice!...LOL

 

[olds97_lss]

Almost always, the first thing I do in the spring before running is I drain my receiver packs completely, then charge them at 1A. Then I let them rest/cool and peak them again at .5A. To drain them, I use a 12V car brake light. I drain them until the light shuts off, then unplug and let them cool. Then throughout the season, I just peak charge them at .5A until the charger shuts off. Have used packs for years like this without noticing much degradation of performance or run time..

I never charge them at more than 1A though. They get fairly warm when draining and when charging. I don't pay much attention to it anymore.

 

[Certified Mike]

I guess I am confused about the settings on the charger... When you're charging in nimh mode, there shouldn't be a '1c' showing up... At least on the chargers I use. I understand that nimh use single and multiple cells... But in a pack, it may have a setting for Like '5 cell, 6 volts' type of thing... If I am just confused and I am wrong, just say so and I'll shut up. It just seems like you've had some difficulties using that charger. I remember looking at the manual for it... It is confusing. Seems that it's one of those manuals that was translated from Chinese to English using a program... So you run into things like 'use the plug from the plant of packing battery to the hose run charge good with finished happy FUN times'
Yah, totally got that, thanks!

Agreed btw, it is normal for an nimh pack to get warm... Just keep in mind that there is a difference between warm and being able to get bacon on it! Lol!
Yes, I remember putting my charger in top of my fridge and running the wire and battery pack in to the freezer!