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Asked — Edited
Resolved Resolved by DJ Sures!

Long Life 7.4V Lipo Battery And Charger For Ez-B V4

Hi everyone.

I need a little advice in regards to LiPo batteries for the EZ-B v4. I have been waiting for my dev kit, balance charger, 7.4 LiPo, and a few extras to be delivered for quite a while now, and after I sent of an email to the very helpful EZ Robot guys and gals inquiring what the delay was, it turns out that there is a shipping issue with sending loose batteries from China which has been holding up my order being sent. I have requested a refund for the LiPo and charger which has been honored, so no problems there.

So what I need the community's help with is advice on what I can safely use with the EZ-B v4. Can anyone recommend a good, reasonably priced LiPo battery pack that can hold a long charge, say about 2500 mAh or more that will work well with the v4, and a good charger to go with it? A balance or auto cut off charger would be preferred as I hear that LiPo batteries can be a bit finicky and care needs to be taken to avoid killing them.

Any advice or recommendations anyone can offer would be greatly appreciated.



United Kingdom

Thanks for your informative response. I stand corrected about my "step backward" remark *blush* (although I did say "in some respects").

I take on everything you said about longer capacity, smaller/lighter ect, and "step backwards" was probably the wrong phrase to use. It's just taking the extra care not to let the LiPo's fully discharge and remembering to recharge them before they completely drain, even keeping them charged if you don't use them for long periods of time, and seeing £20 or £30 go up in smoke if you forget.

But as yourself, djebay, and others have said, you have used them for a long time now with no issues, so fair play to you, and I am probably over thinking things (as I sometimes do) *eyeroll*


Thanks for the link you supplied. Very interesting and is a good read.

United Kingdom
My EZ robot goodies have been delivered today :D:D:D

So now I need to order my battery and charger. While I have been looking for a battery to buy, I am seeing that there are different connection types. Which one do I need to connect to the EZ-B v4, I do I cut the connector that comes with the battery off, and attach the barrel jack that comes with the dev kit to the battery?

Steve. *confused*
If you just have the ezb with power shell you will need a barrel connector... Yes, you can snip off the aa pack barrel connector that came with your development kit... Just be aware of the polarity when soldering it to your new Lipo...
this what i did from battery to adapter.

User-inserted image

to charge i pull out wires that i stuck into the deans (not micro deans) connector.


Deans connectors like the one shown by jdebay are pretty good. It would be pretty easy to solder on a male deans connector to wires from the adapter. That way you don't have to think about polarity again once you solder it up the right way. Not all batteries come with that type of connector however. I say buy the battery you want with whatever connector it uses and then order a male version to match to solder to your adapter.

Another type of battery connector that I like to use is the Traxxas type connector. It's not as compact as the Deans type but it's easier to solder up and has a very solid connection. I usually cut off whatever the battery comes with and add these.

Traxxas connector
@Zap .. Thanks for the info. I previously had thought that LiPos had the "memory effect" and that most of them get ruinrd by not fully discharging them.

I cant remeber where but I saw a post where DJ Sures recomended NiHm batteries in the battery packs of the v3 for alot of the same reasons you listed as benifits of LiPo.

Maybe I misread some of the details but he definatly recommeded HiHm recargables. I remember being very happy reading it because it was the route I was going so I didn't have to keep buying batteries.

I'm not trying to confuse anybody but now I'm a bit confused on this.:(
Lipos and Li-Ion have basically zero battery memory effect and you can damage them by over discharging them... You can however, charge them any time you want.... NiMH have some memory effect, but very little... NiMH can benefit from the occasional deep discharge to regain some lost battery life. They can be charged at any time as well, even if just to top up... NiCad have the most memory effect... NiCads need to be fully discharged every time they are used before recharging....
I could be wrong but DJ may have been referring to using rechargeable AA batteries vs standard alkaline AA if you go that route?
United Kingdom
Thanks for your replies guys. I've just ordered myself a balance charger and decided to go for the 5000 mAh LiPo battery Rich mentioned, which should be with me in a couple of days.

@Richard. Yes it is just the EZ-B and power shell I will be using, but when I mentioned using the barrel jack, I meant the stand alone jack that comes with the dev kit. Thanks for pointing me in the right direction. :)

@jdebay. Thanks for the photo. That's what I had in mind, so thanks for confirming. ;)

@Steve.... sorry, the stand alone barrel jack is what I meant.... You can use it with your 5000mAh lipo no problem......
United Kingdom
No problem. Thanks Richard. :)
@Richard Thanks for clearing that up for me.:)

@Zap Yes I am in fact talking about the AA's;)
Hi everyone

I have just bought this "bad boy" which is a Venom LiPo 2S 7.4V 10,000mAh 35C. I am pretty confident that I can just connect it up to my roli and it will work fine but can anyone confirm this?

User-inserted image

Also can anyone advise of the best setting to charge it? My lipo charger will charge up to 5 amps.

And can I also presume that the low voltage warnings on the EZB will continue to work when a higher rated battery is used?

Thanks for any advice - I would prefer to be on the right track before connecting.


@ZebraStripes Yep... plug and play dude.... With that battery I am pretty sure Roli could drive across the outback on one charge....:P

Your charger should work too. However being a very large capacity battery it will take much longer to charge.... If it were me (and I am not knocking ez robot's lipo charger) I would grab a better lipo charger off of eBay...

Remember amps are "pulled" by a device not "pushed" into it by the battery... What you have effectively done is buy a bigger gas tank for Roli... Roli is still going to draw the same amount of power it did with it's original battery, however now with the larger capacity battery it will have a much longer runtime...
Thanks once again Richard for your very helpful response. Happily I have a good lipo charger and so should be able to shorten the charge time. Sending roli out into the outback is a great plan but I will need to extend my wifi range by just a little ...


Can anyone tell me if it is safe to leave the lipo battery plugged into the ezrobots when they are turned off and not being used? I was reading that lipo batteries should not be left plugged into devices and sit unused. I read that you should unplug batteries when not in use and kept in a fireproof container. Are they really that unstable? Can they stay safely connected to the ez robots in the off position and checked periodically to make sure they aren't drained? Or should they batteries always be removed from the ez robots when not in use?
Also, can anyone tell me where I can a battery replacement for the ez robots here in the United States? I see them all over the Internet but can't seem to find the dimensions that will fit the ez robots. Everything I come across is just too big to fit.
They shouldn't be left plugged into the charger but are okay to leave inside the ez-robots. The way these burn up are if they get punctured or if they get gassy. The shell helps prevent them from getting punctured. They should be checked periodically to see if they are puffy. Following the instructions for charging will prevent them from getting puffy for a long time. Store them charged and they will keep the charge for many months. I would avoid storing them drained.

I would pickup the batteried from the EZ-Robot store. I don't stock them, but i do buy them from EZ-Robot.
Hey thanks for the info. That helps a great deal