Equivalent Lipo replacement for 60v 15Ah Ping

[Speedfreke]

Hello, My 60V 15Ah Ping is reaching the end of it's life and I definitely want to go LIPO. However I'm not sure what an equivalent replacement would look like. I'm getting a range of approxomately 18 miles on the Ping and would like to extend that a bit.
Also I would like to get as compact a pack as I can and one with fewer cells to make it less complicated. I'm fully aware of the dangers and precautions involved with Lipo and don't intend to ever take the battery into the house. Can anyone offer some specific proposals for quality Lipo's and charger especially from experienced Lipo users?

 

[Ykick]

15S3P RC Lipo composed of 5Ah bricks will operate between 57-62V, 13-14Ah real world, 62V doesn't harm most 48V systems and probably much less sag than what you're using. I build 15S1P using 3qty 5S bricks in series then parallel those groups for capacity. But you can use other brick configurations to reach 15S. Depending on your controller you might also want to consider 18S?

What is 60V Ping voltage hot off the charger?

 

[cwah]

How come your ping is already in end of life? I thought Lifepo4 has a much better lifespan?

For how long did you have your pack? and how many cycles have you put on it? Do you still have 80% of its initial capacity?

 

[dogman dan]

What's your chargers voltage? 70v or so? divide that number by 4.2 to get equivilant RC lipo voltage.

If your controller can take it, ( 72v controller?) then 18s is a handy number for lipo. Three sets of 6s packs. 63v nominal, 75v full charged.

Figure that out of a 5 ah pack of lipo, only about 4.5 ah is really avaliable for use, so as to avoid accidental overdischarge. When they talk about 5 ah, they mean going to 3v, and you don't want to do that. Stop at about 3.65v per cell. As it ages, capacity will drop another .5 ah or so per pack.

 

[dogman dan]

Re reading a thread, he seems to have repeated bms issues. He never replied when I asked if he rode with the bms smothered in a bag overheating them.

20 amp controller supposedly, a ping should have lasted him 3-4 years at least.

Sorry if I rubbed you the wrong way, but if pings have an issue we need to know what it is.

 

[Speedfreke]

The only heat generated on my set-up was mild to say the least and that was on the controller and on the 406 hub running continuously at full speed , The split battery pack and the BMS were cool to the touch. I' ve read that loose connections (those damned andersons) especially in split packs can cause lites on bms to stay on. I've seen pics on this sit and it is always the centre lite that has this problem. I.ve replaced one cell corresponding to the lited led and got the battery to work again however the lite still stays on and the two adjacent cells continuosly report lower voltages as well. I've 0rdered a new bms and will need a few more cells to revive the battery however I shudder to install them. But I think the battery will at least be usable. The new lipo I'm looking into will be for a new similar build or to use as a back up if I have more problems with the ping.

 

[Speedfreke]

Sorry Dogman I don't understand the tech talk but the charger is 75v. 75 divided be 4.2 equals 17. Now what? Do you mean a 17s pack? I do want a little more distance on the new battery but the 75v lipo you recommend is the same as I have now and should get me the same speed.

 

[Speedfreke]

I have a 20 amp controller which works well . my new build will be with my old 408 hub which used to run on 72v lead acid. I get good performance and little heat from my present 60v 15Ah ping with the 406 hub and figured that a good lipo pack will maintain the speed and get longer range.
Ykick, The battery is 75v fresh off the charger. do you think the lower voltage you're recommending will maintain the same speed as my 60V ping? Also all those batteriies sound like an expensive charger or 2 is neccessary?

 

[Speedfreke]

cwah, I don't know the present capacity of the ping , never measured it (don't know how) but will know after I replace the bms and read up about it . I believe the battery is good but the bms is the problem. I did replace one swollen cell at the end of the split pack but that could have been caused by a loose anderson which joins the 2 packs causing an led lite to stay on permanently until I separate the 2 packs.. I also think the adjacent 2 cells don't charge up to snuff but will know better next week when the new bms arrives.

 

[DAND214]

I did replace one swollen cell at the end of the split pack but that could have been caused by a loose anderson which joins the 2 packs causing an led lite to stay on permanently until I separate the 2 packs

How woul the anderson cause the led to stay lit. I've had a couple leds stay lit and they only had andersons on the charge and output leads. so how does that cause the problem?

Dan

 

[wesnewell]

A 60V ping is probably a 20s pack with a nominal voltage of about 63V. The best rc lipo equivalent would be an 18s pack with a nominal voltage of 66.6V and fully charged to 75.6V. You'd need 9 of these wired 18s3p for an equivalent pack.
http://www.hobbyking.com/hobbyking/store/__9176__Turnigy_5000mAh_6S_20C_Lipo_Pack.html
Of course with rc lipo there are lots of options depending on your needs and the controller you have. Without knowing the specs of your controller it's hard to say what would work.

 

[Speedfreke]

From reading search results, i found others had the same problem with andersons (or any other connector which disconnects). Apparently if the connector is not pushed all the way in arcing occurrs and it is this arcing that burns out the capacitor corresponding to that particular cell. In my case the bike stopped all of a sudden. When I checked the connections the wire joining the split pack was very loose. When I reconnected it the , the bike was working again but an led was on and stayed on all the time unless I disconnect that wire again.

 

[Ykick]

Any power connection is a genuine point of concern and often root of many evils. In a perfect world, fewer connectors the better but some connections remain unavoidable. However, careful construction, proper rating and use can make for very reliable connections.

 

[Speedfreke]

So 20s lipo is the 60v ping equivalent but 18s is more convenient? I need more range than what I'm getting with my ping, maybe 12 of those packs would fit the bill. Would that be 3s4p? that is lots of batteries. Would it make charging more difficult and expensive?
I don't have a charger yet, I intend to buy everything I need all at once when I'm comfortable with my choice.
Are there larger (in voltage and amperage) single lipo cells available ?

 

[wesnewell]

So 20s lipo is the 60v ping equivalent but 18s is more convenient?

No. 20s lipo is 74V (20x3.7). I assume Ping 60V batteries are 20s of lifepo4 (20x3.2=64V), but they could be 19s. Don't know and can't find cell count on his site. 18s lipo (66.6V) would be what you'd want to use as an equivalent to a 60V ping. If your controller will support higher voltages, you can of course run higher voltage packs. I run 24s lipo (88.8V) on mine.

 

[Speedfreke]

According to dogman , Isn't 20s lipo actually 4.2 x 20 = 84v? That is probably too high for my 20amp 72v controller.
I think 18s is what I need if there is such an animal.
Does anybody know if larger lipo cells are available both in voltage and amperage? I personally don't like using tons of batteries.
Does lipo come in pouches which would make the pack more compact?
I know I can research this but I would love to hear from people who have had direct experience with different types and combinations.

 

[wesnewell]

20s lipo is 84V fully charged, but it's 74V nominal, as I just posted in my last post. You can use 18s if you want. It's actually a 66.6V nominal pack that will fully charge to 75.6V. if you have a 72V controller, either will work unless it's really not a 72V controller and only labeled as such.

 

[Speedfreke]

thank wesnsell and dogman for the advise, however ping sent me a 72v instead ofthe required 60v bms threrfor the deteming the health of the batterywill be put on hold until new newboard arrives. pain in the neck,