GNG 1000W battery options

speedmd

10 MW
Joined
Nov 14, 2012
Messages
3,335
Location
new england
Looking for around a 20AH pack for the GNG450 watt kit I just got and having trouble deciding on the 6s lipo 5000mah bricks that may be best for me long term. I am planning upgrades to the kit and will be most likely pushing things a bit as the years roll on. I have decided to go with a LIPO pack 12s 4p. Choices now are to go with zippy flight max 25c, 30c or 40c packs. 8x 25c is aprox $352, and the 8x 40c are running $475. I would like to keep cost down but what I giving up when thinking of possibly re using the bricks in other builds to 18s3p or 24s2p. Any advise / help is welcome.
 
i have 4 zippys x 5000mah 15c and 2x 8000mah 30c zippys.
the 15c work great, no different in power delivery to the 8000mah ones.
the c ratings on the batterys are hyped up, deduct a 3rd from claimed c rating.
even at 10 c the 5000mah are capable of constant 50 amp discharge .
they are going to have a easy life on a bike compared with r/c aeroplanes where they come down hot.
id go with the 8000s,only because its less batterys to charge.
richard
 
speedmd said:
Looking for around a 20AH pack for the GNG450 watt kit I just got and having trouble deciding on the 6s lipo 5000mah bricks that may be best for me long term. I am planning upgrades to the kit and will be most likely pushing things a bit as the years roll on. I have decided to go with a LIPO pack 12s 4p. Choices now are to go with zippy flight max 25c, 30c or 40c packs. 8x 25c is aprox $352, and the 8x 40c are running $475. I would like to keep cost down but what I giving up when thinking of possibly re using the bricks in other builds to 18s3p or 24s2p. Any advise / help is welcome.
"best for me long term"
Nothing beats the cost in long term than a123. Could an ebike really use that kind of C rating? I am sure a123 could also satisfy excessive C ratings as well. My advice, go for a123 : ). The cheapest option is the most expensive upfront. There is also the fun fact of a123 packs never exploding no matter what.
If this were for some sort of rc heli or plane, maybe I'd see the need for intense C ratings. Or are you going to be doing some sort of racing?
 
a123 packs never exploding no matter what....
.. Or are you going to be doing some sort of racing?

Thanks for the input. I do like the general idea of the safe batteries. Weight and cost is not close, is it? I can not baby sit the Lipo while charging and not sure what folks mean when they say "never turn your back on them". No racing.
 
richard purchon said:
i have 4 zippys x 5000mah 15c and 2x 8000mah 30c zippys.
the 15c work great, no different in power delivery to the 8000mah ones.
the c ratings on the batterys are hyped up, deduct a 3rd from claimed c rating.
even at 10 c the 5000mah are capable of constant 50 amp discharge .
they are going to have a easy life on a bike compared with r/c aeroplanes where they come down hot.
id go with the 8000s,only because its less batterys to charge.
richard
Thanks Richard
Had not considered the 8000 mah. 16ah for a 12sx2p or even 24ah for a 3p pack. Need to do a bit a more work and make sure what will fit.
 
I am not very familiar with the cost of lipo batteries. The initial cost of lipo is lower than a123. However, lets look at the long term as one may.

https://skydrive.live.com/?cid=92088474ccb8cd05&id=92088474CCB8CD05!1730&authkey=!AJSyZwC_h7piGtY Look at the chart labeled 'cycle life'. After 3000 (three thousand) cycles of 100% DoD (depth of discharge) you will still have 90% of the batteries original capacity. Lifepo4 is often touted for it's excellent capacity and value. Most lifepo4 packs are claimed to reach around 80% capacity after 1000 cycles. I am guessing that after 6000 cycles, a123 will reach 80% capacity.

If you look at it from a value perspective, that is an intense value over the long term. A lipo pack is claimed to reach 90% capacity after 200-300 cycles. Likely 80% after 600 cycles. The way I see it, we can say the difference is cycle life is a factor of 10. If lipo costs 10 times less than a123, then there could be reason to go back and forth. I am pretty sure a123 packs may cost twice as much as a lipo pack. There are various things to consider like size and weight, but I've been shopping around for batteries for a while and a123 seems like a piercing and incredible value. Sadly, there aren't many sources of these batteries. Victpower, osn, em3ev

If you aren't doing any sort of racing or something, you'd likely never even come close to the packs C rating. C rating seems like a concern for many, and it isn't something to ignore with some lifepo4 in some cases, but a123 has a more than acceptable c rating when it comes with ebikes, even if you were to be doing some intense accelerating.

There are plenty of variables within this concept, but I feel confident in saying that most would agree, a123 will last at least 6 times longer than lipo. If you find the cost of an a123 pack to be less than 6 times more, than it's surely something worth considering. I'd also be confident to say that a123 packs are less than 6 times more expensive.

If space is something to consider, a rear rack may be an option.
 
Thanks bowlofsalad

Originally looked at a 15AH flat pack cell battery that was 16s2p listed on ebay. It was made with the smaller flat cells. Price and size is acceptable. Roughly 30% heavier, but workable. Have not considered the other cell types. The ready made pack may be a good starting point while I work out the mechanical mods on the build.
 
Back
Top