Long range/shorter charge time pack

I’ve got 85 Samsung 50s cells ready for a new build. My intent is to take advantage of my city’s large and increasing network of bike/walking paths for long day 75-100 mile trips on a Vanguard type setup primarily using urethane and on the occasion, tubeless pneumies. I’m a big guy around 250 pounds/115 kilos… Should I build a 12s7p, 14s6p, or 16s5p with the cells? I’ve been leaning towards the the 16s5p. I know I’m going to need to charge at least once during these day trips and the higher voltage, lower amp hour pack will be faster to charge from ~30-80% than the other configurations. Am I thinking about this correctly?

3 Likes

From what I’ve seen, higher voltage chargers are bigger so any size you’d be saving from having a less Ah battery would be cancelled out by having the higher voltage.

2 Likes

I think he just wanted to go with less Ah so that way it would take less time to charge.

I think it might be a good idea to look up fast chargers for each of the options and see what they look like size wise and to see the max output current on them. I could see there being more options for the 12s pack charger wise than there are for the 16s pack. If there are no high amp chargers readily available for the 16s5p battery than it might take longer to charge than the 12s or 14s packs

I’d recommend getting a slower charger to use at home to help prolong the battery’s life span regardless of which battery you go with.

2 Likes

Well my logic behind my statement was that you can always just buy a bigger charger so there’s very little need to have a different battery size. And the chargers will be the same size per power output so it’s just easier to not build a different battery.

2 Likes

I actually have three 16s chargers. A 5a, and two 10a chargers where one is actually very compact… So another 16s battery would save me a little money, but I’m going to try to block that out from my decision.

I’m really looking for fast charging at 10a, so I can pump 50% range in during a couple of short stops or single stop of one hour. That said, a 16s5p of the 50s is going to be 20ah and 1440wh, but a 14s6p is 25ah and 1512wh… That’s a difference of 72wh, but that’s probably only about 3 miles on larger urethane for me. I guess I’m wondering if being able to charge 50% of 20ah in one hour versus 40% of a 25ah battery when charging at 10a during an charging break. That 10% more range during a recharge seems to be worth the loss of 3 miles of total range (72wh difference).

Here’s the thing, I think I understand the math of all this enough to be dangerous, so am I over simplifying things?

I don’t know enough about high voltage builds to help any further. I just was suggesting the first thing I’d look into to decide since if you couldn’t buy a high amp charger at the right voltage than it wouldn’t fit what you wanted.

@Shadowfax or @Skyart might be able to help you more since they both know more than I do

Other people on here should be able to help as well but I’m trash at names and remembering who has done what

in a way you are correct about the pack charging “faster” on 16s vs 12S assuming the charger you use for each repective pack is the same A output.

however you have to remember about W output.
if i have my math right, a 4A 12S charger will charge your pack in the same time as a 3A 16S charger. so a 16S charger doesn’t necessarily need the same A output to have the same W output as 12S. something to keep in mind

choose your pack specs on how you ride, speed expectations, etc

and choose your charger based on W output to keep your charge tines down (though fast charging every cycle will lower your pack health much quicker than slow charging most of the time and fast charging once in a while

2 Likes

A portable charger that is a reasonable size will frequently have the same rated watts for charging, regardless of voltage.

Example, @Skyart chargers:

12s charger - charges at 12amps (604w)

18s charger - charges at 8amps (604w)

So, you’re not charging any faster going high voltage.

The real reason you should go 16s is because you’re 250lbs. You’ll be less likely to overheat motors on 16s vs 12s, because at the same watts delivered, you’ll be pushing fewer amps.

If you go high amps and high voltage… well, now you’re talking my language. My new build charges ~1000w

2 Likes

And to add to that 16s must be coupled with lower KV motors if you are looking for inprovements in heat

2 Likes

Your 16S chargers are 672W, that’s already very high. You could achieve this and a bit more on 12S too but it’ll also be really big, probably bigger than what you already have. Pictures for size comparison of two from the same manufacturer below


The bigger 12S charger there is more powerful (756W), but if you stepped up to that size enclosure then a 16S charger would be slightly more powerful again (804W). The point is though, you can get bigger faster chargers in lots of voltages, but you already have two that are powerful, and it looks like in general the higher voltage ones are either a little bit smaller or a bit more powerful because lower current means less heat. So IMO probably go with the 16S but it’s not a disaster to go with any of those voltages if you’re ok buying more high power chargers, as Evan said they are pretty comparable power for the same size

1 Like

Sorry… im probably missing something here… wont more P groups be better for OP than more in S?

12s9p gets me about 80-90km depending on gearing, coupled with a fast charger could achieve what OP is looking for without the need for high voltage?

Probably being thick… moving along

1 Like

Yeah it could definitely get more range that way, but at 9p of 50S cells you’d need a 22.5A charger to go from 30-80% in an hour. If you reconfigured it so (roughly) the same number of cells were running at 4 or 5p you’d only need about a 12A charger. High current chargers are clunky. Though tbh so are high voltage chargers, as we mentioned total power draw isn’t a huge difference, the main issue to me is that replacing OPs 10A 16S chargers with equivalent 12S ones would be a pain in the ass and either no smaller or a bit bigger

1 Like

more cells = more capacity
12s7p or 14s6p are the ideal versus the 16s5p for that reason, but it’s about a 5% capacity difference, which could be made up for by potential efficiency improvements of a higher voltage setup if you gear appropriately.

As for the charger argument, my understanding is that chargers are built for a set wattage, meaning for the same amount of energy in, the chargers for the various voltages are about the same. If anything, you need a smaller chargeport on the higher voltage pack since you’ll have less current going through it.

I’d do the 14s6p with a 16s capable esc. The extra voltage headroom should in theory lead to better reliability as running components below their maximum rated voltage typically does well for lifespan

2 Likes

Just swapped out my old bioboard motors for your new 151kv, 6495s… Love them, but it’s a different build.

I’d like to run your 190kv 6355 motors on this new build, but do you think 14s would be too much? It’s really supposed to be a touring, urethane build to cruise on, not a race board… If I keep the battery/phase to less than 50a and 65A/side , and get my gearing around 3:1 for ~110sh urethane would I get any noticeable gain in efficiency running 14s6p vs 16s5p?

12s really isn’t an option here since I’d have to use a huge 15a charger and I don’t want to lug one of those around.

You posted the exact 16s 10a charger I use for long group rides… It’s the smallest charger for anywhere near the amount of watts that I’ve come across on Ali… I’m pretty sure they have 12s and 14s 10a chargers with the same form factor, but as soon as they go over 10A then the charger also gets bigger like you mentioned…

Unless I decide to go with Skyart’s new 6355s at 14s, I’ll probably go 16s. The 5% in total wh can be gained back in “faster” 10a charging of the smaller pack.

1 Like

14s will be just fine

1 Like

Hahahaha, it’s a small world of chinese electronics

1 Like

if money is no object, go 24s and get this charger HUAWEI Charger R4830G1 – Hou Nin' EUC Club