Battery upgrade for Cycloctricty Stealth 1000w

[Andy Bluenoes]

I was hoping if someone could advise on this as a possible upgrade for the current 48v 12ah battery on my stealth?

http://www.eclipsebikes.com/whale-175ah-lithium-frame-battery-sanyo-cells-p-1129.html

I can just about get to work which is around 15 miles on the current battery using my preferred power and assistance settings.

I'm likely to be moving around 3 miles further from work, using pretty much the same route in. Unless I knock my power assistance levels down a fair bit, I don't think it will make that extra mileage.

So, I was wondering by how much I should expect this battery to take me....assuming it fits of course!

 

[Deleted member 4366]

I'll think you'll find it a lot better. Your last battery was probably on the edge of its capability, while as that Eclipse one would be cruising.

It's very heavy for a bottle fixing. I'd add at least one more rivnut to your frame. Something like 4 in total would be good.

 

[Andy Bluenoes]

Thanks d8veh, Ill put it on my wish list, i'm doing 120 miles a week so another factor i need to take into account with the current one is battery degradation I guess.

 

[RobH]

Could a second battery simply be wired into the first one to give double the capacity?

 

[Deleted member 4366]

Could a second battery simply be wired into the first one to give double the capacity?

Yes, but it's complicated. They have to be at the same voltage when you connect them and they have to be disconnected when you charge them.

If you could find or build a second battery that has a BMS where the charge and discharge wires go to the same pad, i.e. not separate charge and discharge mosfets, you can leave them permanently connected and charge both of them through the charge socket on your original battery.

 

[RobH]

OK thankyou. Just so I'm clear....if they were both fully charged when they were connected and they were re-charged separately then this should work.
Is that correct?

Has anyone tried this?

 

[craiggor]

Yes, I do this with a pair of lawn mower batteries.d8veh gave me the same advise as above on the small battery bargain thread. My batteries where bought new and have always been used as a pair,except when I used them once each to see how they performed singly.If you do this with a used battery and a new one I think the used one will drag the new one down a bit capacity wise.ie amp hours.

Sent from my D101 using Tapatalk

 

[RobH]

I suppose another way would be to have the two batteries separated by a switch and then when one was exhausted you could switch to the other.

 

[anotherkiwi]

I suppose another way would be to have the two batteries separated by a switch and then when one was exhausted you could switch to the other.

I thought about that for quite a while and came to the conclusion that it was just as easy to swap batteries. The advantage of having the batteries in parallel is less sag on the hills.

 

[Deleted member 4366]

It doesn't matter if new or old or different types. The only thing that counts is voltage. I supposed if one was completely knackered, like self-discharging, you shouldn't do it.

 

[Andy Bluenoes]

All sounds very complicated,,,I think for me it would be easier to put the spare battery in my backpack and swap them over if needed, although its not the lightest battery in the world !

 

[Woosh]

Has someone suggested getting a second charger? Think about topping up the battery at work?

 

[Andy Bluenoes]

I have to recharge my battery when i get to work ready for the return leg, so take the charger with me. Touch wood, Ive not managed to leave it at home yet

 

[Woosh]

what kind of speed you ride at to flatten a 48V 12AH in 15 miles?

 

[Andy Bluenoes]

Variable speed really, along the off road paths probably around 19 to 20, on the road stretches, around 17. All depends on the wind and the weather. I have studded tyres on at the moment too, which dont help the cause either I guess.
I do put a fair amount of effort into it too, but not so much on the way to work that im dripping with sweat, I save that for the return leg.

Ive done 900 miles on it so far, dont know if the range is decreasing already

 

[RobF]

what kind of speed you ride at to flatten a 48V 12AH in 15 miles?

Power consumption seems very high to me.

I wonder if the battery is holding anything like 12ah.

It's unlikely to have lost capacity already, so the quoted figure may be ambitious, or the pack has been faulty from day one.

 

[Andy Bluenoes]

Is there a way I can check that with a standard multimeter? I have one, but dont really know how to use it, apart from to test for voltage

 

[RobF]

You might like to take a look at the Bosch range cockpit which will give you an idea of how speed kills range.

Pick the Performance Line Speed motor, turbo assist, and the 400 battery - nearest to yours - and have a tinker.

https://www.bosch-ebike.com/en/service/range-cockpit/

 

[Andy Bluenoes]

That gives some interesting results, thanks Rob. I would say im not getting quite what i should be from the battery after playing around with it a bit

 

[Woosh]

Is there a way I can check that with a standard multimeter? I have one, but dont really know how to use it, apart from to test for voltage

Yes, simply measure the battery's voltage before you set off then again when you arrive at work. Post the readings here, we'll help you to make sense of these readings.