Running 48v parallel with 52v???

[Tim Goffin]

So any one know if this would be a bad idea....I have a 17ah52v and a 21ah48v

 

[peter.c]

no do not do it serious damage will occur

 

[Tim Goffin]

Ok...I can just carry both and just plug the other in when other has gone low....I have such a bad case of range anxiety it's unreal...I'm going to stay local and run my battery till it cuts off this weekend so I have a rough guide...

 

[peter.c]

are you going to run full power all the time flat out or do you want to never pedal or more than 25 miles at high power levels if yes take the spare battery if no then you should not need it unless you are hill climbing

 

[Tim Goffin]

I hardly use throttle and stay in pas 2 most of time....pas3 on steep hills...dunno why I bought such a powerful kit...looking into more economical kits now

 

[peter.c]

Your b-m will go numb before you run out of battery unless you have drastically adjusted the settings with a laptop what display do you have does it show battery volts

 

[Tim Goffin]

Yes kt-lcd3

 

[Tim Goffin]

Your b-m will go numb before you run out of battery unless you have drastically adjusted the settings with a laptop what display do you have does it show battery volts

I wear padding ;-) ,,,, I used to cycle non ebikes everyday... bum don't get to sore lol

 

[peter.c]

if you do 10 miles how how much does the voltage drop if you do 20 miles

if the 48 v starts at 51 ish how quick does it drop sorry I cannot remember is it a 48v ga cell battery from jimmy you use if so does the batt light on the battery even go down if so how many led go out my insat battery goes a lot further than the Chinese junk it replaced

 

[Nealh]

Hello Tim,
Yes as P.C has said they need to be same voltage rating to parallel other wise you will almost certainly damage the 13s bms and possibly the controller, the power surge by way of amps/heat flow will be bad news and could even melt the wiring.

When/ if you get a smaller hub 350/500w you will have 1900 wh's good for at least 200miles range, I would say.

For the 48v battery 41.6v = 3.2v per cell though not really worth draining much lower, if you go to 40v you are looking at DOD of 3.07v.
For the 52v one 44.8v = 3.2v per cell, 43v = 3.07v.

Easier to simply voltages and stick to max DOD of 42v & 45 respectively.

 

[Tim Goffin]

if you do 10 miles how how much does the voltage drop if you do 20 miles

if the 48 v starts at 51 ish how quick does it drop sorry I cannot remember is it a 48v ga cell battery from jimmy you use if so does the batt light on the battery even go down if so how many led go out my insat battery goes a lot further than the Chinese junk it replaced

My batterys are from insat....very impressed with them...Jimmy knows his stuff that's for sure

 

[Tim Goffin]

Hello Tim,
Yes as P.C has said they need to be same voltage rating to parallel other wise you will almost certainly damage the 13s bms and possibly the controller, the power surge by way of amps/heat flow will be bad news and could even melt the wiring.

When/ if you get a smaller hub 350/500w you will have 1900 wh's good for at least 200miles range, I would say.

For the 48v battery 41.6v = 3.2v per cell though not really worth draining much lower, if you go to 40v you are looking at DOD of 3.07v.
For the 52v one 44.8v = 3.2v per cell, 43v = 3.07v.

Easier to simply voltages and stick to max DOD of 42v & 45 respectively.

200miles!!! I could cycle from west sussex to norfolk on a single charge haha....still looking for a good 250w/500w motor for my new build...

 

[Tim Goffin]

if you do 10 miles how how much does the voltage drop if you do 20 miles

if the 48 v starts at 51 ish how quick does it drop sorry I cannot remember is it a 48v ga cell battery from jimmy you use if so does the batt light on the battery even go down if so how many led go out my insat battery goes a lot further than the Chinese junk it replaced

Just done 11miles and voltage went from 57v (Not fully charged) to 53.5v pas3 pulling 350-500w most of time...

 

[Nealh]

Just done 11miles and voltage went from 57v (Not fully charged) to 53.5v pas3 pulling 350-500w most of time...

Doesn't surprise me, with a 250/500w geared hub and a 17 or 20a controller pas 3 you would see about 170 - 240w.so range would be better.

 

[peter.c]

OUCH that's a current hungry motor the range might be limited but 25 should be possible still

 

[Tim Goffin]

1500w at 35a, and I stupidly done shunt mod haha....it pulls like a train tho...

 

[Tim Goffin]

Doesn't surprise me, with a 250/500w geared hub and a 17 or 20a controller pas 3 you would see about 170 - 240w.so range would be better.

Indeed...think I'm going to go for the 350w from Germany u mentioned....then kt controller....

 

[peter.c]

You might have mentioned the 1500 watt mod first is it a police q bike used for pursuit does the controller get warm enough for toast

 

[Tim Goffin]

LoL...I bought a 1500w kit from eBay thinking if I bought enough battery it would be fine...I've learnt the expensive way I suppose....I might ad my.car only does 16mpg haha...maybe I'm just a idiot...

 

[Tim Goffin]

You might have mentioned the 1500 watt mod first is it a police q bike used for pursuit does the controller get warm enough for toast

Also the controller never even gets near warm even if I'm gunning it for some time