Charging ebike battery from a leasure battery?

Waynemarlow

E*POWAH Master
Dec 6, 2019
1,108
888
Bucks
Guys its the battery itself that’s limiting the charge current, you could have the potential of 100 amps at the cables but a lead acid gel leisure battery is simply not going to pull that current. Nowhere does he talk about running anything other than charging the one battery.

Lets put this in the realms of something EBikers can relate to. I stress test any battery I build for my EBikes with a draw off of 650Watts as that’s what most modern EBikes are capable of pulling for short periods of time. Now at 12 volts ( car battery volts ) x 20 amps ( size of maximum current allowed by the inline fuse ) = 240 Watts ( Watts used is the real thing we need to use as that is the Power used ) so the Van set up is using about 1/3 rd of the power of an EBike. Now have a look at the size of the connectors between your bike motor and the battery, they are not very big and nothing like the mains cables going to your fuse board which on older houses were 10mmsq and more modern 16mmsq, which is being suggested that should be used nor the size of the main wire in your car going to the starter motor which is typically a 16mmsq wire, sometimes less.

Where am I going with this, well it just so happens that my battery stress rig is connected with 79 strand speaker wire, yes it’s only one metre long but never the less I’m running 2 1/2 times the load than that on the vans cables. Do my wires get hot, yes after about 30 minutes of constant 650watts they get luke warm to the touch, do they melt, nope that’s one of the advantages of speaker wire, very low resistance wire and huge cooling surface areas.
 

routrax

E*POWAH Master
Jun 15, 2019
382
529
Uxbridge
There's a danger than people will end up thinking a 'this is what you can get away with if you understand the risks' solution and a 'this is how you're supposed to do it' solution are the same thing.

EMBN should not have put that video out a tutorial.
 

philuk

Member
Jun 22, 2021
52
66
North Yorkshire UK
We are in the final stages of a camper conversion so Ill be charging from a 2000Watt inverter with 2x 100ah batteries, with solar and b2b charging to top it up

van.jpg
 

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