soldissimo
1 µW
- Joined
- Dec 31, 2020
- Messages
- 3
Hi. this forum has has been a very helpful resource in building my ebike recently. Had prev experience with 500w hub motor on SLA batts years ago which was functional but now I'm using an eBay 1000w generic 48v front hub, put on one of my road bikes recently. 10ah lithium iron phosphate in parallel with a premade 13ah 48v bike battery (always same voltage I connect and disconnect separately to check). Have a cheap amazon watt, v, and peak w meter on it. Kit came with a 1250w peak controller without the option for regen, I swapped it to a 1750w peak trap controller with regen and wired that to a button to use separately to the physical brakes (mainly to reduce wear on pads rather than recover energy). I'm very happy with it, ,but considering an alteration/potential improvement inspired by this site- so registered to ask.
It accelerates up to 30-31mph and the motors rpm/v and back emf limit me there because my battery is at ~50v. I read with interest a thread about the hill climbing boost controller one of your members was running on a 36v pack. I want to use a similar 1800w boost converter set to 90v to give me 22amps 90v instead of 35a 50v I am getting now. My understanding is if I have relays activated by a push button that would switch the controller input to the higher voltage current limited supply I would be able to get a few mph more----Is this right? I already have a 12v system supplied by a 120w step down and many heavy duty auto relays I can use. Also my main question is what about on releasing the button, the sudden back emf would give me a sharp braking effect but would there be any harm to my batteries (or controller?) from suddenly having a higher voltage connected in its circuit, or would the relatively small size of that back current mean its not an issue? I don't want an early death to the batteries (or thermal runaway lithium flame up near me).
It accelerates up to 30-31mph and the motors rpm/v and back emf limit me there because my battery is at ~50v. I read with interest a thread about the hill climbing boost controller one of your members was running on a 36v pack. I want to use a similar 1800w boost converter set to 90v to give me 22amps 90v instead of 35a 50v I am getting now. My understanding is if I have relays activated by a push button that would switch the controller input to the higher voltage current limited supply I would be able to get a few mph more----Is this right? I already have a 12v system supplied by a 120w step down and many heavy duty auto relays I can use. Also my main question is what about on releasing the button, the sudden back emf would give me a sharp braking effect but would there be any harm to my batteries (or controller?) from suddenly having a higher voltage connected in its circuit, or would the relatively small size of that back current mean its not an issue? I don't want an early death to the batteries (or thermal runaway lithium flame up near me).