Help! How much will i gain by goinv 48v
- Thread starter steverebo
- Start date
If you have a MXUS 3005 or 3006 you can run the Grin motor simulator to see how it will perform under different conditions.
ebikes.ca
Motor Simulator - Tools
Our ebike motor simulator allows you to easily simulate the different performance characteristics of different ebike setups - with a wide selection of hub motors modeled, and the ability to add custom batteries and controllers and set a wide variety of vehicle parameters you'll be able to see...
It's pretty simple. You gain 30% of everything - power, torque and speed. The speed you gain is the maximum turning speed of the motor. Your actual max speed on the road depends on many factors, like overall power, wind resistance, slope, etc.
An unusual approach, but as far as the motor and controller are concerned I can't see any complete 'no go' red flags. The display may be an issue, it needs to be happy with the supply voltage, and the battery capacity indicator will be wrongly calibrated.
As long as the maximum current is OK for the LiFePO4 battery, and you don't run the main battery flat, it will just look like a higher voltage battery to the controller and motor. If you flatten the LiFePO4, you would be able to revert to 36V to get home.
Would I do it myself? Maybe as an experiment, but for daily use, I'd buy a 48 V battery for a simpler life!
As long as the maximum current is OK for the LiFePO4 battery, and you don't run the main battery flat, it will just look like a higher voltage battery to the controller and motor. If you flatten the LiFePO4, you would be able to revert to 36V to get home.
Would I do it myself? Maybe as an experiment, but for daily use, I'd buy a 48 V battery for a simpler life!
M
I'm looking for a cheaper solution to bumping my voltage from 36v to 48v as all the replacement batteries I've found are in the 250 - 300 range whereas the booster battery idea is relatively cheap.
Is there any guides on doing this around?
My controller and lcd have 24v 36v and 48v options so they can handle the voltage.
I'm looking for a cheaper solution to bumping my voltage from 36v to 48v as all the replacement batteries I've found are in the 250 - 300 range whereas the booster battery idea is relatively cheap.
Is there any guides on doing this around?
- The booster battery needs to be able to supply the current that the controller demands.
- It must have it's own BMS with its own low voltage cut-off.
- It should have its own voltmeter so that you can see its state of charge. The same applies to the 36v battery.
- The controller might need to be reset by discharging its capacitor to change from 36v to 48v.
I hope adding a LiFePO4 8ah 12v battery, to an existing 36V setup, is not seen by eBike users in general as a low cost way of adding more power and speed.
People have been doing it for years. Most bikes are limited to 44v by the controller, so a 2S pack of 18650s is what you need. 36v/48v controllers can handle a 3S booster pack and probably a one 4S too. You'd have to check the capacitors to confirm. You can use R/C lipos as well, which can give good power from a small and cheap pack, but you need to know about safe handling and control of lipos if you want to use them.
KirstinS was quite a prolific forum member, who posted a lot of details about his adventures with booster packs. He had some problems with his account, so now posts under another name, which I can't remember. It's a shame because he has a lot of info about it. IIRC, he had a few problems too.
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Kirsten rarely posts now but uses the new monika of Titanium alex.
For a booster one needs to use the same battery chem so the discharge pattern is similar, as with paralleling when one places the two packs in series the single cell voltages need to be much the same other wise lvc will be an issue ( their is no issue with current heat transfer as in paralelling) .
Ideally cells of the same mah and current rating need to be similar but could be a different cell brand.
If the 36v battery is 5p then the booster will need to be 3s 5p, to prevent issues one needs to keep discharge and cell ratings as similar as possible.
I use to run 12v Sam 26F booster packs in series with my Panny PF packs and had no issues , voltage discharge pretty much followed linearly . One needs to keep an eye on the booster pack voltage just for safety even though the BMS LVC will or should prevent failure.
My PF's were 14.5ah so I made my 26F's 3s 6p for 15.6ah as 5p would have been a bit low at 13ah.
Some 4 or 5 years on I don't use boosters no more but the pair of 15.6ah 3s packs are still in use as portable 12v power packs for other equipment I use for my beekeeping.
For a booster one needs to use the same battery chem so the discharge pattern is similar, as with paralleling when one places the two packs in series the single cell voltages need to be much the same other wise lvc will be an issue ( their is no issue with current heat transfer as in paralelling) .
Ideally cells of the same mah and current rating need to be similar but could be a different cell brand.
If the 36v battery is 5p then the booster will need to be 3s 5p, to prevent issues one needs to keep discharge and cell ratings as similar as possible.
I use to run 12v Sam 26F booster packs in series with my Panny PF packs and had no issues , voltage discharge pretty much followed linearly . One needs to keep an eye on the booster pack voltage just for safety even though the BMS LVC will or should prevent failure.
My PF's were 14.5ah so I made my 26F's 3s 6p for 15.6ah as 5p would have been a bit low at 13ah.
Some 4 or 5 years on I don't use boosters no more but the pair of 15.6ah 3s packs are still in use as portable 12v power packs for other equipment I use for my beekeeping.
I haven't looked for a guide, which doesn't mean there isn't one, but all you are proposing is to connect two batteries in series. Experiments don't get much simpler than that.
If you are not confident that you understand what's going on, then my advice is always don't do it.
The gain will only be noticed if one wants speed and a bit more torque if on a hilly route. Usally range will be increased but that is of no significance on such a short run.
I would agree with that sentiment.
There is a belief, in this age of the the Internet and YouTube, that any task can be reduced to a simple turorial or follow along video.
I think it's called learning to do stuff. Gardening is dangerous if you don't do it right. Riding a bike on the road is a lot more dangerous than gardening, and I would say that messing about with electrical stuff is less dangerous than riding a bike on the road.
I bet that if you asked every forum member whether they ever got hurt enough to go to hospital from riding their bike and whether they got hurt by messing about with electric bike stuff, the ratio will be more than 100 bike riders to one messing with electrics.
You guys need to get things in proportion.
Its advised not to charge eBike batteries when you (or someone else) is not awake and able to supervise the charge.
https://www.london-fire.gov.uk/safety/lithium-batteries/charging-electric-bike-and-electric-scooter-lithium-batteries/
"Never leave your battery to charge when you are out or whilst you sleep"
I am guessing this advice is given based on quite a few assumptions.
I would argue charging battery unattended and at night might be much safer than supervised charge.
For example when you charge battery outside house and set specific time for charging.
Batteries don't need charging every night if the usage is light ( short distance) and depends on the battery ah .
My 44v 6ah battery I can get aprox. 20 - 30 miles dependant on the weather , headwinds and time of year, etc, etc , often if only using it locally I will only charge it once a week.
My 44v 6ah battery I can get aprox. 20 - 30 miles dependant on the weather , headwinds and time of year, etc, etc , often if only using it locally I will only charge it once a week.
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