Battery Advice required

[Headshok]

Hi all I have been using this for a couple of months now and it works perfectly for what need. but due to the weight of the total rig and although I pedal it and only use the Medium Power setting I am only getting 3 miles range.- I don't use the throttle only pedal assist

I know that this is good for the weight it is pulling but I would like go large on the batteries and I would like to know if I can wire in some wheel chair batteries to get a greater range? and would my existing charger work

It is 36 v and I have 3 small batteries.

What are my options

https://ep1.pinkbike.org/p4pb16864166/p4pb16864166.jpg

 

[sjpt]

Typically electric bikes use lithium batteries, and a 36v nominal one is actually quite a bit above when charged (42v), dropping as charge is taken. The controller typically will cut out to protect the battery if the voltage gets too low. Yours starts at 36v, and drops to maybe 30v (from the spec sheet) for rated capacity. The controller may just be cutting out long before your battery is used up. You could get an idea of that by how long it takes to charge again. Also, I am not sure those batteries expect to deliver continuous amperage needed for an ebike.

 

[wheeliepete]

You can go at large as you want on batteries, space and the extra weight are your limiting factors. Lead acid batteries are not a good choice for electric bikes, esp. as you are running a controller designed to be used with a lithium-ion pack. Expect to use about 50% of their capacity before the voltage drops too low, and the controller cuts power. If you have a 36v Pb charger, then it will charge any pack of 3 x 12v batteries. Obviously, the larger the batteries the longer they will take to charge.

 

[Headshok]

Typically electric bikes use lithium batteries, and a 36v nominal one is actually quite a bit above when charged (42v), dropping as charge is taken. The controller typically will cut out to protect the battery if the voltage gets too low. Yours starts at 36v, and drops to maybe 30v (from the spec sheet) for rated capacity. The controller may just be cutting out long before your battery is used up. You could get an idea of that by how long it takes to charge again. Also, I am not sure those batteries expect to deliver continuous amperage needed for an ebike.

thanks you might be correct as it recharges to full very quickly - less than 2 hours I suspect - but I will monitor it this afternoon to be sure, also I will check the voltage when it thinks it is flat. What I do notice is that the battery @monitor (which is 4 red less for full) goes from 3 lights to flat in about 500 meters.

 

[Headshok]

Typically electric bikes use lithium batteries, and a 36v nominal one is actually quite a bit above when charged (42v), dropping as charge is taken. The controller typically will cut out to protect the battery if the voltage gets too low. Yours starts at 36v, and drops to maybe 30v (from the spec sheet) for rated capacity. The controller may just be cutting out long before your battery is used up. You could get an idea of that by how long it takes to charge again. Also, I am not sure those batteries expect to deliver continuous amperage needed for an ebike.

Cheers buddy can you tell me which type of Lions I should be shopping for?

 

[Nealh]

thanks you might be correct as it recharges to full very quickly - less than 2 hours I suspect - but I will monitor it this afternoon to be sure, also I will check the voltage when it thinks it is flat. What I do notice is that the battery @monitor (which is 4 red less for full) goes from 3 lights to flat in about 500 meters.

What you see is voltage collapsing/sag, the batteries can not deliver the amp load asked of it.

 

[Nealh]

Cheers buddy can you tell me which type of Lions I should be shopping for?

For a li-on battery you don't need a hard case battery as you place your SLA's in a compartment/box so for a bit cheaper you can use li-on soft packs.
To ideally marry up a battery pack for you use we need to know the typical mileage and controller amp rating. Generally though any very good cell used will work for you, it just depends on your budget.
Using a li-on battery will also reduce bike weight which will help a little.

 

[wheeliepete]

This company would build you a soft pack to fit your box, the higher the Ah, the better your range, only really limited by your budget.
https://enerprof.de/product-category/batteries/ebike-and-pedelec-batteries/
Or contact Jimmy at Insat Int. UK company who will do the same.
https://ebikebatteries.co.uk/

 

[Nealh]

This the same people listing on Ebay.

This one is only 6ah but uses Samsung 30Q 15a cells. compared to your present battery arrangement the weight will only be about 10% of the weight with much better performance the softpack will be about 1.2kg in total. A simple 2a charger will be needed with suitable charge plug.
https://www.ebay.co.uk/itm/ENERpower-Softpack-Akku-Li-Ion-36V-10S2P-30Q-6Ah-Pedelec-Range-Extender-5-x-4/264115160058?hash=item3d7e7d83fa:g:HsAAAOSw6eRcLO-q:rk:23:pf:0

Typically I would expect about 15 miles range from this pack, a 10s 3p would be a very good option.

 

[Headshok]

so is the consensus to go with a 18650 cell pack over the batteries I have got? if so I might try building my own (depending on the cost of a welder.

 

[Nealh]

Yes.
SLA's are generally for instant amp draw high load rather then continuos use higher drain.
Best DIY spot welders are mini hand size Arduino ones cost about 130 euros plus a power source either high drain lipo for power supply so anther £50 - £60 or a very high amp rated sla. Not cheap for a one off so better buying a made to order cell pack.
You can buy larger Sunco welders for about £100 to £150 but they are not as good.

 

[Headshok]

Yes.
SLA's are generally for instant amp draw high load rather then continuos use higher drain.
Best DIY spot welders are mini hand size Arduino ones cost about 130 euros plus a power source either high drain lipo for power supply so anther £50 - £60 or a very high amp rated sla. Not cheap for a one off so better buying a made to order cell pack.
You can buy larger Sunco welders for about £100 to £150 but they are not as good.

yeah you are probably right I will get one made up - just emailed this guy in northampton 173701363297

 

[vfr400]

It's not worth the investment and effort to make a single battery. It will work out a lot more expensive and probably less reliable than a bought one. Only invest in self-building if you plan to make several batteries or your requirements are so specific that you can't buy one like that. Bear in mind that to make say five batteries would cost about £200 each to make by the time you've bought the equipment, wires, management systems, chargers, connectors and insulators, and you still need cases to put them in.

For this one, all you need to do is connect the two wires.
https://www.ebay.co.uk/itm/USB-Fish-36V15-6Ah-577Wh-Lithium-ion-E-Bike-Battery-Cycle-Lockable-Silver/302226989883?hash=item465e21e33b:g:zNIAAOSwuGxZlS9C&redirect=mobile

 

[Nealh]

yeah you are probably right I will get one made up - just emailed this guy in northampton 173701363297

Cells used are Sony NC1 they perform and sag worse then the Samsung 29E.

 

[Headshok]

Typically electric bikes use lithium batteries, and a 36v nominal one is actually quite a bit above when charged (42v), dropping as charge is taken. The controller typically will cut out to protect the battery if the voltage gets too low. Yours starts at 36v, and drops to maybe 30v (from the spec sheet) for rated capacity. The controller may just be cutting out long before your battery is used up. You could get an idea of that by how long it takes to charge again. Also, I am not sure those batteries expect to deliver continuous amperage needed for an ebike.

thanks so today I did a 4.3mile ride on it (towing) no use of the throttle, on LOW mode and even after 2 miles I was still on 4 leds, then 200 yards from home I went from 3 LEDs to 1 blinking LED and I popped the multimeter on and it says 44.7 Volts and 2 cells we 14.xx and one was 15.x.

So I am now thinking that my batteries are fine but my controller is cutting out way too soon?

 

[wheeliepete]

That will be voltage sag, and yes, it's the controller cutting the power. Might be worth checking your battery voltages with another meter, 14.xx is too high for a SLA battery, unless you have an alternator fitted to the bike.

 

[Nealh]

You need to rig up the volt meter for a reading whilst riding to see the actual voltage collapse as you go along . SLA's aren't usually able to deal with constant load and will sag badly inducing voltage collapse.

 

[BG bicycle]

These are Batteryblocs. Temporary pack, was to test some cells that were proven fakes. Long story that when the credit card company sorts out eventual divulge. Slam dunked Allybaba trade assurance with Samsung’s assistance and they still sided with the seller.

Advantage of this system is no welding, nor solder. And your cells are easy to replace or sell when cycle life drops.

 

[vfr400]

So I am now thinking that my batteries are fine but my controller is cutting out way too soon?

There is nothing wrong with your controller. It's electronic so it can't change any of its settings without someone opening it up, unsoldering components and soldering in new ones.

Your lead batteries are simply past their sell by date, which is the almost certainty that anyone will find when coming across one of these bikes. Replacement lead batteries wil cost between £70 and £100 for the three. You must make sure that replacements are for electric vehicles, like invalid buggies, golf carts or electric bikes. A lithium one costs twice as much, but will take you twice as far and weigh half as much.

 

[Headshok]

Hi all great news for me, I went to great shop in Swindon, and they provided me a new controller to take home and test, and it worked the same as my old one.

So I have ditched the lead batteries now and fitted a new 400Watts battery designed for the rear of a normal bike in a rack, and I have modified the rack to fit in the basket.

Its waaaay lighter than what I have removed, and has a light on the back also!

So I hope it will last for at least 10 miles (towing) and i will test it out tomorrow and I will update here with pictures

thanks for all your help and big kudos for this shop:

http://e-motionevc.co.uk/store/

While I was there I was able to drool over a a KTM fat bike, and the Risse and Muller Delite with Rolloff - in my size but not my wallet size!