Now I've got two KT controlled bikes, the next step is 48v rather than 36v. I've been looking at PSW's Hailong G70 batteries, mainly because the brackets have more fixing holes and seem to offer more flexibility in fitting in the restricted space in the frame triangle.

Cell types and capacities are a complete mystery to me so I'd welcome some comments on which of these is the better spec:-

 

48v. 15Ah with 3P13S Li-ion 5Ah 21700 39pcs battery cells (the interior battery is SAMSUNG INR21700-50GB 21700 Li-ion battery)

or

48v. 17.5AH with 5P13S Li-ion 65pcs battery cells (the interior battery is SAMSUNG INR18650-35E3 Li-ion battery)

https://www.pswpower.com/products/eu-no-tax-electric-ebike-battery-hailong-g70-samsung-lg-18650-cells-pack-48v-13ah-145ah-175ah-lithium-battery-fit-1000w-motor-108

 

Obviously the 17.5Ah has a claimed higher capacity and is more expensive, but are 18650 cells better then 21700? I'm thinking in terms of battery life and voltage drop.

They don't state weights, but I would imagine the 17.5Ah is much heavier? They are both the same size.

Lastly, there doesn't seem to be many outlets for G56/G70 style batteries. Is this because it's a relatively new product or being superseded by others? I don't want to find they are discontinued in a few years time.

Edited November 11, 20241 yr by Cadence

Now I've got two KT controlled bikes, the next step is 48v rather than 36v. I've been looking at PSW's Hailong G70 batteries, mainly because the brackets have more fixing holes and seem to offer more flexibility in fitting in the restricted space in the frame triangle.

Cell types and capacities are a complete mystery to me so I'd welcome some comments on which of these is the better spec:-

 

48v. 15Ah with 3P13S Li-ion 5Ah 21700 39pcs battery cells (the interior battery is SAMSUNG INR21700-50GB 21700 Li-ion battery)

or

48v. 17.5AH with 5P13S Li-ion 65pcs battery cells (the interior battery is SAMSUNG INR18650-35E3 Li-ion battery)

https://www.pswpower.com/products/eu-no-tax-electric-ebike-battery-hailong-g70-samsung-lg-18650-cells-pack-48v-13ah-145ah-175ah-lithium-battery-fit-1000w-motor-108

 

Obviously the 17.5Ah has a claimed higher capacity and is more expensive, but are 18650 cells better then 21700? I'm thinking in terms of battery life and voltage drop.

They don't state weights, but I would imagine the 17.5Ah is much heavier? They are both the same size.

Lastly, there doesn't seem to be many outlets for G56/G70 style batteries. Is this because it's a relatively new product or being superseded by others? I don't want to find they are discontinued in a few years time.

I have both types of cell in my main two 48v batteries. I can't say I can detect any difference. Tesla switched from 18650s to 21700s, probably for cost reasons.

 

Have a look at greenlance batteries. They're a UK supplier with good support. Prices are good and delivery is lightning fast. Use their code BLACKFRIDAY to get 10% off.

https://greenlance.co.uk/collections/48v-electric-bike-batteries

Yes, I've looked at Greenlance, but their battery carriers don't look as good an option as the G70 type. I don't need a controller compartment. There are four mounting holes on the G70 carrier and the battery has 4 evenly spaced locating clips. Only two of each on Greenlance's.

Greenlance are also more expensive, even with the 10% discount, than PSW's website store. I suspect that's because PSW don't charge VAT, but do on their Ebay and Aliexpress stores.

PSW 17.5Ah store price £198.29 inc. delivery (£237.00 on Ebay). Greenlance 17Ah £260.98 with discount.

Edited November 11, 20241 yr by Cadence

The 50Gs get a good review here

 

https://www.thunderheartreviews.com/2021/12/samsung-21700-50G-48G-50E-test-comparison.html

At the beginning of the year I had similar dilemma. I wanted to buy G70 15Ah, but I had to buy 17.5Ah because 15Ah was out of stock. 17.5Ah was significantly more expensive (I paid £240). I don't regret paying extra for 17.5Ah at all. It can keep my bike rolling for entire day (I didn't try long day 5AM-10PM yet, but I estimate it should be OK too).

15AH had better value for money, but it was worth to pay little extra for 17.5Ah.

Yes, I've looked at Greenlance, but their battery carriers don't look as good an option as the G70 type. I don't need a controller compartment. There are four mounting holes on the G70 carrier and the battery has 4 evenly spaced locating clips. Only two of each on Greenlance's.

Greenlance are also more expensive, even with the 10% discount, than PSW's website store. I suspect that's because PSW don't charge VAT, but do on their Ebay and Aliexpress stores.

PSW 17.5Ah store price £198.29 inc. delivery (£237.00 on Ebay). Greenlance 17Ah £260.98 with discount.

I always use a separate controller with those batteries, so I drill a hole in the aluminium heatsink in the battery base and fit a third rivnut into the frame in that position so that the battery is fully secure on the frame. Two screws are not strong enough to secure a battery of more than 40 cells (18650s).

I always use a separate controller with those batteries, so I drill a hole in the aluminium heatsink in the battery base and fit a third rivnut into the frame in that position so that the battery is fully secure on the frame. Two screws are not strong enough to secure a battery of more than 40 cells (18650s).

I've done that with the HL-1 bases and although it might help a bit I don't think it achieves much. It provides an extra fastening for the bracket to the downtube, but there are no plastic clips on the side at the controller box end to hold the battery to the bracket (see photo).

I've previously used two different types of downtube adapters, but these move the battery a few mm. up closer to the top tube - which is critical if I fit a taller battery.

The G70 has four evenly spaced plastic sliding clips on the battery to fasten to the base.

 

 

The four slotted screw holes also give a bit more flexibility in where to drill for rivnuts.

I've done that with the all-plastic HL-1 bases and although it might help a bit I don't think it achieves much. It provides an extra fastening for the bracket to the downtube, but there are no plastic clips on the side at the controller box end to hold the battery to the bracket (see photo).

I've previously used two different types of downtube adapters, but these move the battery a few mm. up closer to the top tube - which is critical if I fit a taller battery.

The G70 has four evenly spaced plastic sliding clips on the battery to fasten to the base.

 

[ATTACH alt=HL-1 BASE.jpg]60684[/ATTACH][ATTACH alt=G70 BATTERY AND BASE.jpg]60685[/ATTACH]

 

The four slotted screw holes also give a bit more flexibility in where to drill for rivnuts.

The battery's weight is downwards. It rests on the connector, so screwing that plate to the frame helps a lot. You can feel it when you wiggle the battery with only the top two screws in, then do that again after the third is fitted. it's definitely a lot stronget and more stable. Also, it stops the whole thing getting ripped off in a fall. I've been doing it this way for ten years of moderately rough cycling, and I always jump off curbs. It might not be the very best solution, but it's more than adequate.

 

The main point, though, is the UK supplier. There's probably more chance of your battery getting a problem than falling off your bike, so which are you going to care about most?

Thanks saneagle - more food for thought. I will be making up some cardboard templates to test clearances and potential screw locations when I can figure out how to enlarge to full size the few drawings that I can find on the web. There seems to be a dearth of these around, which is a bit surprising.

I can't find Greenlance battery dimensions now, but when I was comparing batteries few months ago, Greenlance batteries were not only more expensive than PSW, but also bigger.

I can't find Greenlance battery dimensions now, but when I was comparing batteries few months ago, Greenlance batteries were not only more expensive than PSW, but also bigger.

 

Thanks for the info. Does your PSW battery have an on/off switch? It's not clear from the web photos. In fact, a lot of sellers seem to inconveniently omit images of the charge socket side!

Thanks for the info. Does your PSW battery have an on/off switch? It's not clear from the web photos. In fact, a lot of sellers seem to inconveniently omit images of the charge socket side!

 

Yes, it does. I would never recommend battery without switch.

Edited November 11, 20241 yr by Az.

Thanks!

Thanks for the info. Does your PSW battery have an on/off switch? It's not clear from the web photos. In fact, a lot of sellers seem to inconveniently omit images of the charge socket side!

Greenlance use the 3-pin RCA type sockets for the charger, and they have switches that isolate the charge socket.

As a DIY battery guy, I often found that new name brand 5Ah 21700 cells were often the same price as name brand 3.5Ah 18650, so the 21700 builds were lower cost for me.

 

-Cost of goods? 65 18650 cells vs 39 21700 cells at 4-5£ (retail cost for me) per cell.

 

-Weight? 48 grams for an 18650 and 70 grams for a 21700, 65 vs 39 cells.

 

-Capacity? One battery is 15AH and the other is 17,5AH. That's just the battery specification based on low current tests, In the real world on an evike , you'll probably see less than that, but since these are name brand cells, they should maintain that capacity for a long time,

 

-Current. Knowing the cell brand/type, you can estimate high current performance

If Samsung 50G is 14A peak. that is 42A for a 3P battery,

If Samsung 35E is 8A peak, that is 40A for a 5P battery,

 

Be skeptical of those peak currents, because either cells will run pretty warm at 14 amps.. They also don't last long if run that high every day. It woulr be reasonable, in my opinion, to call them 30A batteries with the nod to the 35E's if you really were running a sustained 30A. Both should work OK with a 20A or 25A KT controller.

Now I've got two KT controlled bikes, the next step is 48v rather than 36v. I've been looking at PSW's Hailong G70 batteries, mainly because the brackets have more fixing holes and seem to offer more flexibility in fitting in the restricted space in the frame triangle.

Cell types and capacities are a complete mystery to me so I'd welcome some comments on which of these is the better spec:-

 

48v. 15Ah with 3P13S Li-ion 5Ah 21700 39pcs battery cells (the interior battery is SAMSUNG INR21700-50GB 21700 Li-ion battery)

or

48v. 17.5AH with 5P13S Li-ion 65pcs battery cells (the interior battery is SAMSUNG INR18650-35E3 Li-ion battery)

https://www.pswpower.com/products/eu-no-tax-electric-ebike-battery-hailong-g70-samsung-lg-18650-cells-pack-48v-13ah-145ah-175ah-lithium-battery-fit-1000w-motor-108

 

Obviously the 17.5Ah has a claimed higher capacity and is more expensive, but are 18650 cells better then 21700? I'm thinking in terms of battery life and voltage drop.

They don't state weights, but I would imagine the 17.5Ah is much heavier? They are both the same size.

Lastly, there doesn't seem to be many outlets for G56/G70 style batteries. Is this because it's a relatively new product or being superseded by others? I don't want to find they are discontinued in a few years time.

Hi , I own the 15ah battery from PSW and it's great, I also have the 12.5ah one with the 18650 china cells and it's heavier than the 15ah with the 21700 cells, performance seems the same

I always use a separate controller with those batteries, so I drill a hole in the aluminium heatsink in the battery base and fit a third rivnut into the frame in that position so that the battery is fully secure on the frame. Two screws are not strong enough to secure a battery of more than 40 cells (18650s).

Mine hold fine on 2 bolts, no problems, biggest is 48v 20ah

Thanks for the info. Does your PSW battery have an on/off switch? It's not clear from the web photos. In fact, a lot of sellers seem to inconveniently omit images of the charge socket side!

Yes they all do

Mine hold fine on 2 bolts, no problems, biggest is 48v 20ah

A 20Ah HL type battery will hold fine with one screw if you keep your bike parked in your shed.

Two screws are not strong enough to secure a battery of more than 40 cells (18650s).

 

Two screws, 65 cells and it holds fine on two bolts.

Two screws, 65 cells and it holds fine on two bolts.

Until it doesn't. You could just as easily argue that seatbelts in cars are unnecessary because you drive without one and have never been thrown through the windscreen, or you don't need a fuse on your lights powered by the main battery because the wires have never shorted.

Edited November 19, 20241 yr by saneagle

A 20Ah HL type battery will hold fine with one screw if you keep your bike parked in your shed.

lol , I do roughly 15,000k a year

Until it doesn't. You could just as easily argue that seatbelts in cars are unnecessary because you drive without one and have never been thrown through the windscreen, or you don't need a fuse on your lights powered by the main battery because the wires have never shorted.

Not the best analogy, 3 bolts aren't enough either then ...........

Until it doesn't.

 

I can say the same about keeping battery at home.

 

I will start to worry when I see people here reporting problems, but I hear what you are saying... it might be worth to add some extra protection.

To conclude this topic, I finally pulled the trigger on a 48v 15Ah G70 Hailong battery from PSWPower. When trying to order on their website a message comes up saying they do not ship batteries to the UK. However, in response to an email request I got a Paypal invoice for £159.74. The battery arrived in 4 days with no further charges for VAT or duty.

The G56/G70 battery carrier has a full length aluminium rail that I was able to use without drilling my bike frame:-

 

I removed the two middle (of 4) small nuts and screws and the holes were almost spot-on for the bottle cage mounts, so I opened them out with a 5.5mm drill and slightly elongating one of them. I've tried mounting the battery and riding over some quite deep potholes - in conjunction with an old fashioned toe strap the battery is held firmly and doesn't even wobble slightly.

What a difference 48v. makes! I have a KT 15A controller which I had previously shunt soldered to I guess around 18A. This was fine with 36v., but on test with 48v. I found that PAS 1 was just too powerful. PAS 5 was ridiculous- steep hills flattened and controller and motor still cold to the touch. I've since knocked the C5 setting back to 8, which I guess is around 15A. This gives more control in the lower PAS settings and the bike still goes up hills like they hardly exist.

I have my Yosepower Hailong HL-1 battery carrier mounted on a piece of marine plywood on top of the rear rack so I can carry the 36v. 13Ah as a spare range extender if needed:-

 

 

The controller sits in an electronics enclosure box (with ventilation holes in the bottom) on the rack stays but I've not bothered with any fancy switchable wiring. There is an XT60 plug on the end of the controller cable and each battery carrier has an XT60 socket cable concealed under the rack. I can just pull them out and swap them over when needed. With panniers mounted, this is my "long range tourer". In reality I doubt I'll ever need to use the full range of both batteries but it's nice to have a bit of "insurance" on long rides.

BTW, the motor is Yose Power's 250w. cassette version and performs very well on both 36 and 48v.

Edited May 7, 2025May 7 by Cadence