We don’t often post on forums, but I think it is only fair to provide some factual balance on this topic:
Why we don’t make the NiMh battery packs anymore:
We did support the NiMh batteries continually for 11 years. We are a green company and wished to continue doing so for legacy customers but unfortunately, we could no longer get the NiMh charger, as the manufacturers ceased production. As a manufacturer ourselves we have to build in bulk, we cannot just make one NiMh battery pack, so once the chargers were no longer available, we had to be sure there was sufficient demand or we would end up with unsold packs ageing and then being recycled, which would not be green either.
In fact at the point we ceased production of NiMh bottles, demand was at a very low level because most customers tried Cytronex C1 before buying a new NiMh battery and decided to upgrade.
Please note it is incorrect to suggest that a Cytronex C1 Li-ion battery is a ‘’ridiculous price” of £995 – this is in fact the price for the entire kit about which AtoB said “without question, it’s the best power-assist kit on the market”.
Why we don’t make a compatible Lithium Ion battery for legacy Cytronex:
Designing a Lithium Ion battery pack is very different to a NiMh battery pack – safety has to be the first consideration and also factors like even temperature distribution are important for long life and safety. So, if the company referred to in this forum thread are packing anything like the quoted capacity into our original battery casing then I simply don’t see how that is ‘good practice’. It’s also not possible they can supply a 14Ah battery pack in our original bottle – the maximum that could possibly ever fit in the original bottle casing is 30 cells with no space for a protection circuit at all. This would provide a 10Ah pack according to the cell datasheet, but there would be no room for a protection module and in any case I am surprised these cells actually fit given the diameter. There would certainly be no room for expansion. So, for legitimate safety reasons, I would most certainly advise anyone who has this pack to ask the supplier to explain what the capacity really is, how they have fitted this capacity in the bottle casing (what is the configuration) and where they placed the protection circuit? I think it’s fair to say that as a reputable company with a quality product that I have personally invested all my time in over the best part of 14 years, I have deep concerns about battery packs such as those described carrying Cytronex branding on the casing.
In design terms Lithium Ion cells should be spaced and not touching, the pack should be designed with good temperature distribution for long life and the interconnects should be uniform such that there is not uneven resistance. None of these things would be possible with packing say 30 lithium Ion cells into our original bottle, if that is what is meant above. These considerations are different from NiMh packs. For the new Cytronex C1, because of the change from NiMH to Li-ion packs (which incidentally we manufacture here in Winchester) we changed the shape and design of the pack so it has no enclosed / surrounded cells for example.
We investigated many options for legacy customers when we launched C1, but I am sorry to say that every solution we investigated became too expensive to be viable. Customers would need the new bottle, which meant they needed the new bottle holder, which meant this needed new wiring. The end cost of which was prohibitive, especially considering the new bottle contains the main Cytronex electronics (designed and made by us here in England) inside, so the legacy controller becomes redundant.
Why we cannot recommend anyone else to provide a replacement service:
I see the first contributor said we would mention H&S – I wonder why they suggest (as a negative) that a reputable company like Cytronex should not be concerned with safety? To be clear – packing a large capacity lithium Ion battery pack into the space inside our original battery with 36V nominal, is not in our opinion safe and as a company we are bound by law to provide a safe product. Each different Lithium Ion battery packs need to go through rigorous testing to UN38.3 and I can tell you that the cost of this testing is in the region of £7,000. Clearly an individual making bespoke Lithium Ion packs for £300 has not invested this money like we are bound to do. Also, we have no idea of the quality of any protection circuit they may be using – we produce our own protection circuit and we manufacture our own lithium battery packs here in the UK tested to UN 38.8. So why would we (or how could we) recommend this as a viable and safe solution? We cannot.
I note that the above also says this company are providing a great service with collection and return of the above battery pack in the price of £300 (I just heard £320). The Li-ion pack size as described has to be transported as dangerous goods, so please confirm how they sent the battery back? Dangerous goods transport is very expensive and if the goods were sent without the proper labelling and transport considerations then there are obvious issues arising from that.
Richard – I am sorry we have not been able to meet your expectations, but we could not continue to provide support on an old system on a complementary basis. I note many emails to you, many sent late at night and certainly promptly, which is normal for us, so I don’t believe that can be described as “terrible after sales service”.
Despite the above I agree that I would love to have been able to offer a sustainable option for legacy system customers. I am passionate about reducing our carbon footprint and liberating bikes from sheds which is why I spent 9 years developing Cytronex C1 as a truly mass market product that consumers could fit to their own bikes without tools and the knowledge of some of those on this forum. There was simply no way to make the old and new systems compatible given the numerous and dramatic improvements in Cytronex C1. However, we offered Cytronex legacy for over 10 years and still support them as far as we can, so it is regrettable that we do not have a direct replacement battery. It is also worth noting that we are growing, whilst many of the ebike companies from when we started have now disappeared. This is because we are innovators – and back in 2008 we produced the first good looking electric bikes with the concept of a battery disguised as a water bottle. Currently we hold 4 international patents including our gear tooth sensor. Uniquely (as far as I am aware) we also produce our product here in England.
