e-touring and battery safety

[ChrisF]

I've recently added an e-kit to my old Galaxy tourer, with the idea of taking it on extended tours (when we are allowed to again!) - I can't do hills any longer when loaded up with luggage. I was a bit surprised, though, to find very strict instructions about charging the battery:

If charging inside your house, keep an eye, unplug the charger when the light turns green, then take the battery outside. Do not leave the battery on charge if you are going out or when you are asleep

Now, I realise that this is to cover the very small possibility of rare events when something goes wrong - if all is working correctly, the battery's management system should stop charging automatically at the correct time. And, when at home, I could fairly easily live by these instructions if I don't use it every day - but I'll rarely be using this bike when at home.
If I'm touring, I'll typically arrive at a B&B or hotel around 6pm, and some days the battery will be flat by then. It's 17.5Ah, and with a 2A charger it takes 9 hours to charge. So it will have to be charging while I sleep (and go out for a meal) if I want to use it again next day. What's the solution? Not to worry about it all all, and ignore these instructions? Take along a small plugtop timer to turn it off after 9 hours? It's still going to be totally impractical to take the battery outdoors afterwards!

Any thoughts?

[lowrider]

Hi,

Get a higher ampage charger just for touring. What size will depend on the particular cells used in your pack and what it can cope with but 3A will be approximately 6 hrs 4A 4.5 hrs. Rarely will you need the full charge and six hours is much easier to manage.

The constraints of the battery might mean your days are shorter than your used to un assisted. Based on a few assumptions and10 miles an hour moving average, even with a 17.5ah battery (36v) I would of thought that your range would be about 50 to 60 miles. Starting at say 9am that would be a moving time of 5 to 6hrs. Thats 3 to 4hrs stopping time assuming a 6pm finish.

The timed plug seems like a reasonable Idea to stop it charging overnight if thats a worry.

I suggest you do use the bike fairly regularly to maintain the battery.

[stodd]

9 hours is quite a convenient time; plug it in shortly before bed and you should be awake in time to unplug in the morning. You could even take it outside then, but that does seem a bit extreme. If it were significantly less (eg after a lazyish day) that would be more of an issue.

[ChrisF]

Thanks for the replies. I hope to be doing up to 80 miles some days - I did that last week, on a test ride , without luggage, and had plenty of battery left but of course more will be used with the extra load.
I'll think more about the timer - but I suppose my sub-text is, does anyone actually worry about these things? Do others just plug in the charger and leave it charging while convenient, rather than looking for a green LED all the time?

[Oldjohnw]

Mine takes about 4 hours. At home I tend to check it. When camping at a site I have often left it locked in the office overnight.

I don’t really know what can be done.I have read the very occasional report of fire as with phones and laptops/tablets. And fridges and tumble dryers. There doesn’t appear to be a pattern and I am not aware of any additional safety measures introduced.

Some imported chargers have been blamed in the past.

[nez]

my neighbour set fire to his house by leaving his laptop on charge overnight - but what are we to do, if you want to use it in the morning. I have an ebike with a Bosch system and have been warned by two separate dealers* to keep the battery in the house - so where will I charge it?

* I once had a battery go u/s on my wife's bike and it cost £700 to replace. Dealer blamed low temps outdoors

[Red Kite]

Almost nothing is entirely risk-free, so we accept very small risks all the time whether we think about it or not.

It is a certainty that some houses will catch fire because of resistive heating at poor connections in the house wiring - my house was badly damaged by fire in 2019 when a loose connection in a junction box overheated and started a fire in the roof space (this being the most likely cause in the opinion of the forensic investigator appointed by the insurer). There are millions of such junction boxes throughout the land. Many will have a loose connection somewhere. If one in a million starts a fire in the course of a year, that's still a lot of fires.

The insurers paid out, the total claim being c. £250,000. There was nothing in the policy to the effect that I should not have had junction boxes or that all the connections must be re-tightened from time to time.

What worries me about the bike battery fire is that the policy might have a clause that obliges me to follow manufacturers instructions in regard to charging, or such an obligation might well be an implied condition.

The Bosch battery manual says, among other precautions -

Do not place the charger or the battery near flammable materials. Ensure the battery is completely dry
and placed on a fireproof surface before charging.

The eBike battery must not be left unattended while
charging

Once charging is complete, disconnect the battery from the
charger and the charger from the mains.

I might accept the tiny risk of a fire. But would my insurer pay out if my house was destroyed as a result and I had not followed the instructions? Not many could afford to lose their house if the worst did happen.

[nez]

I think left unattended means ‘don’t go on holiday’ not ´sit watching’. However these terms are always designed to trip you up, as we all know. When I was knocked off a motorbike 25 years ago the fault insurer tried to insist under the rules then the mb dealer fit my engine into a new frame. ´no thanks’ the dealer said ´I prefer to sleep at night.’ Then he rang me to tell me!

[willcee]

I have built quite a few machines with kits, however and i cannot emphasise this enough , none of the power packs were built in China, they were built here using good dependable 18650 cells and expensive BMS boards and properly checked and tested before delivery, yet me being me i for the first few cycles of recharge watched them like an expectant mother , that said when the light goes green the power shuts off.. since then nearly 4 years ago i'm more relaxed and charge in house in the big kitchen most of the quality charger have internal fans and those shut off when the green led appears signalling all is over .. watch however if anything gets warm i mean warm not tepid, a fan blasting often helps..
To address the touring situation I consult for a cyclingtouring co. and we had this situation back in 2018 and 19 when things were live Often small hotels and those outside of group ownership have garages and workshops which if you ask before hand would permit outside charging, take a tin lid with you in your panniers and place the battery atop when charging.. and as the OP has said amend your days and make £ friends with the people at reception.. who taught me this, personally, a lifetime on the road, and a good friend now deceased,who worked abroad in the 70's and 80's in the oil biz, middle east mainly, I have been with him in Dublin at the Horse Show and saw him drop a 20 to the girl on reception who split it with her male co worker, he could have committed murder in there... no one who have said boo.. 20stg at that time in Dublin was money.. will

will