Protecting battery from road shock and vibration

[James28]

I wanted to hear your views on how necessary you think it is to isolate a battery from the general road vibrations and shock you get from riding. Ie hitting a pothole hole or just a generally uneven surface.

Obviously full suspension bikes and fat bikes would have most of this isolated but what about fully rigid bikes? Are the batteries totally fine with the general vibrations and knocks you get from riding around?

My battery is mounted to a cross bike which i fitted some shwable big apples to to try and protect my components a bit.

When i designed my enclosure i did have this in mind but being limited with space I am limited on what i could do to isolate it.

I fitted foam around the battery in the enclosure and used bushings and more foam to fit the enclosure to some aluminium plates i have mounted on the frame. (My lifepo4 build thread has more detail of what i did)

Im just looking to make my battery box and small as i can so if its just not necessary to protect it like i have done then i can leave it out of my new design to keep the size down.

I thought this would be an interesting discussion, if the general consensus is that its not really known then im happy to go for it and report my findings after a few hundred miles.
Bear in mind im using lithium iron phosphate and not lithium ion cells

 

[portals]

My ebike has a 14S6P 52V 17.5Ah Hailong 4.5kg battery mounted using two screws for water bottle holder already available from the donor frame.

The plastic/Al connector attaches fine to bike and with battery mounted you find it naturally has a little sideways flex.

Personally I have never had any issues with this setup however given I have 1500W rear hub and am still a little paranoid about spin out I do not bump the rear wheel unnecessarily and try not to even jump of kerbs where possible.

 

[James28]

I have wondered how people managed to get away with batteries mounted only on the bottle cage mounts. It seems like a lot to put on 2 bolts to me.

I see no designs of ebikes (particuly factory ebikes) make much if any effort to protect the battery from shock. Maybe i just think they are more fragile than what they are.

1500w makes mine look like a childs toy

 

[guerney]

My bike has zero suspension and no options to add it, so I was a little concerned that battery pack welds could over time break with bashes etc. I thought about putting 6/12/18mm of rubber sheet (already have a roll of this stored in my loft. Very stinky) between the allegedly temporay pallet wood the battery mount, which is bolted through on the rear rack and held by locknuts underneath, to absorb shock...





...but then I realised that the bolts would also rise and fall independently, banging against the underside of the plastic battery case, therefore I'd need to insert a thin length of steel sheet in between those bolts and the battery case, to protect it's underside, if there's room. The battery pack itself rattled around inside the case, when things got bumpy, until I stuck heat-resistant (designed for placing between ceramic cooker and worktop) foam inside the case as padding.

Nothing's burst into flames yet.

 

[portals]

When I started researching parts then built my ebike (donor/1500W kit) I took it to local bike guy who did redid the rear hub drive train after a rear spin out.

I asked him about the weight of the battery in drink holder with only two screws and he was non-fussed so either didn't think it was an issue or didn't care.

Given the sheer differing amount of ebike systems/batteries available you see practically nothing about protecting batteries from shock so I don't really think it's an issue for most and wouldn't worry about it unless you have some out of ordinary setup.

1500W is a lot of fun but does need treated with some respect, I have the photos to prove it...

 

[soundwave]

the best way to make a large pack of 18650 cells is not to use nickle and use copper instead to make the connections as strong as possible tho most diy welders cant do it as not got enough power.

my m8s bafang hd has broken 2 of my old saddles rails in the same point so he needs some new bearings in that motor asap

 

[guerney]

my m8s bafang hd has broken 2 of my old saddles rails in the same point so he needs some new bearings in that motor asap

They're breaking because of how he's using those saddles - just look at that mad vicious insane angle! TF?!?!?!? I'll bet you a pint of Guinness he never fathers children... or any more children... or normal children...

 

[flecc]

I've never known batteries to need any protection from road shocks on rigid e-bikes, but their mounting platforms can suffer.

This post shows one such case and below my reply mentions similar that I suffered from a hard edged speed bump.
.

 

[soundwave]

the bottom of those forks blew apart few weeks ago and took a dump on the floor the motor needs new bearings as the controller is turned up to the max and nuked it for nearly 3 years

he does not paddle he has a button but jump off a curb and the chain falls off and the brakes are shite

 

[guerney]

the controller is turned up to the max and nuked it for nearly 3 years

That sounds like bloody good going, if it's the same controller being nuked for 3 years. Maybe Bafang HD MOSFETs are the ones we should be soldering into our 250W controllers... whichever MOSFETs those are...

 

[soundwave]

just get a hd and a 250w sticker the police dont give a **** as long as it does not make a noise

you just need a crash helmet and body armor to walk round the shop round here



try clamp that in a ulez zone

 

[Sturmey]

.............I see no designs of ebikes (particuly factory ebikes) make much if any effort to protect the battery from shock. Maybe i just think they are more fragile than what they are.

The older 2009 EN15194 did specify a requirement for mechanic strength but I am not sure of the position now.

4.2.3.7 Mechanical strength
EPAC shall have adequate mechanical strength and be constructed to withstand such rough handling that
may be expected in normal use. Compliance is checked by:
 applying impacts to the battery pack mounted on the EPAC by means of the spring hammer as specified
in IEC 60068-2-75. The battery pack is rigidly supported and three impacts are applied to every point of
the enclosure that is likely to be weak with an impact energy of (0,7 ± 0,05) J. After the test the battery
pack shall show no damage that could impair compliance with this European Standard;
 detachable battery packs are submitted to free fall at a height of 0,90 meter in three different positions.
After the test the battery pack shall show no damage that could lead to emission of dangerous substances
(gas or liquid) ignition, fire or overheating

 

[guerney]

just get a hd and a 250w sticker the police dont give a **** as long as it does not make a noise

you just need a crash helmet and body armor to walk round the shop round here

View attachment 51740

try clamp that in a ulez zone

Arnold Schwarzenegger Owns Tank He Drove in the Army

https://www.eightieskids.com/arnold-schwarzenegger-army-service-tank/

 

[AndyBike]

Feeling smug on full suss Ebike

 

[Nealh]

Decently built batteries with proper mechanical connections and cell holders are fine , glued cell packs may suffer issues with vibration and the glued surfaces failing but likely not with the mechanical connection.
Overall there is little to worry about from a commercial battery, the only real issues may be with diy builds and those who rely on glue and solder over far better mechanical connections.

 

[James28]

Decently built batteries with proper mechanical connections and cell holders are fine , glued cell packs may suffer issues with vibration and the glued surfaces failing but likely not with the mechanical connection.
Overall there is little to worry about from a commercial battery, the only real issues may be with diy builds and those who rely on glue and solder over far better mechanical connections.

My main concern is with the cells themselves.

I made a load of dummy cells out of pvc pipe (my cells are 33mm diameter x 140mm), put a wire through the middle, terminals on each end and filled them with sand to get the right weight.
I fixed the pack together as if i had the real cells in place and kicked it down the stairs, threw it out of a 2nd storey window and towed it around on the mountain bike for a while to make sure it would be alright.

 

[guerney]

My main concern is with the cells themselves.

Maybe compare battery cell temperature while vibrated on a plate and not, while providing power?

https://www.amazon.co.uk/Dripex-Vibration-Exercise-Resistance-Platform/dp/B0991NG27B/

https://www.amazon.co.uk/Jellas-Lightweight-Finishing-Collection-Mechanism/dp/B08CGMD7K1/

 

[AndyBike]

Personally I dont think it a problem because many off-roaders favour E-hardtails for their excursions. This involves rock gardens, drop offs and jumping.
I've long experience of HT's(non E's) and you do get battered about a fair bit.

 

[Nealh]

My main concern is with the cells themselves.

I made a load of dummy cells out of pvc pipe (my cells are 33mm diameter x 140mm), put a wire through the middle, terminals on each end and filled them with sand to get the right weight.
I fixed the pack together as if i had the real cells in place and kicked it down the stairs, threw it out of a 2nd storey window and towed it around on the mountain bike for a while to make sure it would be alright.

You sound like a mate of the wind up merchant who has posted on her the last two days, of course you pretend battery was alright it was only sand and sand can't catch fire.
Use real cell for a realistic result then tell us what happened as tbh no one maltreats a battery like that by just riding a bike.