Ebike batteries life increase questions

Batteries, Chargers, and Battery Management Systems.
Post Reply
samenameall   10 µW

10 µW
Posts: 5
Joined: Aug 13 2017 10:39am

Ebike batteries life increase questions

Post by samenameall » Aug 13 2017 3:19pm

Hello, I replaced my 4x sealed lead acid batteries for my ebike recently (they are total 48V 20AH) because the old ones got inflated (probably from overcharge, even thought my charger has overcharge protection). The questions I have in order to make my new batteries to last longer are:

1. Instead of performing a full charge (which I think caused my old batteries to inflate) that takes around 6-8 hours is it better to charge them for specific time let’s say 5 hours each charge (so basically make charges around 90% instead of 100% to prevent overcharge / inflate)? Will 5 hours charges / 90% charges help my batteries last longer?

2. Any suggestions in general to make my new sealed lead acid batteries last longer?

3. How much longer time Lithium type batteries last than sealed lead acid batteries? My old sealed lead acid batteries lasted like 3 to 4 years max if they were lithium type would they last longer?

Hillhater   100 GW

100 GW
Posts: 10527
Joined: Aug 03 2010 10:33pm
Location: Sydney ..(Hilly part !) .. Australia/ Down under !

Re: Ebike batteries life increase questions

Post by Hillhater » Aug 13 2017 4:51pm

3-4 years life from Lead/acid batteries on an Ebike (or anything !) is a good result !
If you think they were over charged,...get your charger checked.....but i doubt there is much wrong.
If you plan on using Lead again, the best option is to buy batteries with a 5 year replacement guarantee. !
.. And yes, Lithium will perform better in many ways, ....life, power, size , weight, and even overall cost $$$s/year.
This forum owes its existence to Justin of ebikes.ca

zackclark70   100 W

100 W
Posts: 205
Joined: Feb 21 2014 4:46am
Location: My House UK :)

Re: Ebike batteries life increase questions

Post by zackclark70 » Aug 13 2017 5:25pm

my a123 amp 20 have had nearly 1000 cycles over the last few years they have lost 20% capacity but still plenty good

just got myself a 2.7kwh 16kg lipo pack with charges at 1c and discharges at less than 1c it should last 600 cycles before its lost to much capacity

User avatar
The fingers   100 GW

100 GW
Posts: 7169
Joined: Mar 11 2012 11:22pm
Location: Desert Pacific Cali USA

Re: Ebike batteries life increase questions

Post by The fingers » Aug 13 2017 5:50pm

My http://www.batterysaver.com/ charger/maintainer gave me an extra years worth of commuting when my SLAs began to sag. :wink:
Black Schwinn High Sierra
Blue Schwinn Cruiser 5
Blue Schwinn High Plains
Black Fiore Cruzer 5: Amped Warp Drive 26" Front DD/SLA kit
http://ghostbikes.org/
http://www.rideofsilence.org/main.php
Hebrews 9:27

User avatar
Sunder   100 MW

100 MW
Posts: 2838
Joined: Sep 06 2011 11:24pm
Location: Sydney, Australia

Re: Ebike batteries life increase questions

Post by Sunder » Aug 13 2017 6:23pm

Swelling of the battery only happens for two reasons. Overcharge and short circuit. If the charger is fine and you didn't externally short circuit it, then it internally shorted. Given the age, internal short is very likely, bit the swelling probably occured because the short means you now have a 5 cell battery being charged by a 6 cell charger.

If longevity is what you are after, I wouldn't replace with SLA. But since you have, you're stuck with it. The advice for SLA is:

1. Always keep topped up to 100%. 90% charges or less shorten life

2. Don't discharge below 50%, and if you do, charge up as soon as you can.

3. Keep the rate of charge and discharge low. You get less damage to your lead plates.

4. Desulfate your batteries and equalise them once a month. This prevents loss of capacity through undissolved lead sulphate crystals and undercharged cells.

The life of Lithium based batteries depends on quality and care. Top quality LiPo cells kept under 25*C, charged to 3.92v or less can last 8-10 years with 5000-10000 cycles.
eBike: Q100H on 16S with Phaserunner FOC Controller
eMotorscooter: Vectrix VX-1 on 36S
eCar: Mitsubishi Outlander PHEV... Waiting for warranty to expire
eHouse: 5.5kw On-grid solar with battery backup coming soon!

After 5 builds, the best advice I can give, is start with high quality products. I prefer http://www.ebikes.ca

samenameall   10 µW

10 µW
Posts: 5
Joined: Aug 13 2017 10:39am

Re: Ebike batteries life increase questions

Post by samenameall » Aug 13 2017 7:02pm

Sunder wrote:4. Desulfate your batteries and equalise them once a month. This prevents loss of capacity through undissolved lead sulphate crystals and undercharged cells.
How I can do this on sealed lead acid batteries? I need a special charger or I need to do it manually?

User avatar
Sunder   100 MW

100 MW
Posts: 2838
Joined: Sep 06 2011 11:24pm
Location: Sydney, Australia

Re: Ebike batteries life increase questions

Post by Sunder » Aug 13 2017 7:45pm

The charger that "The Fingers" linked, is a desulphating charger. Anything that sends high frequency pulses through the battery is a desulfating charger. Apparently some frequencies work better than others, but there's never been any conclusive research that I've seen.

As for equalising charge, you need a charger that can either do it, or power source that can supply 15v at the minimum current necessary to reach that voltage. Sealed Lead Acid batteries shouldn't be equalised as often as flooded lead acid batteries, and keeping the current low is more important, as you can't top up any acid boiled off.

If you are hard on your batteries (High amp draw, leave below 90% charge frequently, etc.) you would want to do it more often (monthly), and longer (4+ hours). If you're fairly easy on your battery, e.g. they're over sized, gentle amp draw, charge at both sides of the trip, every 6 - 12 months for an hour or two might be enough.
eBike: Q100H on 16S with Phaserunner FOC Controller
eMotorscooter: Vectrix VX-1 on 36S
eCar: Mitsubishi Outlander PHEV... Waiting for warranty to expire
eHouse: 5.5kw On-grid solar with battery backup coming soon!

After 5 builds, the best advice I can give, is start with high quality products. I prefer http://www.ebikes.ca

User avatar
Rassy   10 MW

10 MW
Posts: 2020
Joined: Apr 08 2007 10:58am
Location: Eugene, Oregon USA

Re: Ebike batteries life increase questions

Post by Rassy » Aug 13 2017 7:49pm

What Sunder and The Fingers said. Here's the one I have:

https://jet.com/product/detail/badb211e ... f1d54f656f

Wow, never saw such a long address to a page. Okay, when I submitted this page it was edited down. The charger is an "Xtreme battery charger", and sources will show up if you just enter that.

I still have one 12V 8AH battery left over from the "old" days of SLA and it is virtually perfect. Mainly used to inflate my air mattress when camping, and always charge it before and after usage with the Xtreme charger. The battery is over a decade old now.

I would say you should put the desulfating charger on different batteries overnight, whenever convenient.

My 2012 Honda CRV, actually all 2012 Honda CRVs, had a faulty charging algorithm that left the battery undercharged and wasn't corrected for 2 1/2 years, all unknown to me until it started to fail earlier this year and Honda said it needed to be replaced. I remembered the Xtreme charger, and have used it when the car is parked at home for the last several months. The battery is responding, but too early to say if it has recovered fully. If I wasn't so stubborn I'd just get a new battery, but I want to see how long I can make it last! :D And just in case I do have AAA and also one of those little starter battery packs.
-Rassy-
One Tadpole Trike equipped with a Bafang BBS02
https://endless-sphere.com/forums/viewt ... 28&t=69419
One Delta Trike equipped with a Bafang BBS02
https://endless-sphere.com/forums/viewt ... 0#p1291260

User avatar
dogman dan   100 GW

100 GW
Posts: 35305
Joined: May 17 2008 12:53pm
Location: Las Cruces New Mexico USA

Re: Ebike batteries life increase questions

Post by dogman dan » Aug 14 2017 6:28am

You did great to get 3-4 years!

The swelling is caused by sulphate crystals, that grow no matter what. But they grow a lot faster as soon as the battery is not 100% full.

If your charger keeps them at 13.5v per cell, that is not overcharging them any. But the charger should be going into maintenance mode when full, not pushing full current like a dumb vintage car charger can. You should not leave it on the charger constantly even with a smart charger, unless needed to get back to full. In storage, just top up monthly or so, not leave it on the charger.

FWIW, lead is very different from lithium. to make it last, charge it 100% asap each discharge. Then on the discharge, stop at 50% if possible, and 80% if you must go farther.

If at all possible, like at work or something, charge before you start home. Keeping the battery between 80 and 100% full even better than between 50 and 100% full.

Post Reply