Charger Recommendation for 24V or 36V batteries

[13R41N]

I recently bought a cheap Schwinn AL1020 ebike and the charger was not included. The battery in the bike is a 24V (2 x 12V12ah batteries wired in series.) I have managed to find out the original charger was a 24V 1.8A charger. I was thinking of trying to source a car battery charger at Canadian Tire that will fulfill this requirement.
I was also think of purchasing another 12V battery to run in series to increase the speed of this bike. Will it be possible to use the same 24V 1.8A charger to charge the 36V battery or will I need to source something more powerful?
Any feedback and charger recommendations are appreciated.

 

[john61ct]

Bargain for $90, but a PSU not a charger https://www.ebay.com/itm/254715338387


Satiator model# 4808 "24V-52V" output range 24-63V @8A (manual states 12-63V), about $300

Few are that adjustable, most just buy a charger for each voltage they need.

 

[Wolfeman]

Maybe you can benefit from my experience here.... I've run different bikes at several different voltages (48-84V) and have repeatedly gone for the "circuitboard in a piece of rain gutter with a fan" chargers. In the four years I've been doing ebikes, I think I've bought 7 or 8 different chargers, usually costing roughly $79 to $129 each. After the first 2 chargers I started looking at the Cycle Satiator, but always decided to, "save money" and buy yet another cheapie.... Whoops

The above advice of course will only apply if you, like so many of us here get "bitten" by the ebike bug and go flying down the wormhole in a cloud of dust and ozone, gripping the handlebars tightly, feeling like a little kid on their first mini bike or dirt bike, constantly wondering what it would be like to push "just a few more" volts or amps through whatever faithful brushless servant is bolted to our trusty steeds.

Ah, ebikes....

 

[MadRhino]

Would be good to know battery type at least. From your post I would be tempted to think SLA, which is very uncommon nowadays.

 

[13R41N]

Would be good to know battery type at least. From your post I would be tempted to think SLA, which is very uncommon nowadays.

yes it is a battery pack with 2x12v12ah SLA batteries inside wired in series, sorry I forgot to mention that in the initial post. Does that make a difference in the type of charger I use? I was thinking of buying a charger for a cordless drill battery at the local reuse it centre. Something with 24V 1.8A rating if I can find it, or maybe a laptop battery charger with that voltage/amperage rigged up correctly to the positive and the negative. Would that work?

 

[MadRhino]

SLA batteries don’t need balancing and can be charged pretty fast. I would use a simple PSU, or a SLA charger.

Their downsides are poor density and short life. Their performance decreases quickly. If you plan higher voltage and longer range, Li chemistries would be a good investment.

 

[john61ct]

Proper deep cycling lead batteries can cost a bit more, but last a lot longer

best to stop discharging around 50% SoC to get a decent long life.

And take 5+ hours to get to Full, unlike LI you want lead to be at 100% SoC for as much of their lifespan as possible.

But 2-4x more weight and bulk than LI, hence hardly used for propulsion energy anymore

 

[13R41N]

Thanks for your replies. I went to the local recycling depot and found a few batteries that had some charge in them. I took the smaller SLA ones and added some distilled water and charged them individually with an motormaster intelligent 12V battery charger. It went into a reconditioning phase and then a low amperage charge(1A-2A) and after several hours they became fully charged. I decided to hook the 12V12Ah and the 12V14Ah batteries in series and the bike is fully operational.
1. @MadRhino if these SLA batteries dont need balancing is it ok to run the 12V12Ah and 14Ah in series or am I going to run into some problems?
2. i have a 12V34Ah SLA which is much bigger. I was thinking to run this in series also to have a 36V battery. I would imagine the 2 smaller batteries would die first and then the larger one would provide all the power at the end. Not sure if you have any experience hooking different AH same voltage batteries in series, but any feedback is appreciated.
THanks again

 

[Balmorhea]

Once the smallest (as in smallest actual capacity) battery is exhausted, you're done. However much energy is left in the larger batteries doesn't help you, unless you can use it at lower voltage after taking the dead one out of series.

It sounds like a recipe to send the small bricks right back to the recycler.

 

[999zip999]

So you're running at 36 volts now ?
These people have used and new premade batteries different all the time.
https://batteryhookup.com/products/complete-mercedes-oem-lg-chem-12s-44v-20ah-880wh
Not this one but maybe later they may offer something cheap.

 

[13R41N]

Once the smallest (as in smallest actual capacity) battery is exhausted, you're done.

So if I understand correctly, essentially if I connect the 12V12ah, 12V14ah and 12V34ah in series to create a 36V then the system will only work until the 12V12ah drains? When you say I’m done, you are referring to the batteries needing a recharge not to the batteries blowing up, right?
Is there a risk of anything seriously wrong happening if the capacities are different and in series. Let’s say if I only use the 12v12ah and the 12v14ah, is the risk minimized because they are more closely matched?

 

[13R41N]

So you're running at 36 volts now ?

Im waiting to plug it all together but not yet. I want to make sure that running the 3 batteries in series with different capacities is not going to cause any serious issues like exploding batteries. If I understand @Balmorhea correctly, it sounds like the system will work but once the smallest battery is finished the system "is done", which I interpret as needing a recharge. If the 12v36ah isn't going to add much more to the system I will see if I can source another 12V12ah or 2 more 12v14ah to save on weight and size restrictions.

 

[john61ct]

SLA means cannot add water, those are FLA.

IMO wasting time messing with old scrapped units,

if you are in the US, good quality true deep cycling lead is ~$70 per kWh brand new

But each their own

 

[john61ct]

Since you like cheap stuff

https://endless-sphere.com/forums/viewtopic.php?p=1584849#p1584849

lots of flexibility up to 60V, can also do single units at 2/4/6/12V

 

[999zip999]

7ah 14ah 14ah is 7ah @ 36v

 

[Balmorhea]

So if I understand correctly, essentially if I connect the 12V12ah, 12V14ah and 12V34ah in series to create a 36V then the system will only work until the 12V12ah drains? When you say I’m done, you are referring to the batteries needing a recharge not to the batteries blowing up, right?

If you keep pushing the string of batteries once one is depleted, you'll destroy that one. Whether it outgasses enough to pop open, I can't say. But you will kill it.

In your case, you'd be better off putting the 12Ah and 14Ah batteries in parallel with each other, then in series with the 30-something Ah battery.

It still approaches a total waste of time, but you'll get a lot more range that way.

 

[13R41N]

I charged the 12V12ah and the 12V14ah individually with a 12V 2A charger, connected them in series and then rode the bike a few km's. Then I charged the series circuit with a 24V 1.8A charger. I left the house for a few hours and when I came back the charger indicated it was fully charged. Later in the evening I noticed my battery packs were a little WET and a small puddle was under my bike. I inspected the batteries and the 12V12ah seems to be the one that is the one letting out the moisture. However, It does not look damaged in anyway.
Not sure if the liquid is present from using the battery or from charging the battery.
Do you think this is a result from charging different capacities (12ah &14ah) in series?
I had added distilled water to the batteries before the initial 12V 2A charge with no escaping water, could it be water escaping from the initial usage.

 

[markz]

Canadian Tire

Crappy Tire is an option, your better off getting a better battery and a decent charger.

Where you at in Canada?

 

[E-HP]

I charged the 12V12ah and the 12V14ah individually with a 12V 2A charger, connected them in series and then rode the bike a few km's. Then I charged the series circuit with a 24V 1.8A charger. I left the house for a few hours and when I came back the charger indicated it was fully charged. Later in the evening I noticed my battery packs were a little WET and a small puddle was under my bike. I inspected the batteries and the 12V12ah seems to be the one that is the one letting out the moisture. However, It does not look damaged in anyway.
Not sure if the liquid is present from using the battery or from charging the battery.
Do you think this is a result from charging different capacities (12ah &14ah) in series?
I had added distilled water to the batteries before the initial 12V 2A charge with no escaping water, could it be water escaping from the initial usage.

You overcharged the smaller capacity battery so it started gassing. Normally cells in series should be the same capacity so they stay in balance. Not possible when the cells differ in capacity, since even if both start out fully charged, the smaller pack with drop voltage faster as it discharges.

 

[999zip999]

Batteries must all be the same 10 ampere hour or more but the same bought at the same time have the same voltage have the same capacity. You're only going to get in trouble with having different ampere-hour batteries
You can still start fire with SLA batteries can you compare yourself with the acid be careful.
save up your money get up 36 volt battery with BMS and charger all from the same place

 

[13R41N]

Canadian Tire

Crappy Tire is an option, your better off getting a better battery and a decent charger.

Where you at in Canada?

Im on the west coat north of Vancouver. I sourced the original charger for the bike from the re use it centre where I originally bought the bike. The original charger is a 24V 1.8ah and the batteries are 12V 12ah. I'll pick up a few new 12V14ah batteries to get a little bit more Ah. Batterclerk.ca has AJC branded batteries and they will deliver them to me for a decent price. Are AJC good batteries?