Adding one battery in parallel to 5 serial connected battery pack

[presszz]

So, since my e-bike pack has some voltage issues + dropped range due to cold weather, i'm trying to have some range benefits by adding 1 more battery to in parallel.

My current pack is
12v 22ah x 5 = 60v (serial connected) Gel

By adding the same specs of 1 more battery to this pack in parallel, will i get any benefits?

My native languge is not english so i hope it is clear what i'm trying to explain.

 

[torker]

No . If you parallel more batteries it has to have the same voltage of the other series string. How old are the gel batteries?

 

[john61ct]

In parallel to a pack means at the same voltage.

Ideally same chemistry, so voltage follows same curve vs SoC.

Only Ah might be different.

If this is followed, yes will help. But of course imbalance issues, and will add weight.

 

[presszz]

No . If you parallel more batteries it has to have the same voltage of the other series string. How old are the gel batteries?

7 month old, i found and just bought the identical age and same voltage battery.

 

[john61ct]

Of course a brand new one, otherwise identical, would be even better.

Do a comparative capacity test using a CC load, your new-to-you pack might be NOS barely worn, or it could be in worse shape than your old one.

 

[presszz]

Of course a brand new one, otherwise identical, would be even better.

Do a comparative capacity test using a CC load, your new-to-you pack might be NOS barely worn, or it could be in worse shape than your old one.

Is this connection ok?

 

[999zip999]

Is best to keep at 12.6v or above. That's why they have RV float chargers. I mean they don't like to set after ride at low voltage. Charge them as soon as they cool off. Don't charge hot batteries for longer age. 13.6 volt is fine.
What you drew it up is wrong you want a series another battery for 60v.
let's have a look at your bike and see what kind of batteries we can fit on there cuz I might actually work. As lead is dead.

 

[john61ct]

I have absolutely no idea what that drawing is supposed to be about

 

[john61ct]

Let's use a standardized terminology here.

A "battery" will be a 12V unit, six cells in series or 6S.

A "string" will be multiple batteries in series, in this case 5S(6S) for 30 2V cells, which is how you are getting to 60V.

Now I interpreted what you want to do, is add another **one of those 60V strings** in parallel with your first original one, IOW five more batteries, each set identical within that string.

As I stated above, you cannot just add a random extra battery into a string, without changing the voltage. And you don't want to change voltage, that's a whole 'nother project.

Trying to just add one battery "in parallel" inside your existing string makes no sense at all

each member of a string needs to be **the same** Ah capacity.

Hope this helps.

And no, lead is not "dead", but it is certainly sub-optimal, and

in these propulsion use case circles, pretty much in a deep coma on life support, with a well publicised DNR order

 

[hemo]

Of course a brand new one, otherwise identical, would be even better.

Do a comparative capacity test using a CC load, your new-to-you pack might be NOS barely worn, or it could be in worse shape than your old one.

Is this connection ok?

NO.
You are trying to parallel a single 12v to a quintet of batteries = 60v.
You need 4 more 12v batteries to successfully make up two quintets of 60v then you can parallel together, but you will likely not fit them to your bike or gain much with any extra weight.
As john has mentioned try a more efficient energy source lithium or even lifepo4 if you like heavy.

 

[goatman]

why not disconnect all 5 batteries and check the voltage of each single 12v battery, maybe its just one of the 12v batteries is weak and causing the problem, if 1 battery is a different voltage than the other 4 batteries maybe just replace the bad battery with the new battery.

 

[999zip999]

Correct charge each battery to 13.6 volts if 13.8 volts well okay no more 13.6v is best let it sit or just parallel all the batteries all positive no one ever playing all natives if at same voltage that means if each 12 volt battery is the same voltage. well I don't know what their voltages are but if the same you'd parallel all them together put them on a 12-volt charger and leave them sit for a day or two watch for heat and or disconnect them and wait for three days and see what voltage each of the five or six batteries you have and that's the easiest cheat method

 

[john61ct]

Most lead requires lots higher than that to get to full.

My FLA's usually Absorb at 14.7-8, AGM 14.4V and GEL maybe 14.15V

For FLA and even some AGM, an "equalising" protocol at much higher maybe 15.5V, can help rejuvenate them a bit

Obviously follow the documentation specific to your cells.

 

[goatman]

yes but shouldn't I obviously bad battery be about 2volts less than the others

 

[john61ct]

2 batteries can both hold a charge the same, appear perfectly fine

but one is at 60% SoH (past scrapping time) while the other is at 80% (marginal but usable).

Only a CC-Load discharge test will tell the truth.

But sure sometimes they are so far gone it's obvious to anyone.

 

[999zip999]

The battery may take 14.1 v but it is surface charge. With no real capacity at that voltage. You get them to high and they will get more than a little warm.with no good results