20Ah batteries instead of 30Ah?

escooter

100 µW
Joined
Sep 5, 2019
Messages
7
I have a Daymak 72v-30Ah electric scooter and the batteries are worn out.
Can I install 20Ah battery? The 30Ah are very expensive and much heavier.
I know that the autonomy will be less, but in the month it will work!
here is a picture of my scooter controller



Thank you! :thumb:
 
I have a Daymak 72v-30Ah electric scooter and the batteries are worn out.
Can I install 20Ah battery? The 30Ah are very expensive and much heavier.
I know that the autonomy will be less, but in the month it will work!
here is a picture of my scooter controller



Thank you!
 
First, it's not good practice to post the same topic in multiple places.

I'm not familiar with Daymak, but first thing to check is how many connectors are leaving your current battery. If there's just two big cables it's easy to fit a different battery. If there are also smaller signal wires/connectors then the BMS is probably interfacing with other systems and it is not a straightforward swap.

A 72V20Ah battery will work in place of a 72V30Ah battery, as long as the BMS installed on the battery can provide the current required by the controller (looks like 50A max). Downsides are significantly decreased range and decreased battery life.
 
Yes for the multiple post, I did not know in which forum to put it !?
I forgot to specify that these are 6 lead/acid batteries of 12v 30Ah each.
There are only 2 cables (red/black) which go from the batteries to the controller.





30ah batteries are rare, expensive and heavy, just want the scooter work more of 20km! :?
 
escooter said:
I have a Daymak 72v-30Ah electric scooter and the batteries are worn out.
Can I install 20Ah battery? The 30Ah are very expensive and much heavier.
I know that the autonomy will be less, but in the month it will work!
here is a picture of my scooter controller



Thank you! :thumb:

20Ah vs 30Ah will affect the range of your scooter, but the types of cells and BMS used in the new battery will determine whether the new pack can provide the current that the scooter requires (20A-50A). 50A with a 20Ah pack would require good brand name cells, and higher discharge cells would provide some cushion.

EDIT: Ignore. Saw your double post.
 
Lead batteries will be able to handle the amp draw without damage. Your range will be a little less then 2/3 of what it was, but if your old batteries were really worn out, maybe that's still an improvement.
With a lithium battery, you would maybe worry that the same load spread out over a smaller battery would damage the cells, but lead is less sensitive that way.

It probably doesn't have a balancing system between the individual 12v blocks, but I've found that getting into manual balancing them pretty regularly radically increases the life span of a lead pack.
 
Is this lead battery? If so, you need to keep the 30 ah. The smaller battery won't have 1/3 less range, but more than half less. This is because as lead gets smaller, it tends to just use up all the energy heating itself up. A big enough battery stays cool, and leaves more energy for going forward.

To cut the weight, go to a 20 ah lithium battery.
 
If you stick with 30ah, there should be no regrets. Or you could compromise and get 25ah or 28 ah pack. 20 ah is probably too small for a heavy scooter.
 
Back
Top