Don't Miss

Increasing Back Up Of Resonate Router UPS MODEL-CRU12V2A

By Jestine Yong on March 9, 2024

This UPS was brought to me by my elder son during one of his regular visits. He said that the backup time had reduced drastically and he wanted me to provide a good back up as he was facing frequent power shutdowns for a prolonged period. On opening and checking, I found the unit was using three 18650, 3.7V Li-Ion batteries. Let us have a close look at the insides:

I got a replacement with better mAh (Geepas 5000mAh, 3.7V) rating and joined them in the best possible way sans the Li-Ion battery welder:

You will notice from the pictures that the battery charger cum protection board worked on a single battery to perhaps get 3.3V or 1.8V or 1.2V that might be necessary and charged the cells sensing at each stage. That’s why you will find B- in one place, but B+ in three places in the board; +B1, +B2 and +B3. I also noticed while testing that this was an online UPS, i.e., always working from the battery. Hence, if the on/off switch is not slid to the on position, even charging of battery will not take place. For proper functioning, the voltage from the battery must be connected and that is what was getting switched off by the on/off function and not the power output!

After putting the unit for full charge which is indicated by red-amber-green LED, I connected the unit to the Router in the home and allowed it to run without the AC power inlet Adapter. My son was so happy that the backup lasted for more than 7 hours!

Before concluding, let me tell you that the UPS is very compact and designed very well. It used double sided PCBs which are costly and intricate.

So, I know what you are waiting for: Mission successfully accomplished to qualify the resultant double satisfaction get into the bag. Why double? Because, the work done was for my son! (LOL)

This article was prepared for you by Parasuraman Subramanian from India. He is 74 years old and has more than 30 years’ experience in handling antique equipment like Valve Radio, Amps, Reel Tape Recorders and currently studying latest tech-classes conducted by Kerala State Electronics Technicians’ Association. He has done graduation in BBA degree, private diploma in Radio Engineering and retired as MD of a USA company. Presently working as Consultant to Hospital and other institutions.

Please give a support by clicking on the social buttons below. Your feedback on the post is welcome. Please leave it in the comments.

P.S-If you enjoyed reading this, click here to subscribe to my blog (free subscription). That way, you’ll never miss a post. You can also forward this website link to your friends and colleagues-thanks!

You may check on his previous article on Saved EVEREADY LED Bulb And LED BATTEN From Dump

Likes

(42)Dislikes

(0)

UPS Repair

6 Comments

Tayo

March 9, 2024 at 11:39 am

Another well played repair Sir. These 18650 batteries are a whole other can of worms that techs will need to be gain a level of expertise in. Over here in the US everythibg is going battery powered (even lawn equipement) and the cells of choice are these 18650 and their bigger capacity cousins the 21700. One bad cell will usher in the demise of the entire battery pack in short order. The BMS is also a point of contention as they are often poorly designed. Ive dabbled in a number of battery packs and plan on getting a battery welder soon.

Likes(4)Dislikes(0)

Reply
- Parasuraman S
  
  March 9, 2024 at 3:16 pm
  
  Many thanks for your detalied response giving valuable info about batteries.
  
  Likes(1)Dislikes(0)
  
  Reply
Waleed Rishmawi

March 9, 2024 at 3:47 pm

the job of helping family memembers usually very rewarding and I am so happy you were able to help your son.
that is a very tiny UPS system. right now I am working on very big one and so far I found issue with batteries as well but I am talking about bigger two batteries that go up to 12 9 amps each. it is a lot of work but it is doable. thanks for sharing your beautiful work and experience. have a blessed day

Likes(3)Dislikes(0)

Reply
- Parasuraman S
  
  March 9, 2024 at 8:16 pm
  
  Yes dear, it is a booster! That way, we ensure that we can carry out our works with adequate support from the home! (LOL)
  
  The higher Amp work is very risky and cumbersome! All the very best!
  
  Thanks to you for your support and encouragement, dear friend!
  
  Likes(1)Dislikes(0)
  
  Reply
Albert van Bemmelen

March 9, 2024 at 5:54 pm

The explanation on how the pack was connected and upgraded was very confusing and still unclear especially where you mentioned the 3 different voltages of 1.2V, 1.8V and/or 3.3V? I sadly couldn't make any sense of it. Your recent articles often have no clear circuit drawing that would have explained everything in detail without leaving any questions. Because sadly those nice photos again didn't help at all! But I'm of course glad that you extended the active working time of this power pack for your son's router to well over 7 hours.

PS:The rubber band you used to hold the batteries together probably won't last for long why it maybe is better to use rubber seal tape here. From my work at the post delivery office I know that those rubber bands go bad fast after they have been wet, from laying in the sun, or after frequently been used.

Likes(3)Dislikes(0)

Reply
Yogesh Panchal

March 10, 2024 at 12:07 am

Good Job! Sir
Hot glue gun is handy for holding batteries to gather,Rubber band will degrade early.

Likes(1)Dislikes(0)

Reply