Battery management

[Dan Coplan]

I have several Trimpacs that I got used. The number of cycles ranges from 111 to 461. Do I understand correctly that ideally they should all be at the same cycle life? If this is the case, should I set my older batteries aside and let the ones with fewer cycles catch up? The downside I see to this is they'll all fail right around the same time. Maybe it makes more sense to have half with the same older cycle rate and half with the same newer cycle rate(?).

 

When does a battery complete a cycle? If I put a batt back on the charger when it's only used up halfway, is that still considered a cycle or does the battery intelligently know when the amount of a full cycle has been used?

 

Any info on battery management is appreciated. Thanks.

 

Dan

[Michael Binder]

As i know, a "cycle" is a fully charge. So if the battery is only half empty and loaded, its a half cycle.

 

And because of discharging. I asked our technican and he told me, that it is ok (in my case i asked him that) if i use a new 160Wh and an old 110Wh battery at the same time. the weaker battery will be discharged more slowly than the better one. So in my case we dont use 2 good ones and 2 older ones, i mix it because of always the same output and duration of work (not to have a set of batteries i can work with about 20 minutes, and with the other set about 80 minutes).

 

Hope i could help a little bit

 

greetings

 

michael

 

ps: i was talking about li-ion-batteries

[Ron L Rathbone]

I have several Trimpacs that I got used. The number of cycles ranges from 111 to 461. Do I understand correctly that ideally they should all be at the same cycle life? If this is the case, should I set my older batteries aside and let the ones with fewer cycles catch up? The downside I see to this is they'll all fail right around the same time. Maybe it makes more sense to have half with the same older cycle rate and half with the same newer cycle rate(?).

 

When does a battery complete a cycle? If I put a batt back on the charger when it's only used up halfway, is that still considered a cycle or does the battery intelligently know when the amount of a full cycle has been used?

 

Any info on battery management is appreciated. Thanks.

 

Dan

 

Hello Dan,

 

1. A battery pack is only as strong as the weakest cell.

2. A set of two battery packs is only as strong as the weaker pack. The stronger pack attempts to do the work of both packs.

3. A premium battery pack, (ni-cd being the subject at hand), will use Saft, Sanyo, or Panasonics best manufacturing technology of sintered positive electrode "rapid" charge cells.

These cells are designed for 900-1200 charge - discharge cycles, in an ideal world. This will deteriorate with age.

3A. Anything less, Name brand good or better cells, or Chinese cells, will have less performance.

3B. Per eng spec sheets a new cell is good for up to two years if kept in a proper environment. That does not mean that a new cell will give 100% performance after being pulled from the shelf after two years. Use is the best care for your batteries.

4. Half a cycle is only half a cycle.

 

You can find more information in our FAQ's and also in our articles on rathboneenergy.com

 

Sincerely,

 

Ron L. Rathbone

Rathbone Energy, Inc.

www.rathboneenergy.com

865-484-1783