Objective: Looking to buy for or assistance with building a battery conditioner for an 18v DeWalt sawzall.
Background: I'm a volunteer fire fighter and on the rescue team of a fire and rescue department. One item we purchased about two years ago was an
18v DeWalt sawzall and three batteries. We have used this for vehicle extrications. We rotate the three batteries as 1) in the saw, 2) spare with the saw and 3) in the charger. Over the past two years, the sawzall has only been used a few times. At present, the batteries will only power the saw for about three minutes with no load.On one hand, we are happy that we have not had a lot of vehicle extrications. But, this means each battery may go for many months without any use. We would like to buy/build some sort of battery conditioner to put a load on the battery before the battery goes into the charger. We have found some conditioners for 12v systems, but nothing for an 18v system.
A couple of us non-electronic folks have talked about some sort of system that uses light bulb(s) to put a load on the battery. Along with some sort of relay that opens the load circuit when the voltage drops below some predetermined level. Maybe even including some sort of resetable timer to measure how much time it to took before the relay opened up. This may give us some indication of the overall health of the battery.
Does anyone out there have any sources for an 18v conditioner system or can someone provide some assistance in building a conditioner system?
TIA