Battery Isolator - Parasitic Current
Does the typical battery isolator subject the vehicle battery to any parasitic current when they're in the "cut-out" mode (secondary battery disconnected)?
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20 Replies
otrfun wrote:
MEXICOWANDERER wrote:
Haven’t purchased one yet. This isolator (and many rebranded versions of it) appear to be very popular on Amazon.
ISOLATOR covers a large territory. Which type do you have??
Looks like that thing is not really an isolator and it could allow some draw from the starting battery, but if the starting battery voltage falls below 12.8 it does get isolated? Not clear. I don't really understand what that thing is good for, but more coffee might help.theoldwizard1 wrote:
Agree. I own several clamp ammeters. Unfortunately, it's hard to measure the parasitic current of something you don't yet have or own; hence the reason for my post.
This is why every RVer should have a "clamp meter" to quickly and easily measure current.
Uni-T B4Q094 UT210E True RMS AC/DC Current Mini Clamp Meter- If you buy a clamp meter make sure that it will measure DC amps. Many of them will only measure AC.
- This is why every RVer should have a "clamp meter" to quickly and easily measure current.
Uni-T B4Q094 UT210E True RMS AC/DC Current Mini Clamp Meter - There are two basic types of battery isolators and on one of them two control systems
Diode isolators have no control system bit it is possible they may present a tiny "leakage" current.. I doubt you'd be able to measure it it's that small.
Relay isolators when isolated it's 100 percent no leakage but the control system may have a voltage sensor that "draws again a very tiny amount a very very tiny amount. - Some folks use a Trik-l-Start to maintain the Chassis battery.
otrfun wrote:
Does the typical battery isolator subject the vehicle battery to any parasitic current when they're in the "cut-out" mode (secondary battery disconnected)?
If the isolator is a relay, or solenoid, then no.- ISOLATOR covers a large territory. Which type do you have??
- With the ignition off, the isolator keeps all house loads from the starting battery. BUT the starting battery still has its own parasitic loads on it from the engine computer , dash clock etc.
Some put a small charger on the starting battery to maintain it while the RV is parked and isolator is "open", while the house batts are maintained by something else.
