Hi question for HYBRID vehicle owners who use trickle chargers, can you please tell me which option is best. I have noco genius 5 trickle charger

1. Connect Trickle positive to + in fusebox and negative to metal
2. Connect Trickle positive to Battery + and negative to metal somewhere in cargo area
3. Connect Trickle positive to battery positive and trickle negative to battery negative
4. Same as 3rd but disconnect battery negative wire from car
from vehicle

also, Can a trickle charger damage something inside the car like DC-DC converter or anything?

Am going for 7 weeks vacation and wants to keep car in best possible condition. Thank you

 

Well 7 weeks is past recommended max of 4 weeks for hybrid, BUT it is not for the 12v battery and for the traction battery.

Back to 12v battery:

Trickle charger ---> I would use the posts in the engine bay [under the hood].
Reasons:
Posts are small and just perfect of the low current ... the only concern is if the clamps on your charger are small
The terminals are far away from the battery and any spark while connecting/disconnecting will not be near hydrogen gas.

Total disconnect of the battery to connect to the charger will disable rear hatch operation ... You will be able to shut the hatch but to get to the battery you will have to crawls from back seat.

Back to long 7 weeks without starting/running/charging the traction battery:
If the traction battery voltage falls below a minimum, your hybrid will be a beached whale. Remember the traction battery is needed to start the hybrid engine. If you ever get into this situation, you will have to flat bed the vehicle to dealer or hybrid/electric shop to charge the traction battery.

How accurate is the 4 week period ... it depends upon the health of traction battery and the depletion/discharge rate. Can yours last 7 weeks without being charged, I hope that it does. If you have some one to run it to full charge after 18 days or so would be preferred.

Salim

PS: When a circuit is completed or broken, the sudden flow/break in current produces a spark [and more hesitant a person is the contact is made or broken a few times ... called bounce] or series of sparks. When the sparks are in the vicinity of the battery which produces hydrogen and oxygen they can ignite. The circuit completion or break should happen as far as possible from the battery. So you can connect to the actual post on the battery for the first clamp, but the second clamp that completes the circuit should be far away as possible. When you disconnect the charger, the first clamp that breaks the circuit should be far away from the battery.
I was young and reckless and although I knew the chemistry, but assumed the volume of gas will be so low that it should not matter. I learnt the hard way how violent the explosion was. The battery split and luckily the acid just flowed on to porcelain sink.

 

I leave my 2011 Lexus HS250h hybrid stored outside for weeks at a time with a Solar battery maintainer that connects via the OBD2 port. You need to purchase the OBD2 connector separately as there are few solar maintainers that include it. I have done this for 8 months with no issues.