I have a problem/question re: the DC/DC converter and accessory battery setup.
See config and load info below. Here is the problem -
Car runs fine without the headlights.
I assume that the additional load on the accessory battery pulls more current from the DC/DC converter, which blows the fuse. And the battery is damaged so it runs down quickly.
Per info on lead acid batteries and talking with ExpertPower tech support, max amperage charging lead acid batteries should not exceed 0.25C, or 5A for a 20Ah battery. The tech support guy said I probably damaged the battery, even if I had a 20A fuse between the DC/DC converter and the battery.
What is the solution, since most DC/DC converters are >30A, and I don't see a lot of huge Ah 12V accessory batteries in the EV forum?
Thanks!
Config -
Load -
See config and load info below. Here is the problem -
- Turn car on *with headlights*
- Fuse between DC/DC converter and accessory battery blows
- Accessory battery rapidly loses voltage - within 20min
- Lights die, along with relay for motor controller
- Car stops
Car runs fine without the headlights.
I assume that the additional load on the accessory battery pulls more current from the DC/DC converter, which blows the fuse. And the battery is damaged so it runs down quickly.
Per info on lead acid batteries and talking with ExpertPower tech support, max amperage charging lead acid batteries should not exceed 0.25C, or 5A for a 20Ah battery. The tech support guy said I probably damaged the battery, even if I had a 20A fuse between the DC/DC converter and the battery.
What is the solution, since most DC/DC converters are >30A, and I don't see a lot of huge Ah 12V accessory batteries in the EV forum?
Thanks!
Config -
- Accessory battery is sealed lead acid 12v/20Ah - ExpertPower EXP12200 - https://www.amazon.com/gp/product/B00KC39BE6/ref=oh_aui_search_detailpage?ie=UTF8&psc=1
- 108V pack is connected to a DC/DC converter that outputs 13.6V, max 50A.
- Connection between DC/DC converter and the accessory battery is fused with 20A fuse.
Load -
- 1.25A - with ignition on
- 7-9A - ignition and headlights
- 10+A - driving the car with headlights, vacuum pump, PS pump, etc.