Watering the Batteries …

I should have done this a long time ago.

With any deep cycle lead acid batteries you have to add distilled water to them on occasion. I’m not sure what the schedule for this is yet, but I think probably once a month or so it what I SHOULD be doing. I did not water them at all last year – although I did set aside a day to do it, it just never got done.

I took about 2 hours today and did my first watering, and the batteries sure did need it. I ended up putting about 3.5 liters of distilled water into my 6 batteries. That’s more than 1/2 liter for each battery! I’m pretty sure when you have to add water to the batteries you shouldn’t have to add this much. This could very well have been the cause of some of the range woes I’ve been having lately.

Watering the batteries is pretty simple. I have to remove a sticker that was covering the access screws to the battery cells. There are 6 plastic screws that need to be removed to add the water. Once removed you just have to have some patience pouring the water in. I’ve never watered a battery before so I hope I filled them to proper levels. I left about 1/2″ between the fluid level and the top of the hole I was pouring into. Time will tell.

Ever since the car defrosted this spring, I haven’t been able to get the pack charged over 78 volts. Last year I would get it to 81 without much trouble. Because of the lesser charge, the car was becoming sluggish long before I remember it. I chalked it up to the batteries just being run down a little, and from being frozen all winter. Now, I think it was because of fluid levels in the battery. It’s not fully charged at this point, but it started charging at 675 watts – I haven’t been able to get it to charge above 550 watts yet this year so I think I’m on the right track.

In my quest to increase range I’ve been doing a lot of research. Once very important fact that has been overlooked is motor and controller cooling. I have no cooling for these components as my front grill is completely closed off to protect the front 4 batteries. I babied the car around town for a few miles today and the controller and motor were very hot. I didn’t pull over 100 amps at any point during the trip and these still uncomfortably warm. When these components heat up you loose efficiency. I need to find a good way to keep these components cool under a proper amp load. I haven’t decided what I’m going to do yet – I’m still juggling a few ideas. I’ll post again in a few days when I come to a conclusion.