# Re: [EVDL] Water Miser Battery Caps and or Hydrocaps



## EVDL List (Jul 27, 2007)

*Re: [EVDL] Water Miser Battery Caps and or Hydrocaps*

Back in the 70's I use the Hydrocaps from the Hydrocap Company in Florida. 
To use them, you must have a enclosed battery box with adequate fresh filter 
dry air flow coming into the battery and existing by the use of a totally 
enclose acid proof exhaust fans.

If there is to much humidity, then you have to add the absorbent pads that 
the Hydrocap Company also sells for this purpose. I did not have to use 
them, because the top of my batteries are completely dry and clean.

The recommended space above the surface of the batteries and the top of the 
lid is four inches or top of the fill neck to the lip is 3 inches. It best 
to have at least 2 inches from the top of the Hydrocap to the lid.

This is a requirement, as where the Hydrocap needs this much oxygen to 
combine with the hydrogen inside this cap which then turns the these gases 
back into a liquid form and back into the battery.

My first battery boxes were design for the 2 volt Tudor type EV batteries 
that had these 3 inch clearance. The battery boxes were 24 inches deep 
with 18 inch long 300 ah cells in them. The problem in this country, the 
boxes extended down below the body of the car and where only 6 inches above 
the ground. They were hard to keep warm at -33 F. even with a 1 inch layer 
of foam rubber that was cover in a neoprene covering and heater elements 
attach to the bottom of the box.

I therefore use a 12 inch deep box inside the bed which uses 4 inches of Dow 
blue foam that are cover with a water proof marine carpet. I want to use 
the Hydrocaps on the the standard EV 6, 8, or 12 volt batteries, but the 
Hydrocap Company said I do not have the air space above the batteries for it 
to work properly. They said, what work the best, is to install a filter dry 
air inlet and exhaust the air for 30 batteries is with a exhaust blower 
which is one of the Dayton 6 inch blowers that has the plastic wheels, with 
the internal body of the blower coated with a acid proof coating. The fan I 
amp using is rated at 150 CFM.

When I charge my battery pack, the fan must first come on, which turns on a 
air flow switch, which in turn, turn on a 50 amp Size 1 AC contactor that 
turns on the AC power between the AC power plug and battery charger. If at 
any time, the fan fails, it will then turn off the AC contact which in turn, 
turns off the charger.

There is also a on board 60 Amp 2 pole GFI breaker that will trip if there 
is too much leakage from the batteries to EV body.

If you are doing daily charging at 30 amps, then these Hydrogen caps may 
last you about 2 years for that rate of charging. Back in 1975 these 
Hydrocaps cost me $5.00 for the 300 AH @ 30 amp charging rated cap. Today 
it would add over a $1000.00 a year to use.

You have to buy plenty of spares so you can replace one that may be running 
too hot which is cause by increase gassing which may be cause by 
equalization charging.

I would use either the U.S. Battery Company automatic watering system of 
next best is the Water Miser Battery Caps.

Roland


----- Original Message ----- 
From: "EVDL Administrator" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Friday, March 13, 2009 1:43 PM
Subject: Re: [EVDL] Water Miser Battery Caps




> > On 12 Mar 2009 at 10:25, SLPinfo.org wrote:
> >
> > > Anyone have experience (pro or con) with Water Miser Battery Caps? I
> > > can't
> ...


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