Response to Lee's comments on Todd Battery Chargers

[Joe Smalley <JoeS@WORLDFRONT.COM>]

> The Todds, as well as the Sevcons and all the other DC/DC converters =
I've
> seen are very crude as battery chargers. They are really just switching
> power supplies with a fixed DC output voltage and current limit.
>
> They can't be configured for flooded or gel cell batteries. They can't =
be
> set for the amp-hr capacity of the battery. They are not temperature
> compensated. They don't turn off, or switch to float at the end of a
> charge. They don't have an equalize mode. They don't detect a dead batt=
ery,
> or battery with a bad cell (both require a lower charging current). And
> they squeal at light load (sounds like fingernails on a blackboard).
>
> They just apply a fixed voltage (13.5v or 14.4v, jumper selectable). =
14.4v
> will charge quickly, but then fry the battery if left on. 13.5v can be =
left
> on indefinitely, but takes weeks to reach full charge.
>
> Yes, they work, but I can certainly ask for better.
>
> Lee Hart

I have worked with several configurations of Todd chargers. To address =
your above related concerns:

1. They come set up for either flooded or gelled batteries. There is a =
voltage output adjustment on the master controller board to set it. I hav=
e not seen any description of it in any literature, but my vendor told =
me about it.

2. Very few chargers have a setting for the capacity of the battery. None=
 under $300 anyway.

3. True, they are not temperature compensated.

4. I have two of them that had the float option installed. It can be adde=
d after purchase to the models with the three terminals on the end. It =
is more difficult for an internal installation on the models without the =
three terminals.

5. True, No equalize mode.

6. True, A shorted or bad cell will indeed cook the battery.

7. None of mine squeal at light loads. They click like a wind up clock =
up to about .05 amps then they are quiet.

8. Two of mine have been fitted with an externally accessable knobpot to =
adjust the end voltage. This has been used for equalization.

Joe Smalley
JoeS@worldfront.com

Response to Lee's comments on Todd Battery Chargers